2010-02-02 22:58:04 -

A.M. Best Co. has placed the financial strength ratings of A (Excellent) and issuer credit ratings of “a” of Massachusetts Homeland Insurance Company (Mass Homeland) (Canton, MA) and York Insurance Company of Maine (York) (South Portland, ME) under review with negative implications.

The rating actions reflect the recent announcement by OneBeacon Insurance Group, Ltd. (OneBeacon) that these two 100% reinsured subsidiaries are to be sold to Tower Group, Inc. (Tower), (headquartered in New York) (NASDAQ: TWGP) as part of a transaction to sell OneBeacon’s personal lines business. As a result, the existing reinsurance agreements in place that cede 100% of Mass Homeland and York’s businesses to OneBeacon Insurance Company are expected to be commuted at the close of the transaction in

mid-2010, depending on regulatory approvals. Mass Homeland and York’s ratings will remain under review pending the close of the transaction and regulatory approval of affiliated reinsurance agreements between the acquired companies and certain Tower subsidiaries. The transaction has no other impact on the ratings of OneBeacon or its 75% shareholder, White Mountains Insurance Group, Ltd.

For Best’s Credit Ratings, an overview of the rating process and rating methodologies,. please visit www.ambest.com/ratings : .

The principal methodologies used in determining these ratings, including any additional methodologies and factors that may have been considered, can be found at www.ambest.com/ratings/methodology : .



Founded in 1899, A.M. Best Company is a global full-service credit rating organization dedicated to serving the financial and health care service industries, including insurance companies, banks, hospitals and health care system providers. For more information, visit www.ambest.com : .



A.M. Best Co.Analysts:Marc Liebowitz,

908-439-2200, ext. 5071 marc.liebowitz@ambest.com : mailto:marc.liebowitz@ambest.com orGerard
Altonji, 908-439-2200, ext. 5626 gerard.altonji@ambest.com : mailto:gerard.altonji@ambest.com orPublic
Relations:Jim Peavy, 908-439-2200, ext. 5644 james.peavy@ambest.com : mailto:james.peavy@ambest.com orRachelle
Morrow, 908-439-2200, ext. 5378 rachelle.morrow@ambest.com : mailto:rachelle.morrow@ambest.com