Liberty Mutual Group to Acquire Ohio Casualty Corporation

Business Wire, May 7, 2007

Rated A (Excellent) for financial strength by the A.M. Best Company, Inc., the Group has written premiums of approximately $1.42 billion as of Dec. 31, 2006. OCG products are marketed through approximately 3,400 independent agencies. Policies may be underwritten by The Ohio Casualty Insurance Company, West American Insurance Company, American Fire and Casualty Company, Ohio Security Insurance Company, Avomark Insurance Company or Ohio Casualty of New Jersey, Inc.

Cautionary Notice Regarding Forward Looking Statements

Certain statements in this press release contain forward-looking statements, including statements relating to results of operations. These forward-looking statements are based on current expectations, estimates, forecasts and projections of future company or industry performance based on management's judgment, beliefs, current trends and market conditions. Actual outcomes and results may differ materially from what is expressed, forecasted or implied in any forward-looking statement. Forward-looking statements made by Ohio Casualty or Liberty Mutual may be identified by the use of words such as "will," "expects," "intends," "plans," "anticipates," "believes," "seeks," "estimates," and similar expressions. There are a number of risks and uncertainties that could cause actual results to differ materially from the forward-looking statements included in this document. For example, (1) Ohio Casualty may be unable to obtain shareholder approval required for the transaction; (2) regulatory approvals required for the transaction may not be obtained, or required regulatory approvals may delay the transaction or result in the imposition of conditions that could have a material adverse effect on Ohio Casualty or Liberty Mutual or cause the parties to abandon the transaction; (3) conditions to the closing of the transaction may not be satisfied; (4) the business of Ohio Casualty or Liberty Mutual may suffer as a result of uncertainty surrounding the transaction; and (5) Ohio Casualty or Liberty Mutual may be adversely affected by other economic, business, and/or competitive factors. These and other factors that could cause Ohio Casualty's actual results to differ materially from those expressed or implied are discussed under "Risk Factors" in Ohio Casualty's most recent annual report on Form 10-K and other filings with the Securities and Exchange Commission. For a further discussion of these and other risks and uncertainties affecting Liberty Mutual, see Liberty Mutual's website at www.libertymutual.com/investors. Ohio Casualty and Liberty Mutual undertake no obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise. Readers are cautioned not to place undue reliance on these forward-looking statements.

Additional Information and Where to Find It

This communication may be deemed to be solicitation material in respect of the proposed transaction. In connection with the proposed transaction, a proxy statement of Ohio Casualty and other materials will be filed with the SEC. WE URGE INVESTORS TO READ THE PROXY STATEMENT AND THESE OTHER MATERIALS CAREFULLY WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT OHIO CASUALTY CORPORATION AND THE PROPOSED TRANSACTION. Investors will be able to obtain free copies of the proxy statement (when available) as well as other filed documents containing information about Ohio Casualty on the SEC's website at http://www.sec.gov. Free copies of Ohio Casualty's SEC filings are also available from Ohio Casualty Corporation, 9450 Seward Road, Fairfield, Ohio 45014, Attention: Investor Relations.