OMB APPROVAL OMB Number: 3235-0116 Expires: March 31, 2003 Estimated average burden hours per response: 8 Form 6-K SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Report of Foreign Private Issuer Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934 For the month of December, 2006 CONVERIUM HOLDING AG -------------------- (Translation of registrant's name into English) Dammstrasse 19 CH-6301 Zug Switzerland ----------- (Address of principal executive offices) Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F. Form 20-F X Form 40-F --- --- Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934. Yes No X --- --- If "Yes" is marked, indicate the file number assigned to the registrant in connection with Rule 12g3-2(b): 82- Not Applicable Converium Holding Ltd, Zug Zug, Switzerland - December 14, 2006 - Converium closes the sale of its North American operations. Following the receipt of all necessary regulatory approvals Converium today announces the closing of the sale of its North American operations to National Indemnity Company, a Berkshire Hathaway company. The transaction, which was announced on October 17, 2006, will be reflected in Converium's 4Q 2006 financial statements. Inga Beale, CEO of Converium, said: "With today's announcement we have achieved finality on our North American operations. The closing of the transaction meets a major condition for a ratings upgrade by Standard & Poor's." Converium has made it a policy not to provide any quarterly or annual earnings guidance and it will not update any past outlooks for full-year earnings. It will, however, continue to provide investors with perspectives on its value drivers, certain financial guidance for the full year, its strategic initiatives and those factors critical to understanding its business and operating environment. Enquiries Beat W. Werder Marco Circelli Dr. Kai-Uwe Schanz Head of Public Relations Head of Investor Relations Chief Communication & Corporate Development Officer beat.werder@converium.com marco.circelli@converium.com kai-uwe.schanz@converium.com Phone: +41 (0) 44 639 90 22 Phone: +41 (0) 44 639 91 31 Phone: +41 (0) 44 639 90 35 Fax: +41 (0) 44 639 70 22 Fax: +41 (0) 44 639 71 31 Fax: +41 (0) 44 639 70 35 About Converium Converium is an independent international multi-line reinsurer known for its innovation, professionalism and service. Today Converium employs about 500 people in 15 offices around the globe and is organized into three business segments: Standard Property & Casualty Reinsurance, Specialty Lines and Life & Health Reinsurance. Converium has a "BBB+" financial strength rating (Credit Watch positive) from Standard & Poor's and a "B++" financial strength rating (outlook positive) from A.M. Best Company. Important Disclaimer This document contains forward-looking statements as defined in the U.S. Private Securities Litigation Reform Act of 1995. It contains forward-looking statements and information relating to the Company's financial condition, results of operations, business, strategy and plans, based on currently available information. These statements are often, but not always, made through the use of words or phrases such as `seek to', `expects', `should continue', `believes', `anticipates', `estimates' and `intends'. The specific forward-looking statements cover, among other matters, the Company's internal review and related restatement, the reinsurance market, the Company's operating results, certain financial guidance, e.g. related to the tax rate of the Company, the reduction of North American net reserves, the acquisition costs ratio and the costs of the Corporate Center, the rating environment and the prospect for improving results and expense reductions. Such statements are inherently subject to certain risks and uncertainties. Actual future results and trends could differ materially from those set forth in such statements due to various factors. Such factors include the impact of our ratings downgrade or a further lowering or loss of one of our financial strength ratings; the impact of the restatement on our ratings and client relationships; uncertainties of assumptions used in our reserving process; risk associated with implementing our business strategies and our capital improvement measures and the run-off of our North American business; cyclicality of the reinsurance industry; the occurrence of natural and man-made catastrophic events with a frequency or severity exceeding our estimates; acts of terrorism and acts of war; changes in economic conditions, including interest and currency rate conditions that could affect our investment portfolio; actions of competitors, including industry consolidation and development of competing financial products; a decrease in the level of demand for our reinsurance or increased competition in our industries or markets; a loss of our key employees or executive officers without suitable replacements being recruited within a suitable period of time; our ability to address material weaknesses we have identified in our internal control environment; political risks in the countries in which we operate or in which we reinsure risks; the passage of additional legislation or the promulgation of new regulation in a jurisdiction in which we or our clients operate or where our subsidiaries are organized; the effect on us and the insurance industry as a result of the investigations being carried out by the US Securities and Exchange Commission, New York's Attorney General and other governmental authorities; changes in our investment results due to the changed composition of our invested assets or changes in our investment policy; failure of our retrocessional reinsurers to honor their obligations or changes in the credit worthiness of our reinsurers; our failure to prevail in any current or future arbitration or litigation; and extraordinary events affecting our clients, such as bankruptcies and liquidations, and other risks and uncertainties, including those detailed in the Company's filings with the U.S. Securities and Exchange Commission and the SWX Swiss Exchange. The Company does not assume any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. CONVERIUM HOLDING AG By: /s/ Inga Beale Name: Inga Beale Title: CEO By: /s/ Christian Felderer Name: Christian Felderer Title: General Legal Counsel Date:December 20, 2006