Filed by Old National Bancorp

Pursuant to Rule 425 under the Securities Act of 1933

Subject Company: United Bancorp, Inc.

Commission File No.: 000-16640

The following excerpts relating to Old National Bancorp’s pending acquisition of United Bancorp, Inc. are from the slide presentation of a conference call held by executive officers of Old National on April 28, 2014 in connection with Old National’s announcement of its financial results for the quarter ended March 31, 2014.

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Additional Information for Shareholders of United Bancorp, Inc.

Communication in this presentation does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval. In connection with the proposed merger, Old National has filed with the SEC a Registration Statement on Form S-4 that includes a preliminary Proxy Statement of United Bancorp, Inc. (“United”) and a preliminary Prospectus of Old National, and each of Old National and United has filed and will file other relevant documents concerning the proposed transaction. A definitive Proxy Statement/Prospectus will be mailed to shareholders of United. United Shareholders are urged to read the Registration Statement and the definitive Proxy Statement/Prospectus regarding the merger when it becomes available and any other relevant documents filed with the SEC, as well as any amendments or supplements to those documents, because they will contain important information. A free copy of the Proxy Statement/Prospectus, as well as other filings containing information about Old National and United, may be obtained at the SEC’s Internet site (http://www.sec.gov). You will also be able to obtain these documents (when available), free of charge, from Old National at www.oldnational.com under the tab “Investor Relations” and then under the heading “Financial Information” or from United by accessing United’s website at www.ubat.com under the tab “Investor Relations” and then under the heading “SEC Filings.”

Old National and United and certain of their directors and executive officers may be deemed to be participants in the solicitation of proxies from the shareholders of United in connection with the proposed merger. Information about the directors and executive officers of Old National is set forth in the proxy statement for Old National’s 2014 annual meeting of shareholders, as filed with the SEC on a Schedule 14A on March 14, 2014. Information about the directors and executive officers of United is set forth in United’s Annual Report on Form 10-K, as filed with the SEC on February 28, 2014. Additional information regarding the interests of those participants and other persons who may be deemed participants in the transaction may be obtained by reading the Proxy Statement/Prospectus regarding the proposed merger when it becomes available. Free copies of this document may be obtained as described in the preceding paragraph.

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Forward-Looking Statement

This presentation contains certain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements include, but are not limited to, descriptions of Old National Bancorp’s financial condition, results of operations, asset and credit quality trends and profitability and statements about the expected timing, completion, financial benefits and other effects of Old National Bancorp’s proposed merger with United Bancorp, Inc. (“United”). Forward-looking statements can be identified by the use of the words “anticipate,” “believe,” “expect,” “intend,” “could” and “should,” and other words of similar meaning. These forward-looking statements express management’s current expectations or forecasts of future events and, by their nature, are subject to risks and uncertainties and there are a number of factors that could cause actual results to differ materially from those in such statements. Factors that might cause such a difference include, but are not limited to: expected cost savings, synergies and other financial benefits from the merger with Tower Financial Corporation and proposed merger with United might not be realized within the expected time frames and costs or difficulties relating to integration matters might be greater than expected; the requisite shareholder and regulatory approvals for the United merger might not be obtained; market, economic, operational, liquidity, credit and interest rate risks associated with Old National Bancorp’s businesses; competition; government legislation and policies (including the impact of the Dodd-Frank Wall Street Reform and Consumer Protection Act and its related regulations); ability of Old National Bancorp to execute its business plan (including its proposed acquisition of United Bancorp, Inc.); changes in the economy which could materially impact credit quality trends and the ability to generate loans and gather deposits; failure or circumvention of our internal controls; failure or disruption of our information systems; significant changes in accounting, tax or regulatory practices or requirements; new legal obligations or liabilities or unfavorable resolutions of litigations; other matters discussed in this presentation and other factors identified in Old National Bancorp’s Annual Report on Form 10-K and other periodic filings with the Securities and Exchange Commission (“SEC”). These forward-looking statements are made only as of the date of this presentation, and Old National Bancorp does not undertake an obligation to release revisions to these forward-looking statements to reflect events or conditions after the date of this presentation.

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Update on Partnerships

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Executing The Plan – 2014

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Old National Bancorp

Appendix

18 Efficiency Ratio 1 1 Calculation excludes net securities gains and intangible amortization Incentive basis calculation excludes merger and integration charges and impact for current year partnerships 68.34% 66.56% 67.77% 68.25% 63.97% 65.81% 1Q13 4Q13 1Q14 ONB Incentive Basis for Efficiency Ratio Non-GAAP financial measure which Management believes is useful in evaluating the financial results of the Company – see Appendix for Non-GAAP reconciliation

Executing The Plan – 2014

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Old National Bancorp

Appendix

28 Returned to community bank model 2004 2005 Sold non- strategic market – Clarksville, TN – 5 branches 2006 Sold non- strategic market – O’Fallon, IL – 1 branch 2007 2008 2009 2010 2011 2012 2013 Acquired St. Joseph Capital – Entry into Northern IN market    February, 2007 Acquired 65 Charter One branches throughout Indiana        March, 2009 Acquired Monroe Bancorp – Enhanced Bloomington, IN presence        January, 2011 Acquired IN Community – Entry into Columbus, IN  September, 2012 FDIC-assisted acquisition of Integra Bank    July, 2011 Sold non- strategic market – Chicago-area - 4 branches Consolidation of 21 branches Acquired 24       MI / IN branches  July, 2013 Consolidation of 2 branches Consolidation of 8 branches Consolidation of 1 branch Consolidation of 10 branches Consolidation of 12 branches Consolidation of 44 branches Consolidation of 5 branches Sold  12  branches Consolidation of 22 branches Purchased 182 + 18 pending Sold 22 Consolidated 128 Acquired Tower Financial – Enhancing Ft. Wayne, IN presence April, 2014 Transforming Old National’s Landscape Pending acquisition of United Bancorp – Entry into   Ann Arbor, MI 2014 Consolidation of 3 branches

44 Non-GAAP Reconciliations Efficiency Ratio - As Reported 1Q13 4Q13 1Q14 Net Interest Income (FTE) $83.0 $85.5 $87.4 Noninterest Income Less Security Gains 45.3 44.1 40.1 Revenue Less Security Gains 128.3 129.6 127.5 Noninterest Expense 90.2 88.2 88.3 Intangible Amortization 2.5 1.9 1.8 Noninterest Expense Less Intangible Amortization 87.7 86.3 86.4 Efficiency Ratio 68.34% 66.56% 67.77% Impact of Current Year Partnerships 1Q13 4Q13 1Q14 Net Interest Income (FTE) $0.0 $1.7 $0.0 Noninterest Income Less Security Gains 0.0 1.8 0.0 Revenue Less Security Gains 0.0 3.5 0.0 Noninterest Expense 0.1 5.8 2.5 Intangible Amortization 0.0 0.2 0.0 Noninterest Expense Less Intangible Amortization 0.1 5.6 2.5 Efficiency Ratio Excluding Impact of Current Year Partnerships 1Q13 4Q13 1Q14 Net Interest Income (FTE) $83.0 $83.9 $87.4 Noninterest Income Less Security Gains 45.3 42.3 40.1 Revenue Less Security Gains 128.3 126.1 127.5 Noninterest Expense 90.0 82.4 85.8 Intangible Amortization 2.5 1.7 1.8 Noninterest Expense Less Intangible Amortization 87.5 80.7 83.9 Efficiency Ratio 68.25% 63.97% 65.81% $ in thousands