ATLANTIC MUTUAL TO SELL ITS COMMERCIAL INSURANCE BUSINESS TO ONEBEACON

New York, NY, December 5, 2003 - Atlantic Mutual announced it has signed an agreement in principle to sell its subsidiary, Atlantic Specialty Insurance Company, and the renewal rights to its commercial insurance business, including the unearned premiums on the acquired book, to OneBeacon Insurance Company. The overall gross written premium for this book of business totals approximately $450 million. Consummation of the transaction is subject to regulatory approval and other conditions.

"This transaction will allow Atlantic Mutual to go forward as a well capitalized writer of affluent personal lines with a premium to surplus ratio lower than one to one," said Klaus Dorfi, chairman and CEO of Atlantic Mutual. "At the same time, our commercial business represents a very complementary fit for OneBeacon. Our commercial insurance division employees, producers and policyholders should experience a smooth transition."

About The Atlantic Companies

The Atlantic Companies, also known as Atlantic Mutual, is a group of diversified financial services companies with a Wall Street heritage dating back to 1842. The group is widely known for the Atlantic Master Plan insurance program, which is designed specifically for affluent individuals and sold through a select group of independent agents. The Atlantic Companies acts as a property-casualty insurer, manages claims for commercial insurance, and helps other business partners target profitable niches in the insurance marketplace. Additional information about The Atlantic Companies and the Atlantic Master Plan can be found at www.atlanticmasterplan.com.


Contact: Peter G. Scott
Corporate Marketing & Communications
973-408-6044