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INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 10-K

Commission file number 1-33128

ONEBEACON INSURANCE GROUP, LTD.
(Exact name of Registrant as specified in its charter)

Registrant's telephone number, including area code: (952) 852-2431

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:
None

         Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Act. Yes o    No ý

         Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Exchange Act. Yes o    No ý

         Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Exchange Act during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ý    No o

         Indicate by check mark whether the Registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes o    No o

         Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of the Registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. ý

         Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer," "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act.

         Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes o    No ý

         The aggregate market value of voting shares (based on the closing price of Class A common shares listed on the New York Stock Exchange and the consideration received for those shares not listed on a national or regional exchange) held by non-affiliates of the Registrant as of June 30, 2009, was $270,951,486.

         As of February 24, 2010, 23,366,312 Class A common shares, par value $0.01 per share, and 71,754,738 Class B common shares, par value $0.01 per share, were outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

         Portions of the Registrant's Definitive Proxy Statement to be filed with the Securities and Exchange Commission ("SEC") pursuant to Regulation 14A under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), relating to the Registrant's Annual General Meeting of Members scheduled to be held June 16, 2010 are incorporated by reference into Part III of this Form 10-K. With the exception of the portions of the Proxy Statement specifically incorporated herein by reference, the Proxy Statement is not deemed to be filed as part of this Form 10-K.

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PART I

ITEM 1.    BUSINESS

Overview

        OneBeacon Insurance Group, Ltd. (the Company or the Registrant), an exempted Bermuda limited liability company, through its subsidiaries (collectively, OneBeacon, we, us, or our) is a property and casualty insurance writer that provides a range of insurance products and services. We have historically offered a range of specialty, commercial and personal products and services sold primarily through select independent agents and brokers. However, we have recently entered into two transactions that will transform us into a specialty lines company. On December 3, 2009, we sold the renewal rights to our non-specialty commercial lines business and on February 2, 2010, we entered into a definitive agreement to sell our personal lines business.

        With roots dating back to 1831, we have been operating for more than 175 years and have relationships with many independent agencies and brokers. OneBeacon was acquired by White Mountains Insurance Group, Ltd. (White Mountains) from Aviva plc (Aviva, formerly CGNU) in 2001 (the OneBeacon Acquisition). White Mountains is a holding company whose businesses provide property and casualty insurance, reinsurance and certain other products. During the fourth quarter of 2006, White Mountains sold 27.6 million or 27.6% of our common shares in an initial public offering. Prior to the initial public offering, OneBeacon was a wholly-owned subsidiary of White Mountains. As of December 31, 2009, White Mountains owned 75.4% of our common shares.

        Our headquarters are located at 14 Wesley Street, 5th Floor, Hamilton HM 11, Bermuda. Our U.S. headquarters are located at 1 Beacon Lane, Canton, Massachusetts 02021, our principal executive office is located at 601 Carlson Parkway, Minnetonka, Minnesota 55305 and our registered office is located at Clarendon House, 2 Church Street, Hamilton HM 11, Bermuda.

        Our reportable segments are Insurance Operations, formerly known as Primary Insurance Operations, and Other Operations. We currently manage our Insurance Operations segment through a specialty lines underwriting unit and a personal lines underwriting unit, nearly all of which is subject to the personal lines transaction described below. The Insurance Operations segment also includes run-off business, which primarily consists of non-specialty commercial lines business which is being transferred to The Hanover Insurance Group (The Hanover), as described below, and other run-off business. Certain other activities are conducted through our top holding company, OneBeacon Insurance Group, Ltd., and our intermediate subsidiaries and are included in our Other Operations segment.

        Our specialty lines businesses are national in scope, while our personal lines business has been exclusively available in the eight Northeastern states (the New England states, New York and New Jersey). We have added, and expect to continue to add, new specialty businesses both organically and through acquisition, guided by our focus on profitable growth while prudently managing underwriting risk.

        Our principal operating subsidiaries are rated "A" (Excellent, the third highest of fifteen financial strength ratings) by A.M. Best Company, Inc. (A.M. Best), "A" (Strong, the sixth highest of twenty-one financial strength ratings) by Standard & Poor's Rating Service (Standard & Poor's), "A2" (Good, the sixth highest of twenty-one financial strength ratings) by Moody's Investors Service, Inc. (Moody's) and "A" (Strong, the sixth highest of twenty-one financial strength ratings) by Fitch, Inc. (Fitch).

        In 2009, our net written premiums totaled approximately $1.9 billion and we had total assets of approximately $7.5 billion and total OneBeacon's shareholders' equity of approximately $1.4 billion at December 31, 2009.

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Recent Developments

        We have recently entered into two transactions that will transform us into a specialty lines insurance company. We expect that the transactions will free up significant capital, increase our financial flexibility and also substantially reduce our catastrophe exposure.

        Commercial lines.    On December 3, 2009, we sold the renewal rights to approximately $490 million in premiums from our non-specialty commercial lines business to The Hanover. The transaction includes small commercial accounts and the non-specialty portion of the middle-market business, beginning with January 1, 2010 effective dates (the Commercial Lines Transaction). As consideration, we received $23.2 million, and will receive an additional 10% of premiums renewed in excess of $200 million for the first renewal period. We will continue to manage claims from business written prior to the Commercial Lines Transaction and for business written by The Hanover through June 30, 2010. The Hanover will reimburse us for our expenses incurred to provide the claims administration services.

        Personal lines.    On February 2, 2010, we entered into a definitive agreement to sell our personal lines business to Tower Group, Inc. (Tower) (the Personal Lines Transaction). The Personal Lines Transaction includes the sale of two insurance companies containing the personal lines business, two attorneys-in-fact managing the reciprocal insurance exchanges (reciprocals) that write the personal lines business in New York and New Jersey, and the surplus notes issued by each of the reciprocals. Net written premiums for the affected books total approximately $420 million for the year ended December 31, 2009. As consideration, we will receive an amount equal to the statutory surplus in the reciprocals (approximately $103 million at December 31, 2009, including the par value of the surplus notes issued by the reciprocals), the GAAP equity in the insurance companies and attorneys-in-fact (approximately $45 million at December 31, 2009), plus $32.5 million. AutoOne Insurance (AutoOne) is not being sold as part of this transaction. The sale is subject to certain state regulatory approvals and is expected to close in the second quarter of 2010.

Our Business Focus

        We are a specialty company as demonstrated by our focus on certain customer groups and/or geographic territories where we believe our targeted products, pricing and expertise deliver a competitive advantage. In personal lines, our flagship package product has provided a specialized approach to the market by bundling automobile, home, liability, watercraft and other coverages in a single policy. We believe that our proprietary knowledge regarding our targeted industries, classes and risk characteristics provides us with a competitive edge for our terms and conditions on individual accounts. We believe specialization will result in superior returns as compared to a more "generalist" underwriting approach.

Our Operating Principles

        We strive to operate within the spirit of four operating principles. These are:

        Underwriting Comes First.    An insurance enterprise must respect the fundamentals of insurance. There must be a realistic expectation of underwriting profit on all business written, and demonstrated fulfillment of that expectation over time, with focused attention to the loss ratio and to all the professional insurance disciplines of pricing, underwriting and claims management.

        Maintain a Disciplined Balance Sheet.    The first concern here is that insurance liabilities must always be fully recognized. Loss reserves and expense reserves must be solid before any other aspect of the business can be solid. Pricing, marketing and underwriting all depend on informed judgment of ultimate loss costs and that can be managed effectively only with a disciplined balance sheet.

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        Invest for Total Return.    Historical insurance accounting tends to hide unrealized gains and losses in the investment portfolio and over-reward reported investment income (interest and dividends). Regardless of the accounting, we must invest for the best growth in after tax value over time. In addition to investing our bond portfolios for total after tax return, that will also mean prudent investment in a balanced portfolio consistent with leverage and insurance risk considerations.

        Think Like Owners.    Thinking like owners has a value all its own. There are stakeholders in a business enterprise and doing good work requires more than this quarter's profit. But thinking like an owner embraces all that without losing the touchstone of a capitalist enterprise.

Property and Casualty Insurance Overview

        Generally, property and casualty insurance companies write insurance policies in exchange for premiums paid by their customers (the insured). An insurance policy is a contract between the insurance company and the insured where the insurance company agrees to pay for losses suffered by the insured that are covered under the contract. Such contracts often are subject to subsequent legal interpretation by courts, legislative action and arbitration. Property insurance generally covers the financial consequences of accidental losses to the insured's property, such as a home and the personal property in it, or a business' building, inventory and equipment. Casualty insurance (often referred to as liability insurance) generally covers the financial consequences of a legal liability of an individual or an organization resulting from negligent acts and omissions causing bodily injury and/or property damage to a third party. Claims on property coverage generally are reported and settled in a relatively short period of time, whereas those on casualty coverage can take years, even decades, to settle.

        We derive substantially all of our revenues from earned premiums, investment income and net realized and unrealized gains and losses on investment securities. Earned premiums represent premiums received from insureds, which are recognized as revenue over the period of time that insurance coverage is provided (i.e., ratably over the life of the policy). A significant period of time normally elapses between the receipt of insurance premiums and the payment of insurance claims. During this time, we invest the premiums, earn investment income and generate net realized and unrealized investment gains and losses on investments.

        Insurance companies incur a significant amount of their total expenses from policyholder losses, which are commonly referred to as claims. In settling policyholder losses, various loss adjustment expenses (LAE) are incurred such as insurance adjusters' fees and litigation expenses. In addition, insurance companies incur policy acquisition expenses, such as commissions paid to agents and premium taxes, and other expenses related to the underwriting process, including their employees' compensation and benefits.

        The key measure of relative underwriting performance for an insurance company is the combined ratio. An insurance company's combined ratio under accounting principles generally accepted in the United States (GAAP) is calculated by adding the ratio of incurred loss and LAE to earned premiums (the loss and LAE ratio) and the ratio of policy acquisition and other underwriting expenses to earned premiums (the expense ratio). A combined ratio under 100% indicates that an insurance company is generating an underwriting profit. However, when considering investment income and investment gains or losses, insurance companies operating at a combined ratio of greater than 100% can be profitable.

Insurance Operations

        Our Insurance Operations segment includes specialty lines and personal lines insurance products and services. The Insurance Operations segment also includes run-off business, which primarily consists of non-specialty commercial lines business which is being transferred to The Hanover, as well as national accounts, certain specialty programs and regional agency business transferred to Liberty Mutual Insurance Group (Liberty Mutual) effective November 1, 2001. See "Business—Run-off".

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        For the years ended December 31, 2009, 2008 and 2007, our net written premiums by line of business were as follows:

Specialty lines

        Specialty lines is a collection of niche businesses that focus on solving the unique needs of particular customer or industry groups on a national scale. We provide distinct products and offer tailored coverages and services, managed by seasoned teams of market specialists. These businesses maintain stand-alone operations and distribution channels targeting their specific customer groups. Our specialty lines include several businesses focused on smaller property-casualty insurance segments where particular expertise and relationships with similarly focused distribution partners has resulted historically in strong operating results. These businesses maintain their competitive advantage through a deep knowledge of their respective customers and markets. Our specialty lines businesses currently include:

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OneBeacon Professional Insurance (OBPI):  OBPI, formerly known as OneBeacon Professional Partners, specializes in professional liability insurance products for an increasingly broad range of industry groups. OBPI's original focus on health-care related liability insurance continues while expansion into non-health-care related liability insurance segments has increased over the last five years. Medical liability insurance for health-care industry segments, including hospitals, physician groups, managed care organizations, long-term care facilities and other non-hospital medical facilities, represents the most significant share of OBPI's business. Additionally, OBPI offers stop loss insurance to certain health-care providers through its provider excess insurance and HMO reinsurance products. Errors and omissions liability insurance coverage is also provided to business segments including design professionals for the construction industry, law firms, in-house counsel, realtors and media organizations. Management liability coverage, specifically directors and officers and employment practices insurance, is offered on a limited basis to some of the business segments noted above. Underwriting, claims and risk control services are managed internally. OBPI's policies are primarily issued on a "claims made" basis, which covers losses reported during the time period when a liability policy is in effect, regardless of when the event causing the claim actually occurred.



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Collector Cars and Boats:  In the second quarter of 2008, we began to provide property and casualty insurance solutions through an exclusive partnership with Hagerty Insurance Agency and Hagerty Classic Marine Insurance Agency (Hagerty), the nation's premier collector car and classic boat agencies. Hagerty's specialty services include collector car and wooden boat

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insurance, automotive museum insurance, restoration shop insurance, vehicle valuation, financing and roadside assistance, as well as a variety of useful information resources. Its Hagerty Plus community of collector-car enthusiasts has over 280,000 members. Hagerty works proactively on hobby advocacy and supports the Collectors Foundation, a nonprofit organization formed by Hagerty and dedicated to the preservation of the hobby.

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International Marine Underwriters (IMU):  A leading provider of marine insurance, this business traces its roots back to the early 1900s. IMU coverages include physical damage or loss and general liability for cargo and commercial hull, both at primary and excess levels. IMU also offers coverage for marinas, including a "package" product with comprehensive property and liability coverage, and yachts, the offerings for which were strengthened by IMU's acquisition in October 2006 of yacht-specialist National Marine Underwriters, Inc., a yacht insurance managing general agency. IMU does not offer offshore energy products. Target customers include ferry operators and charter boats (hull), marina operators and boat dealers (package product) and private-pleasure yachts.



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Technology:  Technology's customer groups include hardware manufacturers, software companies, and telecommunications service providers. Our custom @vantage for Technology policies provides coverage for technology customers' unique needs including specialized professional liability such as data privacy, communications and errors and omissions liability, both domestically and internationally. Within the Technology segment, we also specialize further with a product tailored for medical technology customers available on a claims-made or occurrence basis and that also provides protection worldwide. Within this class, we target medical device manufacturers and operations.



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Property and Inland Marine (PIM):  The PIM segment provides monoline property and inland marine products. Our property focus is on the real estate, health care, education, aviation, municipality and manufacturing sectors, while inland marine targets the construction, transportation and fine arts segments. We deliver creative and tailored solutions that fit our customers' unique needs through broad coverage forms, specialized risk control and claims handling capabilities.



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A.W.G. Dewar (Dewar):  A leading provider of tuition reimbursement insurance since 1930, Dewar's product protects both schools and parents from the financial consequences of a student's withdrawal or dismissal from school. The tuition refund plan reimburses parents up to 100% of tuition, room and board fees when a student is obliged to leave school due to covered reasons, such as medical or expulsion. Dewar provides customized policies to independent schools and colleges in North America.



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Specialty Accident and Health (A&H):  A&H provides accident insurance principally to employer groups, associations and affinity groups. A&H's products include corporate accident, travel accident and occupational accident coverage which is primarily targeted to the trucking industry. In the fourth quarter of 2008, A&H launched OneBeacon Services to provide employer and affinity groups with access to a suite of services to help manage today's emerging issues. Services include a discounted prescription drug program, identity theft resolution services and travel assistance services. The A&H group distributes products through independent agents and brokers, and selectively markets directly to customers.



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Entertainment Brokers International Insurance Services (EBI):  Acquired in the third quarter of 2008, EBI provides specialized commercial insurance products, including professional liability coverages, for the entertainment, sports and leisure industries. EBI continues to operate as a managing agency with a network of 500 independent agents and brokers. EBI also operates a brokerage operation offering excess workers compensation coverages and a high value homeowners product.

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Financial Services:  The Financial Services segment commenced operations in October 2005 by targeting a broad range of financial services companies including credit unions, investment advisors, securities broker/dealers, insurance companies and commercial banks. Through our @vantage for Financial Services product we provide customers with broad property and general liability protection. For community banks with under $3 billion in assets, the product may be augmented with specialized professional liability coverages.



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OneBeacon Specialty Property (OBSP):  OBSP provides protection against certain damages over and above those covered by primary policies or a large self-insured retention. Target classes include apartments and condominiums, commercial real estate, small-to-medium manufacturing, retail/wholesale and public entity and educational institutions. OBSP targets customers with low catastrophe-exposed risks. Our OBSP solutions are provided primarily through surplus lines wholesalers in all 50 states and the District of Columbia.



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OneBeacon Government Risks (OBGR):  Formed in March 2007, this group offers property and casualty products for government entities. The products include automobile, property, general liability and professional liability coverages. The professional liability offerings consist of law enforcement, public officials and employment practice coverage. Markets served include cities, towns, townships, counties, transit authorities, government agencies, special districts and pools (groups of public entities). OBGR strategically distributes its products through agents and brokers.



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OneBeacon Energy (OBEG):  OBEG began offering property and casualty products in July 2009 to companies engaged in traditional upstream and midstream oil and gas production, storage and distribution and companies who use renewable energy resources to generate power or produce alternative fuels. OBEG's coverages include monoline property, monoline general liability, general liability combined with automobile liability and lead umbrella. All coverages offered are specifically tailored for these markets and risks. OBEG does not offer offshore energy products. Market-leading agents and brokers that specialize in the energy business strategically distribute OBEG's products throughout the United States.

        For the years ended December 31, 2009, 2008 and 2007, our specialty lines net written premiums were as follows:

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Personal lines

        Our personal lines underwriting unit is comprised of traditional personal lines, which is subject to the Personal Lines Transaction, and AutoOne. The Personal Lines Transaction is subject to certain state regulatory approvals and is expected to close in the second quarter of 2010.

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Traditional personal lines:  Our traditional personal lines has provided a comprehensive suite of personal insurance products sold through select independent agents with a focus on eight Northeastern states. Our personal lines products include:



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Automobile:  consists of physical damage and liability coverage. Automobile physical damage insurance covers loss or damage to vehicles from collision, vandalism, fire, theft or other causes. Automobile liability insurance covers bodily injury of others, damage to their property and costs of legal defense resulting from a collision caused by the insured.



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Homeowners:  covers losses to an insured's home, including its contents, as a result of weather, fire, theft and other causes, and losses resulting from liability for acts of negligence by the insured or the insured's immediate family. We also offer identity theft resolution assistance and identity theft expense reimbursement coverage as part of our homeowners policies.



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Package:  consists of customized combination policies offering home and automobile coverage with optional umbrella and boatowners coverage.

Within traditional personal lines, in addition to automobile, homeowners and package policy offerings, we also include management services provided to reciprocals and the consolidation of the reciprocals described below.

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Traditional personal lines excluding reciprocals:  To maintain a high degree of flexibility, in 2004 we created a highly segmented product suite, called OneChoice, under which we offer risk-adjusted product and pricing to our customers. OneChoice is a multi-tiered product suite that enables us to offer a broader range of coverages to a full spectrum of customers through more sophisticated pricing models that have a greater statistical correlation between historical loss experience and price than traditional pricing models. This product suite offers both automobile and homeowners coverages as well as package policies such as OneChoice CustomPac, our flagship package policy. OneChoice products rely on multiple, objective pricing tiers and rules-based underwriting that enable agents to offer OneBeacon solutions to a broad array of their customers and increase our market penetration. We regularly refine our product features and rating plans to optimize target market production. Ease of use is a critical aspect of this business. Investments in technology have provided opportunities for agents to access OneChoice through either our web-based proprietary agent portal or through comparative raters.



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Reciprocals:  We provide management services for a fee to three reciprocal insurance exchanges, which we refer to as reciprocals. The reciprocals offer the OneChoice product as described above. We have created and capitalized the reciprocals by lending them funds in exchange for surplus notes. Reciprocals are policyholder-owned insurance carriers organized as unincorporated associations. We have no ownership interest in these reciprocals. As required by GAAP, our consolidated financial statements reflect the consolidation of these reciprocals. See Note 14—"Variable Interest Entities" of the accompanying consolidated financial statements.



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AutoOne:  AutoOne is a market leader in "assigned risk" business in New York. Assigned risk plans provide automobile insurance for individuals unable to secure coverage in the voluntary

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market. Insurance carriers are obliged to accept future assignments from state assigned risk pools as a condition of maintaining a license to write automobile business in the state. However, carriers may satisfy their assigned risk obligation by buying out of their assignments through an agreement with an approved Assigned Risk Servicing Company or limit their assignments through the purchase and transfer of "credits" (for example, take-out, territorial and youthful driver credits). AutoOne offers services known as Limited Assignment Distribution, or LAD, and Commercial Limited Assignment Distribution, or CLAD, and credit programs to insurance carriers. AutoOne provides 28 LAD and CLAD programs in 21 states and the District of Columbia where assigned risk obligations may be assumed by a servicing carrier under a negotiated fee arrangement.

AutoOne also writes "voluntary take-out business" (policies "taken out" of the assigned risk pool and written in the voluntary market) by selecting policies from the assigned risk business it has assumed for its clients and from select insurance brokers that replace their clients' assigned risk policies with AutoOne policies. AutoOne receives credits for all premium taken out of the assigned risk plan which it can use either to reduce its future assigned risk obligations or sell to other carriers that can use the credits to reduce their own quota obligations.

        For the years ended December 31, 2009, 2008 and 2007, our personal lines net written premiums were as follows:

Run-off

        Run-off consists of non-specialty commercial lines business included in the Commercial Lines Transaction, as well as national accounts, certain specialty programs and regional agency business transferred to Liberty Mutual effective November 1, 2001.

        On December 3, 2009, we sold the renewal rights to our non-specialty commercial lines business to The Hanover. The transaction includes small commercial accounts and the non-specialty portion of the middle-market business, beginning with January 1, 2010 effective dates (commercial run-off). We will continue to manage claims from our non-specialty commercial lines policies written prior to the January 1, 2010 effective date of the Commercial Lines Transaction.

        Beginning in 2001, national accounts and certain specialty programs were discontinued. On November 1, 2001, we transferred our regional agency business, agents and operations in 42 states and the District of Columbia to Liberty Mutual pursuant to a renewal rights agreement (the Liberty Agreement). The Liberty Agreement pro-rated results so that OneBeacon assumed approximately two-thirds of the operating results from renewals through October 31, 2002 and approximately one-third of the operating results from renewals through October 31, 2003. The renewal rights under the Liberty Agreement expired on October 31, 2003. We continue to manage claims from the discontinued national accounts and specialty programs business as well as the claims related to the business that was subject to the Liberty Agreement (legacy run-off).

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        For the years ended December 31, 2009, 2008 and 2007, our net written premiums from run-off were as follows:

Geographic Concentration

        Our net written premiums are derived solely from business produced in the United States.

        Business from specialty lines was produced in the following states:

        Business from personal lines was produced in the following states:

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        Business from run-off was produced in the following states:

        As a result of the Commercial Lines Transaction and the Personal Lines Transaction, we expect our geographic premium distribution going forward to be consistent with our historical specialty lines premiums.

Marketing and Distribution

        We offer our products through a network comprised of independent agents, regional and national brokers and wholesalers. Our distribution relationships consist of approximately 3,400 agencies and brokers. In recent years, we have expanded our distribution channels to include select managing general agencies (MGAs), either through acquisitions or exclusive relationships. These MGAs focus on a particular customer group with tailored products and services, and related expertise.

        Our specialty lines businesses are managed from locations logistically appropriate to their target markets. OBPI is based in Avon, Connecticut and distributes its products through select national and regional brokers and agents. IMU is headquartered in New York City and operates through ten locations throughout the United States. Its products are distributed through a network of select agencies that specialize in marine business. Our collector cars and boats business is written through an exclusive MGA relationship with Hagerty. This relationship has an initial term of 5 years and will be up for renewal in the second quarter of 2013. Dewar's affiliate, A.W.G. Dewar Agency, which is located in Quincy, Massachusetts, distributes tuition refund products to independent schools and colleges throughout North America. A&H conducts business through independent agents and brokers and selectively markets directly to customers. EBI, an MGA, sells directly and through a network of independent agents through locations in New York City and California. OBGR strategically distributes its products through agents and brokers. OBEG sells through a network of regional agencies and brokers that specialize in the energy industry. Technology, Financial Services, PIM and OBSP are distributed through a network of select independent insurance agencies.

        Personal lines products are exclusively available in the eight northeastern states through a network of select independent insurance agencies.

        We protect the integrity of our franchise value by selectively appointing agents that demonstrate business and geographic profiles that align with our target markets and specialized capabilities. We believe in the added value provided by independent insurance agents and brokers as they conduct more complete assessments of their clients' needs, which result in more appropriate coverages and prudent

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risk management. We also believe that independent agents and brokers will continue to be a significant force in overall industry premium production.

        New York-based AutoOne markets its LAD and CLAD services and New York take-out credits directly to insurance carriers seeking assigned risk solutions. AutoOne generates take-out credits by writing policies from select insurance brokers that were previously in the New York Automobile Insurance Plan (NYAIP), and sells these credits to insurance companies subject to NYAIP assignments.

Underwriting and Pricing

        We believe there must be a realistic expectation of attaining an underwriting profit on all the business we write, as well as a demonstrated fulfillment of that expectation over time. Consistent with our "underwriting comes first" operating principle, adequate pricing is a critical component for achieving an underwriting profit. We underwrite our book with a disciplined approach towards pricing our insurance products and are willing to forgo a business opportunity if we believe it is not priced appropriately to the exposure.

        We use tiered rating plans in personal lines that permit us to offer more tailored price quotes to our customers based on underwriting criteria applicable to each tier. The enhanced accuracy and precision of our rate plans enable us to more confidently price our products to the exposure, and thereby permit our agency partners to deliver solutions to a broader range of customers.

        We also actively monitor pricing activity and measure usage of tiers, credits, debits and limits. In addition, we regularly update base rates to achieve targeted returns on capital and attempt to shift writings away from lines and classes where pricing is inadequate. To the extent changes in premium rates, policy forms or other matters are subject to regulatory approval (see "Regulatory Matters—General" and "Risk Factors—Regulation may restrict our ability to operate"), we proactively monitor our pending regulatory filings to facilitate, to the extent possible, their prompt processing and approval. Lastly, we expend considerable effort to measure and verify exposures and insured values.

Claims Management

        Effective claims management is a critical factor in achieving satisfactory underwriting results. We maintain an experienced staff of appraisers, medical specialists, managers, staff attorneys and field adjusters strategically located throughout our operating territories. We also maintain a special investigative unit designed to detect insurance fraud and abuse and support efforts by regulatory bodies and trade associations to curtail fraud.

        Claims are separately organized by the respective operations. Through 2009, claims have been organized by specialty, commercial, personal and run-off operations. (No change has been made within claims management related to business subject to the Commercial Lines Transaction.) This approach allows us to better identify and manage claims handling costs. In addition, a shared claims service unit manages costs related to both staff and vendors. We have adopted a total claims cost management approach that gives equal importance to controlling claims handling expenses, legal expenses and claims payments, enabling us to lower the sum of the three. This approach requires the utilization of a considerable number of conventional metrics to monitor the effectiveness of various programs implemented to lower total loss costs. The metrics are designed to guard against implementation of expense containment programs that will cost us more than we expect to save.

        Our claims department utilizes a claims workstation to record reserves, payments and adjuster activity and, with support from expert tools, assists each claim handler in the identification of recovery potential, estimating property damage, evaluating claims and identifying fraud. Our commitment and performance in fighting insurance fraud has reduced claim costs and aided law enforcement

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investigations. Under our staff counsel program, our in-house attorneys defend the majority of new lawsuits, which has resulted in savings when compared to the cost of using outside counsel.

        Calendar year reported claims in our legacy run-off operations, which excludes business subject to the Commercial Lines Transaction, were 1,387 in 2009, compared to 1,600 in 2008, a 13% reduction, in part due to the lapse of time and the nature of these run-off operations. These levels of reported claims are down from 1,800 in 2007, 2,400 in 2006 and 3,400 in 2005. Total open claims for legacy run-off operations were 3,963 at December 31, 2009, compared to 4,600 at December 31, 2008, a 14% reduction, which reflects the success of our focus on settling claims from our legacy run-off operations. Total open claims for legacy run-off operations were 5,500, 7,300 and 10,200 as of December 31, 2007, 2006 and 2005, respectively.

        In connection with the OneBeacon Acquisition, Aviva caused us to purchase a reinsurance contract with National Indemnity Company (NICO) to help protect against potential asbestos and environmental (A&E) claims relating to the pre-acquisition period prior to 2001 (the NICO Cover). See "Business—Reinsurance Protection and Catastrophe Management." NICO has retained a third party administrator (TPA), Resolute New England (Resolute), formerly Cavell USA, to manage the claims processing for A&E claims reinsured under the NICO Cover. Our claims department personnel are consulted by NICO and Resolute on major claims. As with all TPAs, claims department personnel continually monitor Resolute to ensure its controls, processes and settlements are appropriate. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Estimates—Asbestos and Environmental Reserves."

Reinsurance Protection and Catastrophe Management

        In the normal course of our business, we purchase reinsurance from high-quality, highly rated, third party reinsurers in order to minimize loss from large risks or catastrophic events.

        The timing and size of catastrophe losses are unpredictable and the level of losses experienced in any year could be material to our operating results and financial position. Examples of catastrophes include losses caused by earthquakes, wildfires, hurricanes and other types of storms and terrorist acts. The extent of losses caused by catastrophes is a function of the amount and type of insured exposure in an area affected by the event as well as the severity of the event. We use models (primarily AIR Version 11) to estimate the probability of the occurrence of a catastrophic event as well as potential losses under various scenarios. We use this model output in conjunction with other data to manage our exposure to catastrophe losses through individual risk selection and by limiting our concentration of insurance written in catastrophe-prone areas such as coastal regions. In addition, we impose wind deductibles on existing coastal windstorm exposures. We believe that our largest single event natural catastrophe exposures are Northeastern United States windstorms and California earthquakes.

        We seek to further reduce our potential loss from catastrophe exposures through the purchase of catastrophe reinsurance. Effective July 1, 2009, we renewed our property catastrophe reinsurance program through June 30, 2010. The program provides coverage for our personal and commercial property business as well as certain acts of terrorism. Under the program, the first $100 million of losses resulting from any single catastrophe are retained and the next $750 million of losses resulting from the catastrophe are reinsured. Any loss above $850 million would be retained. In the event of a catastrophe, our property catastrophe reinsurance program is reinstated for the remainder of the original contract term by paying a reinstatement premium that is based on the percentage of coverage reinstated and the original property catastrophe coverage premium. We anticipate that the $850 million limit is sufficient to cover Northeast windstorm losses with a 0.4%-0.5% probability of occurrence (1-in-250-year event to 1-in-200-year event).

        Effective January 1, 2009, we entered into a quota share agreement with a group of reinsurers to cede 30% of written premiums from our Northeast homeowners business written through OneBeacon

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Insurance Company (OBIC) and its subsidiary companies, along with Adirondack Insurance Exchange (Adirondack Insurance) and New Jersey Skylands Insurance Association (New Jersey Skylands) in New York and New Jersey, respectively. The program provides supplemental protection to previously established reinsurance described above. The reinsurers are all rated "A" (Excellent, the third highest of fifteen financial strength ratings) or better by A.M. Best. Effective January 1, 2010, we renewed the quota share agreement.

        Our property catastrophe reinsurance program does not cover personal or commercial property losses resulting from nuclear events or biological, chemical or radiological terrorist attacks or losses resulting from acts of terrorism as defined under the Terrorism Risk Insurance Act of 2002 (the Terrorism Act or TRIA), as amended, committed by an individual or individuals acting on behalf of any foreign person or foreign interest. See "Business—Terrorism."

        As described above, in December 2009, we completed the Commercial Lines Transaction. This business will run off throughout 2010, reducing our overall catastrophe profile. We anticipate that the Commercial Lines Transaction will result in a reduction in our exposure to Northeast windstorm losses in 2010. Additionally, in February 2010, we announced the Personal Lines Transaction. The closing of the Personal Lines Transaction is subject to certain regulatory approvals and is expected to close in the second quarter of 2010. Upon closing, we anticipate that the Personal Lines Transaction will significantly reduce our Northeast windstorm exposures.

        We also purchase individual property reinsurance coverage for certain risks to reduce large loss volatility. The property-per-risk reinsurance program reinsures losses in excess of $10 million up to $100 million. Individual risk facultative reinsurance may be purchased above $100 million where we deem it appropriate. The property-per-risk treaty also provides one limit of reinsurance protection for losses in excess of $10 million up to $100 million on an individual risk basis for terrorism losses. However, nuclear, biological, chemical and radiological terrorist attacks are not covered.

        We also maintain a casualty reinsurance program that provides protection for individual risk or catastrophe losses involving workers compensation, general liability, automobile liability, professional liability or umbrella liability in excess of $6 million up to $81 million. Corporate accident losses are covered up to $95 million excess of $35 million. This program provides coverage for terrorism losses but does not provide coverage for losses resulting from nuclear, biological, chemical or radiological terrorist attacks.

        In addition, we have reinsurance contracts with two reinsurance companies rated "AA+" (Very Strong, the second highest of twenty-one financial strength ratings) by Standard & Poor's and "A++" (Superior, the highest of fifteen financial strength ratings) by A.M. Best. One is the reinsurance cover with NICO which entitles us to recover up to $2.5 billion in ultimate loss and LAE incurred related primarily to A&E claims arising from business written by our predecessor prior to 1992 and 1987, respectively and certain other exposures. As of December 31, 2009, we have ceded estimated incurred losses of approximately $2.2 billion to the NICO Cover. Net losses paid totaled $1.2 billion as of December 31, 2009, with $118.0 million paid in 2009. The other contract is a reinsurance cover with General Reinsurance Corporation (GRC) for up to $570 million of additional losses on all claims arising from accident years 2000 and prior (the GRC Cover). As of December 31, 2009, we have ceded estimated incurred losses of $550 million to the GRC Cover. Pursuant to the GRC Cover, we are not entitled to recover losses to the full contract limit if such losses are reimbursed by GRC more quickly than anticipated at the time the contract was signed. We intend to seek reimbursement from GRC only for claims which result in payment patterns similar to those supporting our recoverables recorded pursuant to the GRC Cover. The economic cost of not submitting certain other eligible claims to GRC is primarily the investment spread between the rate credited by GRC and the rate achieved by us on our own investments. This cost, if any, is expected to be nominal.

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        Reinsurance contracts do not relieve us of our obligations. Therefore, collectibility of balances due from reinsurers is critical to our financial strength. See Note 4—"Reinsurance" of the accompanying consolidated financial statements.

Terrorism

        Since the terrorist attacks of September 11, 2001, we have sought to mitigate the risk associated with any future terrorist attacks by limiting the aggregate insured value of policies in geographic areas with exposure to losses from terrorist attacks. This is accomplished by either limiting the total insured values exposed, or, where applicable, through the use of terrorism exclusions.

        In December 2007, the United States government extended the Terrorism Act for seven more years until December 31, 2014. The Terrorism Act, originally enacted in 2002, established a federal "back-stop" for commercial property and casualty losses, including workers compensation, resulting from acts of terrorism by or on behalf of any foreign person or foreign interest. As extended, the law now also covers domestic acts of terrorism. The law limits the industry's aggregate liability by requiring the federal government to share 85% of certified losses once a company meets a specific retention or deductible as determined by its prior year's direct written premiums and limits the aggregate liability to be paid by the government and industry without further action by Congress at $100 billion. In exchange for this "back-stop," primary insurers are required to make coverage available to commercial insureds for losses from acts of terrorism as specified in the Terrorism Act. The following types of coverage are excluded from the program: commercial automobile, burglary and theft, surety, farmowners multi-peril and all professional liability coverage except directors and officers coverage.

        We estimate our individual retention level for commercial policies subject to the Terrorism Act to be approximately $177 million in 2010. The federal government will pay 85% of covered terrorism losses that exceed our or the industry's retention levels in 2010, up to a total of $100 billion.

        Our current property and casualty catastrophe reinsurance programs provide coverage for both "certified" and "non-certified" events as defined under the Terrorism Act provided such losses are not the result of a nuclear, biological, chemical or radiological terrorist attack, or for "certified" acts committed by an individual or individuals acting on behalf of any foreign person or foreign interest. See "Business—Reinsurance Protection and Catastrophe Management."

        We closely monitor and manage our concentration of risk by geographic area. Our guideline is to control our exposures so that our total maximum expected loss from a likely terrorism event within any half-mile radius in a metropolitan area or around a target risk will not exceed $200 million, or $300 million in all other areas. Reports monitoring our terrorism exposures are generated quarterly, and the exposure of potential new business located in areas of existing concentration or that individually present significant exposure is evaluated during the underwriting process. As a result, we believe that we have taken appropriate actions to limit our exposure to losses from terrorist attacks and will continue to monitor our terrorism exposure in the future. Nonetheless, risks insured by us, including those covered by the Terrorism Act, remain exposed to terrorist attacks and the possibility remains that losses resulting from future terrorist attacks could prove to be material.

        We expect that the Commercial Lines Transaction will reduce the terrorism exposure profile as this business runs off throughout 2010.

Loss and LAE Reserves

        We establish loss and LAE reserves that are estimates of amounts needed to pay claims and related expenses in the future for insured events that have already occurred. The process of estimating reserves involves a considerable degree of judgment by management and, as of any given date, is inherently uncertain. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Estimates."

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        The following tables summarize our loss and LAE reserve activities for the years ended December 31, 2009, 2008 and 2007:

 

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        The following information presents (1) our reserve development over the preceding 10 years and (2) a reconciliation of reserves in accordance with accounting principles and practices prescribed or permitted by insurance authorities (statutory basis) to such reserves determined in accordance with GAAP, each as prescribed by Securities Act Industry Guide No. 6.

        Section I of the 10-year table shows the estimated liability that was recorded at the end of each of the indicated years for all current and prior accident year unpaid loss and LAE. The liability represents the estimated amount of loss and LAE for claims that were unpaid at the balance sheet date, including incurred but not reported, or IBNR, reserves. In accordance with GAAP, the liability for unpaid loss and LAE is recorded in the balance sheet gross of the effects of reinsurance with an estimate of reinsurance recoverables arising from reinsurance contracts reported separately as an asset. The net balance represents the estimated amount of unpaid loss and LAE outstanding as of the balance sheet date, reduced by estimates of amounts recoverable under reinsurance contracts.

        Section II shows the cumulative amount of net loss and LAE paid relating to recorded liabilities as of the end of each succeeding year. Section III shows the re-estimated amount of the previously recorded net liability as of the end of each succeeding year. Estimates of the liability for unpaid loss and LAE are increased or decreased as payments are made and more information regarding individual claims and trends, such as overall frequency and severity patterns, becomes known. Section IV shows the cumulative net (deficiency)/redundancy representing the aggregate change in the liability from original balance sheet dates and the re-estimated liability through December 31, 2009. Section V shows the re-estimated gross liability and re-estimated reinsurance recoverables through December 31, 2009. Section VI shows the cumulative gross (deficiency)/redundancy representing the aggregate change in the liability from original balance sheet dates and the re-estimated liability through December 31, 2009.

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        The cumulative net redundancy/(deficiency) in the table above reflects reinsurance recoverables recorded under the NICO Cover and the GRC Cover. These covers apply to losses incurred in 2000 and prior years. As a result, they have the effect of significantly increasing our reinsurance recoverables in 2001 and reducing our net reserve deficiency for each of the years presented prior to 2001 by the amount of the gross reserves ceded at the time these covers were purchased. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Estimates."

        In 2005, we increased our best estimate of gross losses related to the NICO contract by $841 million ($353 million net of other third party reinsurance) as a result of a study of our A&E exposures. This had the effect of increasing the gross reserve deficiency for calendar years 2004 and prior. During 2008, we completed a new study of our A&E exposures. This did not result in a significant change to our best estimate of gross losses related to the NICO contract. As a result of the study, we increased our best estimate of incurred losses ceded to NICO, net of underlying reinsurance, by $83.4 million. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Estimates."

        The following table reconciles loss and LAE reserves for our Insurance Operations determined on a statutory basis to loss and LAE reserves determined in accordance with GAAP at December 31, as follows:

Other Operations

        Our Other Operations segment consists of the activities of OneBeacon Insurance Group, Ltd. and our intermediate subsidiary holding companies which include OneBeacon U.S. Enterprises Holdings, Inc. (OBEH), formerly known as Fund American Enterprises Holdings, Inc., and OneBeacon U.S. Holdings, Inc. (OBH), formerly known as Fund American Companies, Inc., both U.S.-domiciled companies, as well as various intermediate holding companies domiciled in the United States, Gibraltar, Luxembourg and Bermuda. Our Other Operations segment primarily consists of financing activities, purchase accounting adjustments relating to the OneBeacon Acquisition, other assets and liabilities, and general and administrative expenses incurred at the holding company level.

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        In May 2003, OBH issued $700.0 million face value of senior unsecured debt (the Senior Notes) through a public offering, at an issue price of 99.7%. The Senior Notes bear an annual interest rate of 5.875%, payable semi-annually in arrears on May 15 and November 15, until maturity on May 15, 2013. During 2009, OBH repurchased $10.6 million of outstanding Senior Notes for $8.1 million, which resulted in a $2.5 million gain. During 2009, OBIC purchased $58.3 million of outstanding Senior Notes for $55.0 million, which resulted in a $2.9 million gain. During 2008, OBH repurchased $24.0 million of the outstanding Senior Notes for $22.3 million, which resulted in a $1.6 million gain.

        White Mountains currently provides an irrevocable and unconditional guarantee as to the payment of principal and interest (the Guarantee) on the Senior Notes. In consideration of this Guarantee, we have agreed to pay White Mountains a specified fee in the amount of 25 basis points per annum on the outstanding principal amount of the Senior Notes. We have further agreed that if White Mountains' voting interest in us ceases to represent more than 50% of all our voting securities, we will redeem, exchange or otherwise modify the Senior Notes in order to fully and permanently eliminate White Mountains' obligations under the Guarantee. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Financing".

        As part of the financing for the OneBeacon Acquisition, Berkshire Hathaway Inc. (Berkshire), invested a total of $300 million in cash, of which (1) $225 million was for the purchase of cumulative non-voting preferred stock of OBH (the Berkshire Preferred Stock), which had a $300 million redemption value; and (2) $75 million was for the purchase of warrants to acquire 1,724,200 common shares of White Mountains. The Berkshire Preferred Stock was entitled to a dividend of no less than 2.35% per quarter through May 31, 2008. The Berkshire Preferred Stock was redeemed in the second quarter of 2008 for $300 million, its redemption value.

        Also in connection with the OneBeacon Acquisition, Zenith Insurance Company (Zenith) purchased $20 million in cumulative non-voting preferred stock of OBEH (the Zenith Preferred Stock). The Zenith Preferred Stock was entitled to a dividend of no less than 2.5% per quarter through June 30, 2007. At our option, the Zenith Preferred Stock was redeemed in the second quarter of 2007 for $20 million, its redemption value.

        In connection with our initial public offering, we created two irrevocable grantor trusts and funded them with assets sufficient to provide for the remaining dividend and redemption payments for the $300 million Berkshire Preferred Stock and the $20 million Zenith Preferred Stock. The creation and funding of the trusts did not legally defease the preferred stock nor create any additional rights for the holders of the preferred stock either in the trusts or otherwise, although the assets in the trusts were segregated from our other general assets and were not available for any use other than the payment of the Berkshire Preferred Sock and the Zenith Preferred Stock. Assets held in one of the trusts were used to redeem the Zenith Preferred Stock in June 2007, for $20 million, its redemption value, while assets held in the remaining trust were used to redeem the Berkshire Preferred Stock in May 2008, for $300 million, its redemption value. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Economic Defeasance".

Investments

Overview

        Our long-term investment philosophy has historically been to maximize our after tax total risk-adjusted return. Under this approach, each dollar of after-tax investment income and realized and unrealized gains and losses is valued equally. In the second half of 2008, we shifted our investment philosophy from a total return focus to a capital preservation focus in response to the significant declines and high volatility in equity markets, the lack of liquidity in the credit markets and the widening of credit spreads on fixed income securities. In particular, we significantly reduced the size of our equity portfolio and now have a larger percentage of our invested assets in cash and short-term

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investments than we have in the past under a total return approach. As overall financial markets and our investment results continue to stabilize, we are gradually shifting back from a focus on capital preservation to our traditional total return investment philosophy.

        Our investment portfolios are managed under agreements with White Mountains Advisors LLC (WM Advisors), a registered investment advisor that is owned by White Mountains, and Prospector Partners, LLC (Prospector), a registered investment advisor. See Note 16—"Related Party Disclosures" of the accompanying consolidated financial statements. Our investment portfolio mix as of December 31, 2009 consisted in large part of high quality, fixed maturity investments and short-term investments, as well as a smaller allocation to equity investments which are comprised of common stock, convertible bonds and other investments such as hedge funds and private equity funds. Our management believes that prudent levels of investments in common equity securities, convertible bonds and other investments within our investment portfolio are likely to enhance long-term after tax total returns without significantly increasing the risk profile of the portfolio.

Fixed Income and Other Investments

        WM Advisors manages our fixed income portfolio, which includes both fixed maturity and short-term investments, and our other investments portfolio. WM Advisors' overall fixed maturity investment strategy is to purchase securities that are attractively priced in relation to credit risks. WM Advisors generally manages the interest rate risk associated with holding fixed maturity investments by actively maintaining the average duration of the portfolio to achieve an adequate after tax total return without subjecting the portfolio to an unreasonable level of interest rate risk.

Common Stock and Convertible Bonds

        Prospector manages our common stock and convertible bond portfolios. Prospector's investment strategy is to maximize absolute total return through investments in a variety of equity, equity-related and convertible bond instruments. Using a value orientation, Prospector invests in relatively concentrated positions in the United States and other developed markets. Prospector's philosophy is to invest for total risk-adjusted return using a bottom-up, value discipline. Preservation of capital is of the utmost importance.

Securities Lending

        We participated in a securities lending program as a mechanism for generating additional investment income on our fixed maturity and common equity portfolios. Under the securities lending arrangements, certain of our fixed maturity and common equity investments were loaned to other institutions for short periods of time through a lending agent. We maintained control over the securities we loaned, retained the earnings and cash flows associated with the loaned securities and received a fee from the borrower for the temporary use of the asset. Collateral, in the form of cash and United States government securities, was required at a rate of 102% of the fair value of the loaned securities. An indemnification agreement with the lending agent protected us in the event a borrower became insolvent or failed to return any of the securities on loan. In the event of a shortfall in the collateral amount required to be returned to the securities lending counterparty (e.g., as a result of investment losses), we were obligated to make up any deficiency.

        Prior to February 2009, the collateral was controlled by the lending agent. The lending agent managed the investment of the cash collateral, however, other than in the event of default by the borrower, this collateral was not available to us and was remitted to the borrower by the lending agent upon the return of the loaned securities. Because of these restrictions, we considered our securities lending activities to be non-cash transactions. The fair value of the securities lending collateral was recorded as both an asset and liability on the balance sheet.

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        In February 2009, we amended the terms of the securities lending program to give us more control over the investment of borrowers' collateral and to separate the assets supporting that collateral into a segregated account. Pursuant to the amendment, (i) the guidelines for the investment of any new cash collateral as well as the reinvestment of cash were narrowed to permit investment in only cash equivalent securities, (ii) we have the authority to direct the lending agent to both sell specific collateral securities in the segregated account and to not sell certain collateral securities which the lending agent proposes to sell, and (iii) we and the lending agent agreed to manage the securities lending program toward an orderly wind-down. In May 2009, we instructed the lending agent not to make any additional loans of securities and to recall all of the securities on loan and fund the return of collateral to the borrower. As of December 31, 2009, $1.7 million in collateral had not been returned to the borrower. As a result of the actions described above, the securities lending assets are no longer segregated and are included within our investment securities.

        At December 31, 2008, prior to the amendment of the terms of the securities lending program, the total market value of our securities on loan was $107.7 million with corresponding collateral of $100.7 million, resulting in an unrealized loss of $7.0 million recorded in change in net unrealized investment gains and losses, a component of net realized and unrealized investment gains (losses). In 2009 prior to exiting the securities lending program, we recorded $3.9 million of net realized and unrealized gains. Subsequent to exiting the program, we recorded $0.8 million of net realized and unrealized gains on the securities returned to us, resulting in a total of $2.3 million of net realized and unrealized losses in connection with our exiting from the program. The securities lending program has generated $18.1 million of additional investment income for us since inception in 2001.

Regulatory Matters

General

        Our insurance operations are subject to regulation and supervision in each of the jurisdictions where they are domiciled and licensed to conduct business. Generally, state regulatory authorities have broad supervisory and administrative powers over such matters as licenses, standards of solvency, premium rates, policy forms, investments, security deposits, methods of accounting, form and content of the consolidated financial statements, reserves for unpaid loss and LAE, reinsurance, minimum capital and surplus requirements, dividends and other distributions to shareholders, periodic examinations and annual and other report filings. In general, such regulation is for the protection of policyholders rather than shareholders.

State Accreditation and Monitoring

        Over the last several years most states have implemented laws that establish standards for current, as well as continued, state accreditation. In addition, the National Association of Insurance Commissioners (NAIC) has adopted risk-based capital (RBC) standards for property and casualty companies, which are designed to determine minimum capital requirements and to raise the level of protection that statutory surplus provides for policyholder obligations. The RBC formula for property and casualty insurance companies measures three major areas of risk facing property and casualty insurers: underwriting, which encompasses the risk of adverse loss developments and inadequate pricing; declines in asset values arising from market and/or credit risk; and off-balance sheet risk arising from adverse experience from non-controlled assets, guarantees for affiliates or other contingent liabilities and excessive premium growth. Under laws adopted by individual states, insurers having less total adjusted capital than that required by the RBC calculation will be subject to varying degrees of regulatory action, depending on the level of capital inadequacy. Our current RBC ratios are satisfactory.

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        The NAIC has developed a set of financial relationships or tests known as the Insurance Regulatory Information System to assist state regulators in monitoring the financial condition of insurance companies and identifying companies that require special attention or action by insurance regulatory authorities. Insurance companies generally submit data annually to the NAIC, which in turn analyzes the data using prescribed financial data ratios, each with defined "usual ranges." Generally, regulators will begin to investigate or monitor an insurance company if its ratios fall outside the usual ranges for four or more of the ratios. If an insurance company has insufficient capital, regulators may act to reduce the amount of insurance it can issue. We are not aware that any of our insurance companies are currently subject to regulatory investigation based on these ratios.

        State insurance laws require us to analyze the adequacy of our reserves annually. Our actuaries must submit an opinion that our reserves, when considered in light of the assets we hold with respect to those reserves, make adequate provision for our contractual obligations and related expenses.

        Effective January 1, 2010, the NAIC adopted amendments to the Annual Financial Reporting Model Regulation, or the Model Audit Rule (MAR). The amendments to the MAR include provisions very similar to Sarbanes-Oxley requirements for public companies and require certain insurance companies to appoint audit committees to oversee accounting and financial reporting processes as well as the audit of the financial statements of the insurer. Audit committees also are required to appoint independent auditors, among other things. The designated audit committee must receive reports regarding significant deficiencies, material weaknesses and solvency concerns at the insurance company level. Certain insurance companies also will be required to file a management report on internal control over financial reporting annually beginning with the fiscal year ending December 31, 2010.

        Many states have laws and regulations that limit an insurer's ability to exit a market. For example, certain states limit a private passenger automobile insurer's ability to cancel or renew policies. Furthermore, certain states prohibit an insurer from withdrawing from one or more lines of insurance business in the state without the state regulator's approval. State regulators may refuse to approve withdrawal plans on the grounds that they could lead to market disruption.

Mandatory Shared Market Mechanisms

        As a condition of our license to do business in certain states, we are required to participate in mandatory shared market mechanisms. Each state dictates the types of insurance and the level of coverage that must be provided. The most common type of shared market mechanism in which we are required to participate is an assigned risk plan. Many states operate assigned risk plans. The NYAIP and New Jersey commercial automobile insurance plans are two such shared market mechanisms in which we are required to participate. These plans require insurers licensed within the applicable state to accept the applications for insurance policies of customers who are unable to obtain insurance in the voluntary market. The total number of such policies an insurer is required to accept is based on its market share of voluntary business in the state. Underwriting results related to assigned risk plans are typically adverse. Accordingly, we may be required to underwrite policies with a higher risk of loss than we would otherwise accept.

        Reinsurance facilities are another type of shared market mechanism. Reinsurance facilities require an insurance company to accept all applications submitted by certain state designated agents. The reinsurance facility then allows the insurer to cede some of its business to the reinsurance facility so that the facility will reimburse the insurer for claims paid on ceded business. Typically, however, reinsurance facilities operate at a deficit, which is funded through assessments against the same insurers. The Massachusetts Commonwealth Automobile Reinsurers is one such reinsurance facility in which we are required to participate.

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Guaranty Associations

        The insurance laws of many states generally provide that property and casualty insurers doing business in those states belong to a statutory property and casualty guaranty association. The purpose of these guaranty associations is to protect policyholders by requiring that solvent property and casualty insurers pay certain insurance claims of insolvent insurers. These guaranty associations generally pay these claims by assessing solvent insurers proportionately based on the insurer's share of voluntary written premiums in the state. While most guaranty associations provide for recovery of assessments through rate increases, surcharges or premium tax credits, there is no assurance that insurers will ultimately recover these assessments. At December 31, 2009, our aggregate reserve for such assessments totaled $17.2 million.

Pricing, Investment and Dividends

        Nearly all states have insurance laws requiring property and casualty insurers to file price schedules, policy or coverage forms, and other information with the state's regulatory authority. In most cases, such price schedules and/or policy forms must be approved prior to use. While pricing laws vary from state to state, their objectives are generally to ensure that prices are adequate, not excessive and not discriminatory. For example, Massachusetts, a state where we have a sizable presence, had previously set virtually all aspects of automobile insurance rates, including agent commissions. While the state has transitioned to a system of managed competition, existing regulations continue to challenge an insurer's ability to adequately price its product, which often leads to unsatisfactory underwriting results.

        We are subject to state laws and regulations that require investment portfolio diversification and that limit the amount of investment in certain categories. Non-compliance may cause non-conforming investments to be non-admitted in measuring statutory surplus and, in some instances, may require divestiture.

        One of the primary sources of cash inflows for us and certain of our intermediary holding companies is dividends received from our operating subsidiaries. Under the insurance laws of the jurisdictions under which our insurance subsidiaries are domiciled, an insurer is restricted with respect to the timing or the amount of dividends it may pay without prior approval by regulatory authorities. During 2009, our first-tier insurance subsidiaries declared and paid $80.0 million in cash and non-cash dividends to OneBeacon Insurance Group LLC (OneBeacon LLC). Our first tier insurance subsidiaries have the ability to pay dividends of approximately $157 million to their parent in 2010 without approval of regulatory authorities.

Holding Company Structure

        We are subject to regulation under certain state insurance holding company acts. These regulations contain reporting requirements relating to our capital structure, ownership, financial condition and general business operations. These regulations also contain special reporting and prior approval requirements with respect to certain transactions among affiliates. Since we are an insurance holding company, the domiciliary states of our insurance subsidiaries impose regulatory application and approval requirements on acquisitions of common shares which may be deemed to confer control over those subsidiaries, as that concept is defined under the applicable state laws. Acquisition of as little as 10% of our common shares may be deemed to confer control under the insurance laws of some jurisdictions, and the application process for approval can be extensive and time consuming.

Terrorism

        While the federal government does not directly regulate the insurance business, federal legislation and administrative policies affect the insurance industry. The Terrorism Act established a federal

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"backstop" for commercial property and casualty losses, including workers compensation, resulting from acts of terrorism by or on behalf of any foreign person or foreign interest. As extended in December 2007, the law also covers domestic acts of terrorism. See "Business—Reinsurance Protection and Catastrophe Management" and "—Terrorism". We are actively complying with the requirements of the Terrorism Act in order to ensure our ability to be reimbursed by the federal government for any losses we may incur as a result of future terrorist acts.

Legislation

        In addition, legislation has been introduced in recent years that, if enacted, could result in the state and federal government assuming a more direct role in the regulation of the insurance industry. Furthermore, a number of additional enacted and pending state and Federal legislative measures could lead to increased consolidation and increased competition for business and capital in the financial services industry. We cannot predict whether any state or Federal measures will be adopted to change the nature or scope of the regulation of the insurance business or what effect such measures may have on our insurance operations.

Environmental

        Both federal and state laws and regulations govern the environmental cleanup of contaminated sites by, or for the account of, potentially responsible parties (PRPs). Superfund and comparable state statutes can impose liability for the entire cost of clean-up upon any responsible party, regardless of fault. The insurance industry in general is involved in extensive litigation regarding coverage issues arising out of the cleanup of such sites by insured PRPs and as a result has disputed many such claims. From time to time, comprehensive Superfund reform proposals are introduced in Congress, but none has yet been enacted. At this time, it remains unclear as to whether Superfund reform legislation will be enacted or that any such legislation will provide for a fair, effective and cost-efficient system for settlement of Superfund related claims. The NICO Cover includes coverage for such exposures at our company, however, there can be no assurance that the coverage provided under the NICO Cover will ultimately prove to be adequate for our incurred environmental losses.

Bermuda Law

        We are an exempted company organized under the Companies Act. As a result, we will need to comply with the provisions of the Companies Act regulating the payment of dividends and making of distributions from contributed surplus. A company is prohibited from declaring or paying a dividend, or making a distribution out of contributed surplus, if there are reasonable grounds for believing that:

•

the company is, or would after the payment be, unable to pay its liabilities as they become due; or



•

the realizable value of the company's assets would thereby be less than the aggregate of its liabilities and its issued share capital and share premium accounts.

        Under our bye-laws, each common share is entitled to dividends if, and when, dividends are declared by our board of directors (the Board), subject to any preferred dividend rights of the holders of any preference shares. Issued share capital is the aggregate par value of the company's issued shares, and the share premium account is the aggregate amount paid for issued shares over and above their par value. Share premium accounts may be reduced in certain limited circumstances. In addition, the Companies Act regulates return of capital, reduction of capital and any purchase or redemption of shares by OneBeacon.

        Although we are incorporated in Bermuda, we have been designated as a non-resident of Bermuda for exchange control purposes by the Bermuda Monetary Authority, or the BMA. Pursuant to our

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non-resident status, we may hold any currency other than Bermuda dollars and convert that currency into any other currency, other than Bermuda dollars, without restriction.

        Shares may be offered or sold in Bermuda only in compliance with the provisions of the Investment Business Act 2003 and the Exchange Control Act 1972, and related regulations of Bermuda which regulate the sale of securities in Bermuda. In addition, specific permission is required from the BMA pursuant to the provisions of the Exchange Control Act 1972 and related regulations, for all issuances and transfers of securities of Bermuda companies, other than in cases where the BMA has granted a general permission. The BMA in its policy dated June 1, 2005 provides that where any equity securities, including our common shares, of a Bermuda company are listed on an appointed stock exchange, general permission is given for the issue and subsequent transfer of any securities of a company from and/or to a non-resident, for as long as any equity securities of such company remain so listed. The New York Stock Exchange is deemed to be an appointed stock exchange under Bermuda law. Notwithstanding the above general permission, the BMA has granted us permission to, subject to our common shares being listed on an appointed stock exchange, (a) issue and transfer our shares, up to the amount of our authorized capital from time to time, to persons resident and non-resident of Bermuda for exchange control purposes; (b) issue and transfer our options, warrants, depositary receipts, rights, and other securities; and (c) issue and transfer our loan notes and other debt instruments and options, warrants, receipts, rights over loan notes and other debt instruments to persons resident and non-resident of Bermuda for exchange control purposes.

        In accordance with Bermuda law, share certificates are issued only in the names of corporations or individuals. In the case of an applicant acting in a special capacity, for example, as an executor or trustee, certificates may, at the request of the applicant, record the capacity in which the applicant is acting. Notwithstanding the recording of any such special capacity, we are not bound to investigate or incur any responsibility in respect of the proper administration of any such estate or trust. We will take no notice of any trust applicable to any of our common shares whether or not we have notice of such trust.

        Under Bermuda law, exempted companies are companies formed for the purpose of conducting business outside Bermuda from a principal place in Bermuda. As exempted companies, we may not, without the express authorization of the Bermuda legislature or under a license granted by the Bermuda Minister of Finance, participate in various specified business transactions, including:

•

the acquisition or holding of land in Bermuda, except land held by way of lease or tenancy agreement which is required for our business and held for a term not exceeding 50 years, or which is used to provide accommodation or recreational facilities for our officers and employees and held with the consent of the Bermuda Minister of Finance, for a term not exceeding 21 years;



•

the taking of mortgages on land in Bermuda in excess of $50,000;



•

the acquisition of any bonds or debentures secured by any land in Bermuda, other than certain types of Bermuda government or public authority securities; or



•

subject to some exceptions, the carrying on of business of any kind in Bermuda for which we are not licensed in Bermuda.

        Under Bermuda law, non-Bermudians (other than spouses of Bermudians) may not engage in any gainful occupation in Bermuda without an appropriate governmental work permit. Work permits may be granted or extended by the Bermuda government upon showing that, after proper public advertisement in most cases, no Bermudian (or spouse of a Bermudian) is available who meets the minimum standard requirements for the advertised position. The Bermuda government's policy limits the duration of work permits to six years, with certain exemptions for key employees. In addition, exempted companies, such as us, must comply with Bermuda resident representation provisions under the Companies Act which require that a minimum number of offices must be filled by persons who are ordinarily resident in Bermuda. We do not believe that such compliance will result in any material expense to us.

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Competition

        Property and casualty insurance is highly competitive. Our competitors include numerous domestic and international insurers, including regional companies, mutual companies, specialty insurance companies, underwriting agencies and diversified financial services companies, some of which have greater financial and marketing resources. The more significant competitive factors for most insurance products we offer are price, product terms and conditions, agency and broker relationships, and claims service. Our underwriting principles and dedication to independent distribution partners are unlikely to make us the low-cost provider in most markets. While it is often difficult for insurance companies to differentiate their products, we believe that providing superior specialty products to satisfy well-defined market needs, relying on agents and brokers who value our targeted expertise, superior claims service, and disciplined underwriting, we establish our competitive advantage. The continued existence of carriers operating with lower cost structures places ongoing pressure on our pricing and terms and conditions, which may impact our ability to compete.

Ratings

        Insurance companies are evaluated by various rating agencies in order to measure each company's financial strength. Higher ratings generally indicate financial stability and a stronger ability to pay claims. We believe that strong ratings are an important factor in the marketing of insurance products and services to agents and consumers. These financial strength ratings do not refer to our ability to meet non-insurance obligations and are not a recommendation to purchase or discontinue any policy or contract issued by us or to buy, hold, or sell our securities.

        The following table presents the financial strength ratings assigned to our principal insurance operating subsidiaries as of February 25, 2010.

        The 5.875% Senior Notes due 2013 of OBH are currently rated "bbb" (Good, the ninth highest of twenty-two creditworthiness ratings) with a stable outlook by A.M. Best, "BBB" (Adequate, the ninth highest of twenty-two creditworthiness ratings) on watch negative by Standard & Poor's, "Baa2" (Medium Grade, the ninth highest of twenty-one creditworthiness ratings) with a negative outlook by Moody's, and "BBB" (Good, the ninth highest of twenty-three creditworthiness ratings) with a negative outlook by Fitch.

Employees

        As of December 31, 2009, we employed approximately 2,100 persons. We believe that we have satisfactory relations with our employees.

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AVAILABLE INFORMATION

        We are subject to the informational reporting requirements of the Securities Exchange Act of 1934. In accordance therewith, we file reports, proxy statements and other information with the Securities and Exchange Commission (SEC). These documents are available free of charge at www.onebeacon.com as soon as reasonably practicable after such material is electronically filed with or furnished to the SEC. In addition, our Code of Business Conduct as well as the charters of our Board Committees are available free of charge at www.onebeacon.com.

        We will provide to any shareholder, upon request and without charge, copies of these documents (excluding any applicable exhibits unless specifically requested). Written or telephone requests should be directed to Investor Relations, OneBeacon Insurance Group, Ltd., 1 Beacon Lane, Canton, MA 02021, (877) 248-8765. Additionally, all such documents are physically available at our registered office at Clarendon House, 2 Church Street, Hamilton, HM 11 Bermuda.

ITEM 1A.    RISK FACTORS

        The information contained in this report may contain "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. See "FORWARD-LOOKING STATEMENTS" (page 105) for specific important factors that could cause actual results to differ materially from those contained in forward-looking statements. The Company's actual future results and trends may differ materially depending on a variety of factors including, but not limited to, the risks and uncertainties discussed below.

Risks Relating to Our Business

         Our loss reserves may be inadequate to cover our ultimate liability for losses and as a result our financial results could be adversely affected.

        We are required to maintain adequate reserves to cover our estimated ultimate liabilities for loss and LAE. Loss and LAE reserves are typically comprised of (1) case reserves for claims reported and (2) reserves for losses that have occurred but for which claims have not yet been reported, referred to as IBNR reserves, which include a provision for expected future development on case reserves. These reserves are estimates based on actuarial, claims and underwriting assessments of what we believe the settlement and administration of claims will cost based on facts and circumstances then known to us. Because of the uncertainties that surround estimating loss and LAE reserves, we cannot be certain that our reserves are adequate and actual claims and claim expenses paid might exceed our reserves due to the uncertainties that surround estimating loss and LAE reserves. For example, we have a large number of workers compensation permanent disability claims. These claims involve medical payments that will be made far into the future and therefore the impact of medical inflation including increased utilization could have a material adverse impact on the ultimate amount of losses paid.

        We had established gross loss and LAE reserves of $3,934.8 million and $4,294.0 million as of December 31, 2009 and 2008, respectively. For the years ended December 31, 2009, 2008, and 2007, we recorded favorable loss reserve development of $83.4 million, $62.0 million and $48.3 million, respectively, net of reinsurance, related to the re-estimation of previously established reserves.

        If in the future we determine that our reserves are insufficient to cover our actual loss and LAE, we would have to strengthen our reserves, which could have a material adverse effect on our financial condition and results of operations.

        For additional information relating to loss and LAE reserve requirements, see "Regulatory Matters." For further discussion of our loss and LAE reserves, including our A&E reserves, see "Business—Loss and LAE Reserves" and "Management's Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Estimates."

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         Exposure to asbestos or environmental claims could materially adversely affect our financial condition and results of operations.

        Estimating our exposure to A&E claims is subject to a particularly high degree of uncertainty. If we have not established adequate loss and LAE reserves to cover future claims, our financial condition and results of operations could be materially adversely affected.

        To help protect against potential A&E claims relating to the period prior to 2001, we have a reinsurance contract from NICO, rated "AA+" (Very Strong, the second highest of twenty-one financial strength ratings) by Standard & Poor's and "A++" (Superior, the highest of fifteen financial strength ratings) by A.M. Best. We refer to this reinsurance contract as the NICO Cover. Under the NICO Cover we are entitled to recover up to $2.5 billion from NICO for (1) all asbestos claims arising from business written by us in 1992 and prior, (2) all environmental claims arising from business written by us in 1987 and prior, and (3) certain other latent exposures. In September 2008, we completed a study of our A&E exposures. Based on the study, we increased our best estimate of incurred losses ceded to NICO, net of underlying reinsurance, by $83.4 million to $2.2 billion. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Insurance Operations—Year ended December 31, 2008 versus year ended December 31, 2007—Asbestos and Environmental Exposures". As of December 31, 2009, we have ceded estimated incurred losses of approximately $2.2 billion to the NICO Cover, leaving remaining protection under the NICO Cover of $320.2 million. Net losses paid totaled $1.2 billion as of December 31, 2009, with $118.0 million paid in 2009. Due to exclusions in policy language and changes in coverages provided, we do not believe that we have significant exposure to asbestos claims arising from business we wrote after 1992 or to environmental claims arising from business we wrote after 1987.

        As of December 31, 2009, we had established gross loss and LAE reserves for asbestos claims of $985.6 million. Approximately 99% of these loss and LAE reserves are covered under reinsurance arrangements. Our net loss and LAE reserves for asbestos claims after giving effect to third party reinsurance other than the NICO Cover was $688.8 million at December 31, 2009. Our net loss and LAE reserves for asbestos claims after giving effect to both third party reinsurance and the NICO Cover was $6.5 million at December 31, 2009.

        Estimating our future exposure to asbestos claims is subject to considerable uncertainty due to tort liability reform in various states, the difficulty of predicting jury awards in such matters and diverging legal interpretations and rules in different jurisdictions. These uncertainties also include, among other things:

•

the extent of coverage under insurance policies;



•

whether or not particular claims are subject to an aggregate limit;



•

the number of occurrences involved in particular claims; and



•

new theories of insured and insurer liability.

        The ultimate liability for our asbestos claims remains uncertain and could exceed the coverage under our reinsurance arrangements and our net loss and LAE reserves.

        Insurers, including us, experienced an increase in the number of new asbestos-related claims in recent years, in particular in 2002 and 2003. We experienced a 12% increase in the number of accounts with asbestos-related claims reported during 2002 as compared to 2001 and another 51% increase in the number reported in 2003 from the level reported in 2002. We believe this increase was attributable to, among other things, more intensive advertising by lawyers seeking asbestos claimants, the increasing focus by plaintiffs on new and previously peripheral defendants, an acceleration of claims prior to the potential enactment of U.S. federal asbestos legislation, and an increase in the number of entities seeking bankruptcy protection as a result of asbestos-related liabilities. During 2004, we started to

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experience a decrease in the number of accounts with asbestos-related claims reported with a 37% decrease from the level reported in 2003; however, the number of accounts with asbestos-related claims reported in 2004 was still above levels reported in 1999, 2000 and 2001. During 2005, 2006, 2007 and 2008, we experienced a 6%, 13%, 15% and 32% decrease, respectively, in the number of accounts with asbestos-related claims reported when compared to the average of the prior three-year period. During 2009, we experienced a 8% decrease in the number of accounts with asbestos-related claims reported when compared to the average of the prior three-year period. It is uncertain whether the number of new annual claims and filings will continue to decrease, remain stable or increase when compared to prior annual periods. Also, in addition to adding new claims, bankruptcy proceedings may have the effect of significantly accelerating and increasing loss payments by insurers, including us.

        Increasingly, policyholders have been asserting that their claims for asbestos-related insurance are not subject to aggregate limits on coverage and that each individual bodily injury claim should be treated as a separate occurrence under a policy. Some policyholders who previously sought payment from us for asbestos claims under their products liability coverages, which were subject to aggregate limits, have increasingly sought payment from us for asbestos claims under the premises and operations coverages of their liability policies, which may not be subject to similar aggregate limits. We expect this trend to continue. To the extent either issue is resolved in favor of policyholders, our coverage obligations under the relevant policies would be materially increased and capped only by the applicable per occurrence limits and the number of asbestos bodily injury claims against the policyholders. Claims in these instances may vary significantly and policyholders may seek large amounts, although such claims frequently settle for a fraction of the initial alleged amount. Accordingly, it is difficult to predict the ultimate size of the claims for coverage not subject to aggregate limits.

        From time to time in recent years, the United States Congress has given consideration to legislative proposals that would address various issues connected with asbestos liability. While it is unclear whether any such proposals will be passed into law at any time in the near future, if at all, we cannot predict what impact, if any, such adopted legislation would have on our ultimate asbestos liability or on the NICO Cover.

        As of December 31, 2009, we had established gross loss and LAE reserves for environmental claims of $350.7 million. Approximately 98% of these loss and LAE reserves are covered under reinsurance arrangements. Our net reserves for environmental claims after giving effect to third party reinsurance other than the NICO Cover was $218.6 million at December 31, 2009. Our net loss and LAE reserves for environmental claims after giving effect to both third party reinsurance and the NICO Cover was $7.6 million as of December 31, 2009. Future exposure from environmental claims is uncertain, in part, for reasons similar to those described above for asbestos claims.

        As a result of various state and federal laws and regulations relating to environmental remediation, particularly the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, which is commonly referred to as Superfund, and related damages claims, the insurance industry continues to be involved in litigation involving policy coverage and liability issues. In addition to regulatory pressures, the results of court decisions affecting the industry's coverage positions continue to be inconsistent and have expanded coverage beyond the industry's original expectations. Accordingly, the ultimate liability for environmental costs remains uncertain and could exceed the coverage of our reinsurance arrangements.

         We may not be able to successfully alleviate risk through reinsurance arrangements. Additionally, we may be unable to collect all amounts due from our reinsurers under our existing reinsurance arrangements.

        We attempt to limit our risk of loss through reinsurance arrangements. The availability and cost of reinsurance protection is subject to market conditions, which are outside of our control. In addition, the coverage under our reinsurance contracts may be inadequate to cover our future liabilities. As a

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result, we may not be able to successfully alleviate risk through these arrangements, which could have a material adverse effect on our financial condition and results of operations.

        We are not relieved of our obligations to our policyholders by purchasing reinsurance. Accordingly, we are subject to credit risk with respect to our reinsurance in the event that a reinsurer is unable to pay amounts owed to us as a result of a deterioration in its financial condition. A number of reinsurers in the industry experienced such deterioration in the aftermath of the 2001 terrorist attacks and the active 2005 hurricane season. To mitigate this risk, we annually review and periodically monitor our reinsurers' financial condition and require at the time of purchase of reinsurance that each of our reinsurers holds a rating of at least "A-" (Excellent, the fourth highest of fifteen financial strength ratings) by A.M. Best or the equivalent. While we believe that our reinsurers' financial condition is strong, it is possible that one or more of our reinsurers will be significantly adversely affected by future significant loss events, causing them to be unable to pay amounts owed to us. We also may be unable to recover amounts due under our reinsurance arrangements if our reinsurers choose to withhold payment due to a dispute or other factors beyond our control.

         Unpredictable catastrophic events could adversely affect our financial condition or results of operations.

        We write insurance policies that cover catastrophic events. Our policies cover unpredictable natural and other disasters, such as hurricanes, windstorms, earthquakes, floods, fires, explosions and severe winter weather. In recent years, the frequency of major weather-related catastrophes has increased. Our exposure to catastrophic windstorm damage in the Northeastern United States is the largest single natural catastrophe risk to our business. Some extremely remote modeled catastrophic events, or series of catastrophic events, could be of sufficient size to cause us to become insolvent, which would adversely affect our financial condition and results of operations. We also have significant exposure to a major earthquake in California and windstorm damage in the United States Atlantic Coast (i.e., Massachusetts to Florida) and the United States Gulf Coast region (i.e., Florida to Texas). In addition, we are exposed to losses from terrorist attacks, such as attacks on the United States on September 11, 2001.

        The extent of losses from a catastrophe is a function of both the total amount of insured exposure in the area affected by the event and the severity of the event. Increases in the value and concentrations of insured property, the effects of inflation and changes in cyclical weather patterns may increase the severity of claims from catastrophic events in the future. Claims from catastrophic events could reduce our earnings and cause substantial volatility in our results of operations for any fiscal quarter or year and adversely affect our financial condition. Our ability to write new insurance policies could also be impacted as a result of corresponding reductions in our surplus levels.

        We manage our exposure to catastrophic losses by limiting the aggregate insured value of policies in geographic areas with exposure to catastrophic events, by estimating a probable maximum loss, which we refer to as PML, for many different catastrophe scenarios and by buying reinsurance. To manage and analyze aggregate insured values and PML, we use a variety of tools, including catastrophe modeling software packages. Our estimates of PML are dependent on many variables, including assumptions about the demand surge and storm surge, loss adjustment expenses, insurance-to-value and storm intensity in the aftermath of weather-related catastrophes utilized to model the event and the relationship of the actual event to the modeled event. Accordingly, if our assumptions about these variables are incorrect, the losses we might incur from an actual catastrophe could be materially higher than our expectation of losses generated from modeled catastrophe scenarios, and our financial condition and results of operations could be materially adversely affected. In December 2009, we completed the Commercial Lines Transaction. In February 2010, we announced the Personal Lines Transaction. The closing of the Personal Lines Transaction is subject to regulatory approvals and is expected to close in the second quarter of 2010. The Commercial Lines Transaction will reduce our

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exposure to catastrophic events and our PML over time as policy terms expire during 2010, while the Personal Lines Transaction will reduce our exposure immediately upon closing.

         Future insurance and reinsurance coverage for terrorist acts is uncertain, and we may in the future have substantial exposure to such acts.

        We are unable to predict the extent to which our future insurance contracts will cover terrorist acts. We also are unsure how terrorist acts will be defined in our future contracts. The Terrorism Act, which has been extended through the end of 2014, requires primary commercial insurers to make terrorism coverage available and provides Federal protection for certain losses above both individual company retention and industry retention levels. While we know of no reason that the Terrorism Act will not be extended for an additional period of time, there is no assurance that it will be extended or of the terms of any such extension. The following types of coverage are excluded from the program: commercial automobile, burglary and theft, surety, farmowners, multi-peril and all professional liability coverages except directors and officers coverage. We manage our exposure to losses resulting from acts of terrorism by limiting our concentration of risk by geographic area. We estimate our PML for different scenarios using computer models in conjunction with other data. We also manage our terrorism exposures by purchasing reinsurance. Our current property and casualty catastrophe reinsurance programs provide coverage for us for "non-certified" events as defined under the Terrorism Act, provided such losses are not the result of a nuclear, biological, chemical or radiological terrorist attack. Nonetheless, risks insured by us, including those covered by the Terrorism Act, remain exposed to terrorist attacks and the possibility remains that losses resulting from future terrorist attacks could prove to be material to our results of operations and financial condition.

         Our investment portfolio may suffer reduced returns or losses which could adversely affect our results of operations and financial condition. Any adverse change in interest rates or volatility in the equity or debt markets could result in significant losses in the fair value of our investment portfolio.

        Our investment portfolio consists of fixed maturity securities, convertible bonds, short-term investments, common equity securities and other investments such as hedge funds and private equity funds. Our investment selections are designed to maximize after tax, total risk-adjusted return over the long term; however, investing entails substantial risks. We cannot assure you that we will achieve our investment objectives, and our investment performance may vary substantially over time.

        Investment returns are an important part of our strategy to grow book value, and fluctuations in the fixed income or equity markets could impair our results of operations or financial condition. A significant period of time normally elapses between the receipt of insurance premiums and the disbursement of insurance claims. During this time, we invest our capital and funds allocated to support unpaid loss and LAE reserves. We seek to maximize our total return on these investments through the generation of investment income, consisting primarily of interest earned on fixed maturity investments and dividends earned on equity securities, and realized and unrealized investment gains on the securities we hold in our investment portfolio.

        The investment income and fair market value of our investment portfolio are affected by general economic and market conditions, including fluctuations in interest rates and volatility in the stock market. Interest rates are highly sensitive to many factors, including governmental monetary policies, domestic and international economic and political conditions and other factors beyond our control. Although we attempt to manage the risks of changes in interest rates, we may not be able to do so. In particular, a significant increase in interest rates could result in significant losses, realized or unrealized, in the fair value of our investment portfolio and, consequently, could have an adverse effect on our results of operations and financial condition.

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        In addition, we are exposed to changes in the level or volatility of equity prices that affect the value of securities or instruments that derive their value from a particular equity security, a basket of equity securities or a stock index. These conditions are outside of our control and could adversely affect the value of our investments and our results of operations and financial condition. During 2008, financial markets experienced an unprecedented level of volatility. For the year ended December 31, 2008, we recognized a total pre-tax investment loss of $585.1 million, primarily due to the downturn in the equities markets. Although we have taken steps to reduce the level of risk in our portfolio by reducing our equity holdings, which are comprised of common stock, convertible bonds and other investments, from 19% at December 31, 2008 to 12% at December 31, 2009, there is no assurance that these steps will fully protect us from further market downturns and volatility.

        We are highly dependent on WM Advisors, which is owned by White Mountains, and Prospector, in connection with the management of our investment portfolio. WM Advisors supervises and directs the fixed income and other investments portion of our investment portfolio, and Prospector supervises and directs the publicly-traded common equity securities and convertible bonds portion of our investment portfolio. The investment management agreements with each of WM Advisors and Prospector, entered into in November 2006 in connection with our initial public offering, provided for an initial fixed term of three years, which was extended by us for an additional two year term. If we lose our investment relationship with WM Advisors or with Prospector, we may not be able to secure an investment advisor or advisors who will produce returns on our investments similar to these produced by WM Advisors and Prospector in the past, or any positive returns at all.

         We may not maintain favorable financial strength or creditworthiness ratings, which could adversely affect our ability to conduct business.

        Third party rating agencies assess and rate the financial strength, including claims-paying ability, of insurers and reinsurers. These ratings are based upon criteria established by the rating agencies and are subject to revision at any time at the sole discretion of the agencies. Some of the criteria relate to general economic conditions and other circumstances outside the rated company's control. These financial strength ratings are used by policyholders, agents and brokers as an important means of assessing the suitability of insurers as business counterparties and have become an increasingly important factor in establishing the competitive position of insurance companies. These financial strength ratings do not refer to our ability to meet non-insurance obligations and are not a recommendation to purchase or discontinue any policy or contract issued by us or to buy, hold or sell our securities. General creditworthiness ratings are used by existing or potential investors to assess the likelihood of repayment on a particular debt issue. We believe that strong debt ratings are important factors that provide better financial flexibility when issuing new debt or restructuring existing debt.

        Rating agencies periodically evaluate us to confirm that we continue to meet the criteria of the ratings previously assigned to us. Our current financial strength ratings are "A" (Excellent, third highest of fifteen ratings) by A. M. Best, "A" (Strong, sixth highest of twenty-one ratings) by Standard & Poor's, "A2" (Good, sixth highest of twenty-one ratings) by Moody's and "A" (Strong, sixth highest of twenty-one ratings) by Fitch. We currently have a "Stable" outlook from A.M. Best and as of February 2010 are on "Watch Negative" with Standard & Poor's. In 2009, Fitch changed our outlook from "Stable" to "Negative", and in February 2010, Moody's also changed our outlook from "Stable" to "Negative" after placing our ratings under review for a potential downgrade on December 4, 2009. A downgrade, withdrawal or negative watch/outlook of our financial strength ratings could severely limit or prevent our insurance subsidiaries from writing new insurance policies or renewing existing insurance policies, which could have a material adverse effect on our financial condition and results of operations. A downgrade, withdrawal or negative watch/outlook of our creditworthiness ratings could severely limit our ability to raise new debt or make new debt more costly and/or have more restrictive conditions.

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         Our debt and related service obligations could adversely affect our business.

        As of December 31, 2009, we had $621.1 million face value of indebtedness. Our ability to meet our debt and related service obligations, as well as our ability to pay a dividend on our common shares, will depend on our future performance, which will be affected by financial, business, economic, regulatory and other factors, many of which are beyond our control. In addition, White Mountains is subject to restrictive financial covenants contained in its revolving credit facility that require White Mountains to pay the principal and interest on its debt and maintain specified financial ratios and to satisfy financial condition tests. A breach of these covenants could result in an event of default under White Mountains' revolving credit facility which would allow lenders to declare all amounts owed under the revolving credit facility to be immediately due and payable. A failure to pay principal and interest on White Mountains' revolving credit facility would trigger cross acceleration provisions contained in the indentures of our Senior Notes. We cannot be certain that our earnings will be sufficient to allow us to pay the principal and interest on our debt and meet our other obligations, or to repay any accelerated indebtedness as a result of the trigger of the cross acceleration provisions in the indentures of the Senior Notes. If we do not have enough cash, we may be required to refinance all or part of our existing debt, sell assets, borrow more cash or sell equity. We cannot assure you that we will be able to accomplish any of these alternatives on terms acceptable to us, if at all. See the risk factor concerning our Senior Notes, "Management's Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources—Financing" and Note 16—"Related Party Disclosures" of the accompanying consolidated financial statements.

        We could incur additional indebtedness and issue preferred stock in the future. To the extent new debt, preferred stock and other obligations are added to our and our subsidiaries' current debt levels, the risks described in the previous paragraph would increase.

         We are a holding company with no direct operations, and our insurance subsidiaries' ability to pay dividends to us is restricted by law.

        As a holding company with no direct operations, we rely on net investment income and dividends and other permitted payments from our subsidiaries to pay our expenses. Our subsidiaries may not be able to generate cash flow sufficient to pay a dividend or distribute funds to us. In addition, under the insurance laws of the jurisdictions in which our insurance subsidiaries are domiciled, an insurer is restricted with respect to the timing or the amount of dividends it may pay without prior approval by regulatory authorities. Generally, our regulated operating subsidiaries have the ability to pay dividends during any 12-month period in an amount equal to the greater of prior year statutory net income or 10% of prior year statutory surplus, subject to the availability of unassigned funds. As a result, based on 2009 statutory surplus, our top tier regulated operating subsidiaries have the ability to pay approximately $157 million of dividends during 2010, subject to the availability of unassigned funds. As of December 31, 2009, our top tier regulated operating subsidiaries had $1.1 billion of unassigned funds available for dividend distribution. Management believes that our cash balances, cash flows from operations and cash flows from investments are adequate to meet expected cash requirements for the foreseeable future on both a holding company and operating subsidiary level. However, if our insurance subsidiaries cannot pay dividends in future periods, we may have difficulty servicing our debt, paying dividends on our common shares and meeting our holding company expenses. For additional information relating to insurance regulations governing our operations, see "Regulatory Matters."

         The property and casualty insurance industry is highly competitive and we may not be able to compete effectively in the future.

        The property and casualty insurance industry is highly competitive and has historically been cyclical, experiencing periods of severe price competition and less selective underwriting standards (soft markets) followed by periods of relatively high prices and more selective underwriting standards (hard

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markets). We compete with numerous domestic and international insurance companies. Many of our competitors have greater financial, marketing and management resources than we do and have established long-term and continuing business relationships throughout the insurance industry, which can be a significant competitive advantage for them.

        In addition, we predominantly offer our products through a network of independent agents and brokers. These agents and brokers are sometimes able to offer substantial discounts in pricing through their other markets as compared to our insurance products. If our distribution partners experience increased competition from other writers of insurance, we in turn could be adversely affected if they are unable to maintain our competitive position in their respective markets. If we are unable to maintain our competitive position throughout soft and hard market cycles, our financial condition and results of operations may be adversely affected.

         We may suffer losses from unfavorable outcomes from litigation and other legal proceedings.

        In the ordinary course of business, we are subject to litigation and other legal proceedings as part of the claims process, the outcomes of which are uncertain. We maintain reserves for these legal proceedings as part of our loss and LAE reserves. We also maintain separate reserves for legal proceedings that are not related to the claims process. In the event of an unfavorable outcome in one or more legal matters, our ultimate liability may be in excess of amounts we have currently reserved for and such additional amounts may be material to our results of operations and financial condition. As of December 31, 2009, we had no material pending legal proceedings.

        As industry practices and legal, judicial, social and other conditions change, unexpected and unintended issues related to claims and coverage may emerge. These issues may adversely affect our financial condition and results of operations by either extending coverage beyond our underwriting intent or by increasing the number and size of claims. In some instances, these changes may not become apparent until some time after we have issued insurance contracts that are affected by the changes.

         Our profitability may be adversely impacted by inflation, legislative actions and judicial decisions.

        The effects of inflation could cause claim costs to rise in the future. In addition, legislative actions and judicial decisions continue to broaden liability and policy definitions and to increase the severity of claim payments, such as described above with respect to A&E claims. To the extent inflation and these legislative actions and judicial decisions cause claim costs to increase above reserves established for these claims, we will be required to increase our loss and LAE reserves with a corresponding reduction in our net income in the period in which the deficiency is identified.

         Regulation may restrict our ability to operate.

        The insurance industry is subject to extensive regulation under U.S. and state laws. Governmental agencies have broad administrative power to regulate many aspects of the insurance business, which include premium rates, marketing practices, advertising, policy forms and capital adequacy. These governmental agencies are concerned primarily with the protection of policyholders rather than shareholders. Insurance laws and regulations impose restrictions on the amount and type of investments, prescribe solvency standards that must be met and maintained and require the maintenance of reserves. Premium rate regulation is common across all of our lines of business and may make it difficult for us to increase premiums to adequately reflect the cost of providing insurance coverage to our policyholders. In our underwriting, we rely heavily upon information gathered from third parties such as credit report agencies and other data aggregators. The use of this information is also highly regulated and any changes to the current regulatory structure could materially affect how we underwrite and price premiums.

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        Changes in laws and regulations may restrict our ability to operate and/or have an adverse effect upon the profitability of our business within a given jurisdiction. For example, there are efforts currently underway to federally regulate financial services companies, which could include insurance companies, including through the establishment of a federal regulatory body or agency. This legislation, if enacted, could result in the Federal government assuming a more direct role in the regulation of the insurance industry. The current U.S. Congress could address the issue of Federal regulation of insurance companies, including issues such as Federal preemption of state insurance regulations as well as solvency and capital requirements. We cannot predict whether any Federal legislation will be enacted at all, or if it is enacted, what issues it will address. Any such legislation could have an effect on our business, results of operations and financial condition.

         We may be unable to collect amounts utilized to capitalize reciprocals.

        Since 2002, we have capitalized three member-owned, not-for-profit insurance associations, which we refer to as reciprocals, by loaning money to them in exchange for surplus notes. As of December 31, 2009, we have loaned an aggregate of $125.9 million, including $0.2 million loaned in the form of a security deposit, to the three reciprocals, and accrued $62.9 million in interest. These three associations are currently consolidated in our financial statements. As a result, the surplus notes, the security deposit and accrued interest have been eliminated in consolidation. In the future, depending on their financial success, these associations could be deconsolidated. At such time, the surplus notes would be reflected as notes receivable on our balance sheet. Amounts utilized to capitalize reciprocals can be difficult to extract as repayment of principal and interest is subject to regulatory approval. If any reciprocal is unable to cover its ultimate liability for loss and LAE or is unable to obtain insurance regulatory approval to repay us, we would be unable to collect amounts owed under the related surplus note. In addition, while we have no legal obligation to loan further funds to these reciprocals, even in the event their capital becomes depleted, we may decide that it is in our best interest to provide the reciprocal with additional capital, thereby increasing our loss exposure. In November 2009, based upon the availability of surplus and unassigned funds, we submitted an application to the New York State Insurance Department to enable us to commence repayment of the Adirondack Insurance surplus note. As of the date hereof, we have not received approval to commence repayment. In February 2010, we announced the Personal Lines Transaction. The closing of the Personal Lines Transaction is subject to regulatory approval and is expected to close in the second quarter of 2010. As part of the Personal Lines Transaction, we agreed to sell the surplus notes. As consideration for the Personal Lines Transaction, we will receive an amount equal to the statutory surplus in the reciprocals, including the par value of the surplus notes issued by the reciprocals to us, the GAAP equity in the insurance companies and attorneys-in-fact, plus $32.5 million.

         We depend on our key personnel to manage our business effectively and they may be difficult to replace.

        Our performance substantially depends on the efforts and abilities of our management team and other executive officers and key employees. Furthermore, much of our competitive advantage is based on the expertise, experience and know-how of our key management personnel. We do not have fixed term employment agreements with any of our key employees nor key man life insurance, and the loss of one or more of these key employees could adversely affect our business, results of operations and financial condition. Our success also depends on the ability to hire and retain additional key personnel. Difficulty in hiring or retaining key personnel could adversely affect our results of operation and financial condition.

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         Our written premiums are heavily concentrated in the Northeastern United States.

        Our revenues and profitability for the foreseeable future will be substantially impacted by prevailing regulatory, economic, demographic, competitive, weather and other conditions in the Northeastern United States. Changes in any of these conditions could make it more costly or more difficult to conduct our business. We are particularly exposed to Northeast windstorm risks. In 2009, 49.3% of our direct written premiums were derived from our Insurance Operations in New York, Massachusetts, New Jersey, Maine and Connecticut. In February 2010, we announced the Personal Lines Transaction. The closing of the Personal Lines Transaction is subject to regulatory approvals and is expected to close in the second quarter of 2010. The Personal Lines Transaction will significantly reduce our exposure to Northeast windstorm risks and premium concentration in the Northeastern United States.

         Mandated market mechanisms may require us to underwrite policies with a higher risk of loss and assessments and other surcharges for guaranty funds and second-injury funds may reduce our profitability.

        We are often required to participate directly or indirectly in mandatory shared market mechanisms as a condition of our licenses to do business in certain states. These markets, which are commonly referred to as "residual" or "involuntary" markets, generally consist of risks considered to be undesirable from a standard or routine underwriting perspective. In 2009, approximately 1% of our net written premiums, excluding premiums written by AutoOne, related to our participation in mandatory shared market mechanisms. Underwriting performance related to assigned risk plans, a form of mandated market mechanism, is typically adverse and, as a result, we are required to underwrite some policies with a higher risk of loss than we would normally accept.

        Each state dictates the level of insurance coverage that is mandatorily assigned to participating insurers within these markets. Our participation in mandatory shared market mechanisms is principally concentrated in the States of Massachusetts, New Jersey and New York. In certain states, such as New York, the amount of involuntary policies we are obligated to write in a given year is based on our historical market share of all voluntary policies written within that state. The share of involuntary written premium for policies assigned by the NYAIP, a residual insurance plan that obtains personal automobile insurance for individuals who cannot otherwise obtain insurance in the voluntary insurance market, to a particular insurer in a given year is based on the proportion of the total voluntary writings in New York two years earlier. We estimate the cost of discharging our obligation for our NYAIP assignments as of December 31, 2009 to be $5.9 million and we have recorded this estimate as a liability in our consolidated financial statements. Our participation in assigned risk plans may result in greater liabilities than we anticipate and could materially adversely affect our financial condition and results of operations.

        In addition, virtually all states require insurers licensed to do business in their state to bear a portion of the loss suffered by some insureds as the result of impaired or insolvent insurance companies. These guaranty funds are funded by assessments that are expected to increase in the future as a result of recent insolvencies. Many states also have laws that established second-injury funds to provide compensation to injured employees for aggravation of a prior condition or injury which are funded by either assessments based on paid losses or premium surcharge mechanisms. The effect of these assessments and surcharges or changes in them could reduce our profitability in any given period or limit our ability to grow our business.

         Cyclicality of the property and casualty insurance industry may cause fluctuations in our results of operations and financial condition.

        The property and casualty insurance business historically has been characterized by periods of intense price competition, which could have an adverse effect on our results of operations and financial

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condition. Periods of intense price competition historically have alternated with periods when shortages of underwriting capacity have permitted attractive premium levels. Any significant decrease in the rates we can charge for property and casualty insurance would adversely affect our results.

        Our personal lines business is particularly affected by the cyclicality of loss cost trends. Factors that affect loss cost trends in automobile underwriting include inflation in the cost of automobile repairs, medical care, litigation of liability claims, improved automobile safety features, legislative changes and general economic conditions. Factors that affect loss cost trends in homeowners underwriting include inflation in the cost of building materials and labor costs and demand caused by weather-related catastrophes. Personal lines insurers, including us, are generally unable to increase premium rates until some time after the costs associated with the coverage have increased, primarily as a result of state insurance regulation laws. Therefore, in a period of increasing loss costs, profit margins decline.

        We expect to continue to experience the effects of this cyclicality which, during down periods, could materially adversely affect our financial condition and results of operations.

         The failure to close the Personal Lines Transaction could result in a loss of premium revenue and adversely impact our business and results of operations.

        We announced the Personal Lines Transaction with Tower on February 2, 2010. The closing of the Personal Lines Transaction is subject to certain regulatory approvals and is expected to close in the second quarter of 2010. While we anticipate that the Personal Lines Transaction will close as scheduled, there can be no assurance that we or Tower will receive the required regulatory approvals or otherwise be able to close the transaction timely or at all. Because we market our personal lines business through a network of independent agents, we risk a loss of business from these agents if we are unable to close the Personal Lines Transaction for any reason. Other insurance companies compete with us for the services and allegiance of these agents. These producers may choose to direct business to our competitors, or may direct less desirable risks to us. The loss of one or more agents and/or business from agents could adversely impact our premium volume, resulting in a decrease in our revenues, and our business, results of operations and financial condition could be materially and adversely affected.

         We may need additional capital in the future, which may not be available to us or available to us on favorable terms. Raising additional capital could dilute your ownership in our company and may cause the market price of our common shares to fall.

        We may need to raise additional funds through public or private debt or equity financings in order to:

•

fund liquidity needs;



•

replace capital lost in the event of a catastrophe or adverse reserve development or investment losses;



•

refinance $607.1 million aggregate principal amount of our Senior Notes;



•

satisfy letter of credit or guarantee bond requirements that may be imposed by our clients or by regulators;



•

acquire new businesses or invest in existing businesses;



•

expand our business into new regions and countries; or



•

otherwise respond to competitive pressures.

        Any additional capital raised through the sale of equity will dilute your ownership percentage in our company and may decrease the market price of our common shares. Furthermore, the securities may have rights, preferences and privileges that are senior or otherwise superior to those of our

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common shares. Any additional financing we may need may not be available on terms favorable to us, or at all.

         We may be unable to adequately maintain our systems and safeguard the security of our data which may adversely impact our ability to operate our business and cause reputational harm and financial loss.

        Our business and operations rely on secure and efficient processing, storage and transmission of customer and company data, including personally identifiable information such as a name together with a social security number, bank account number, driver's license number, passport number or birthday (PII). Our ability to effectively operate our business depends upon our ability and the ability of certain third parties including vendors and business partners to access our computer systems to perform necessary business functions such as providing quotes and product pricing, billing and processing premiums, administering claims, and reporting our financial results. Our business and operations also depend upon our ability to safeguard PII and other confidential and proprietary information belonging to us and our policyholders. Our systems may be vulnerable to unauthorized access and hackers, computer viruses, and other scenarios in which our data may be vulnerable to a breach. Specifically, we could be exposed to data breach risk from lost or stolen laptops, other portable media or misdirected mailings containing PII.

        Data incidents could result in reputational harm to us, which could affect our business and results of operations. Nearly every state has enacted data breach laws and regulations that require, among other things, notification to affected persons and state regulatory agencies of a data breach that involves PII. Some U.S. state and federal laws also require us to implement measures to safeguard PII. For example, new Massachusetts regulations will require our employees to encrypt information stored on laptops and other portable devices and transmitted through electronic media, and take reasonable steps to verify that our third party vendors utilize security procedures to protect PII.

        We have taken a number of steps to mitigate our risk. We have formed a Data Privacy Committee and appointed an Information Privacy and Security Officer. We have implemented policies, procedures, training and education of employees, as well as technology solutions to safeguard our information. Although we have taken measures to safeguard our information and that of policyholders and other third parties, and we continually monitor the security of our systems and information, we could be exposed to data loss. As a result, our ability to conduct our business may be affected, and impact our results of operations, financial condition and reputation.

Risks Relating to Our Relationship with White Mountains

         Control of us by White Mountains and the holding of White Mountains shares by some of our directors and officers may result in conflicts of interest.

        White Mountains beneficially owns all of our Class B common shares, representing 96.8% of the voting power of our voting securities and 75.4% of our total equity as of December 31, 2009. As long as White Mountains owns our common shares representing more than 50% of the voting power of our outstanding voting securities, White Mountains will generally be able to determine the outcome of all corporate actions requiring shareholder approval, including the election of directors. Furthermore, we are relying on the "controlled company" exemption under the rules of the New York Stock Exchange, and are therefore not required to have a majority of independent directors on our Board. Of the eleven directors that we have on our Board, seven are current or former employees, directors or officers of White Mountains. White Mountains also has control over the adoption or amendment of provisions in our memorandum of association or bye-laws and the approval of amalgamations, mergers, and other significant corporate transactions. Furthermore, White Mountains will continue to be able to exercise this control as long as their economic equity ownership in us is at least 20%. These factors also may delay or prevent a change in the management or voting control of us.

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        Also, at some time in the future, White Mountains may sell all or a portion of its ownership interest in us or may make a tax-free distribution to its shareholders of all or a portion of that interest.

        Questions relating to conflicts of interest may arise between us and White Mountains in a number of areas relating to our past and ongoing relationships. Certain of our directors and a number of our executive officers may own substantial amounts of White Mountains stock and may also be directors or officers of White Mountains from time to time. Their ownership of White Mountains stock and these other relationships could create, or appear to create, potential conflicts of interest when these individuals are faced with decisions that could have different implications for us and White Mountains. These potential conflicts could arise, for example, over matters such as the desirability of an acquisition opportunity, employee retention or recruiting, or our dividend policy.

         White Mountains may compete with us and the involvement of those individuals who are directors and officers of White Mountains and directors of ours in resolving matters relating to such competition will not constitute a breach of fiduciary duty to us.

        Our bye-laws provide that White Mountains will have no obligation to refrain from:

•

engaging in the same or similar business activities or lines of business as we do; or



•

doing business with any of our clients or customers.

        Because White Mountains may currently or in the future engage in the same activities in which we engage, we may be in direct competition with White Mountains. While White Mountains has indicated to us that its current expectation is to manage its activities such that opportunities to acquire specialty businesses will be pursued through OneBeacon, White Mountains is not legally obligated to do so and could in the future manage its activities in a different way. Due to the resources of White Mountains, including financial resources, name recognition and knowledge of our strengths, weaknesses and business practices, White Mountains could have a competitive advantage over us should it decide to engage in the type of business we conduct, which may have a material adverse effect on our operations and financial condition. The corporate opportunity policy included in our bye-laws addresses potential conflicts of interest between us, on the one hand, and White Mountains and its officers and directors who are also our directors, on the other hand. These provisions are designed to resolve conflicts between us and White Mountains. Under our bye-laws, it is not a breach of fiduciary duty on the part of any of our officers and directors by reason of their participation in any of the above described activities.

         Transitional and other arrangements with White Mountains may not be on arm's length terms.

        In connection with the initial public offering, we entered into certain contractual arrangements with White Mountains and its affiliates. These agreements were made in the context of a parent-subsidiary relationship. For example, some of our investments are managed pursuant to an investment management agreement on a discretionary basis by a registered investment advisor which is owned by White Mountains. We have a multi-year investment management contract with this advisor. While we are satisfied with the terms of such arrangement, we cannot confirm that such terms are as favorable to us as they might have been had we contracted with an independent advisor. On the other hand, after the expiration of this agreement, we may not be able to replace these investment services in a timely manner or on terms and conditions, including cost, that are comparable to those we receive from White Mountains, and we may have to pay higher prices for similar services from unaffiliated third parties. For more information on these and other arrangements with White Mountains, see Note 16—"Related Party Disclosures" of the accompanying consolidated financial statements.

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         Refinancing of our Senior Notes may occur on unfavorable terms.

        In connection with the initial public offering, we entered into an agreement with White Mountains pursuant to which White Mountains guarantees the Senior Notes of our subsidiary, OBH, for a specified fee in the amount of 25 basis points per annum on the outstanding principal amount of the Senior Notes. We further agreed that if White Mountains' voting interest in our common shares ceases to represent more than 50% of all our voting securities, we will seek to redeem, exchange or otherwise modify the Senior Notes in order to fully and permanently eliminate White Mountains' obligations under its guarantee. White Mountains and its subsidiaries beneficially own all of our outstanding Class B common shares, representing 96.8% of the voting power of our voting securities. If we have not successfully eliminated the guarantee within 180 days upon notice of the triggering of the voting interest condition, the guarantee fee will increase by 200 basis points. The guarantee fee will further increase by 100 basis points for each subsequent 90 day period thereafter, up to a maximum guarantee fee of 425 basis points, until White Mountains' obligations under its guarantee have been extinguished. This arrangement could require us to devote significant time and expense trying to refinance the Senior Notes and we may not be able to do so on commercially reasonable terms or at all.

        White Mountains has two revolving credit facilities which provide for borrowing up to a maximum of $450.8 million and which contain restrictive financial covenants. The indenture documents governing the Senior Notes provide that if White Mountains as guarantor of the Senior Notes has a payment default in excess of $25 million under a credit agreement, mortgage or similar debt agreement, there is a default under the Senior Notes (commonly referred to as a "cross default"). Therefore, if White Mountains were to breach one or more of its financial covenants in its revolving credit facilities, an event of default would result, which would allow lenders to declare all amounts owed under the revolving credit facilities to be immediately due and payable. A failure to pay the amounts owed under the revolving credit facilities would result in a trigger of the cross default provisions in the indenture documents governing the Senior Notes resulting in a required repayment of the Senior Notes. While we believe that White Mountains is able to meet its obligations under its revolving credit facilities, there is the potential that adverse market or other conditions which cannot be controlled could adversely impact White Mountains' ability to meet its obligations as well as our ability to refinance the Senior Notes in the event of a cross default. As of December 31, 2009, the credit facilities were undrawn. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources—Financing" and Note 16—"Related Party Disclosures" of the accompanying consolidated financial statements.

Risks That Relate to Taxes

         We may become subject to taxes in Bermuda after 2016.

        We have received a standard assurance from the Bermuda Minister of Finance, under Bermuda's Exempted Undertakings Tax Protection Act 1966, that if any legislation is enacted in Bermuda that would impose tax computed on profits or income, or computed on any capital asset, gain or appreciation, or any tax in the nature of estate duty or inheritance tax, then the imposition of any such tax will not be applicable to us or to any of our operations or our shares, debentures or other obligations until March 28, 2016. Given the limited duration of the Minister of Finance's assurance, we cannot be certain that we will not be subject to any Bermuda tax after March 28, 2016. In the event that we become subject to any Bermuda tax after such date, it could have a material adverse effect on our financial condition and results of operations.

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         Changes in tax laws or tax treaties may cause more of the income of certain non-U.S. companies in our group to become subject to taxes in the United States.

        The taxable income of our U.S. subsidiaries is subject to U.S. federal, state and local income tax and other taxes. The income of the non-U.S. companies in our group is generally not subject to tax in the United States other than withholding taxes on interest and dividends. Certain of our non-U.S. companies are eligible for the benefits of tax treaties between the United States and other countries. We believe our non-U.S. companies will continue to be eligible for treaty benefits. However, it is possible that factual changes or changes to U.S. tax laws or changes to tax treaties that presently apply to our non-U.S. companies could impact income subject to tax in the United States. Similarly, changes to the applicable tax laws, treaties or regulations of other countries could subject the income of members of our group to higher rates of tax outside the United States.

ITEM 1B.    UNRESOLVED STAFF COMMENTS

        As of the date of this report, we had no unresolved written comments from the Commission staff regarding our periodic or current reports under the Exchange Act.

ITEM 2.    PROPERTIES

        Our headquarters are located at 14 Wesley Street, 5th Floor, Hamilton HM 11, Bermuda. Our U.S. headquarters are located at 1 Beacon Lane, Canton, Massachusetts 02021, our principal executive office is located at 601 Carlson Parkway, Minnetonka, Minnesota 55305 and our registered office is located at Clarendon House, 2 Church Street, Hamilton HM 11, Bermuda. We also maintain branch offices in various cities throughout the United States. Our U.S. headquarters is owned by us. Our headquarters, principal executive office and our branch offices are leased. Management considers our office facilities suitable and adequate for our current level of operations.

ITEM 3.    LEGAL PROCEEDINGS

        The Company from time to time is involved in various routine legal proceedings. We believe that the outcome of these proceedings, even if determined adversely, would not have a material adverse effect on our business, financial condition and results of operations.

ITEM 4.    SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

        There were no matters submitted to a vote of our shareholders during the fourth quarter of 2009.

Executive Officers of the Registrant and its Subsidiaries as of February 26, 2010:

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