A.M. Best Comments on Argo Group International Holdings, Ltd. Offer for Heritage Underwriting Agency plc

A.M. Best Co. has commented that the financial strength ratings, issuer credit ratings and debt ratings of Argo Group International Holdings, Ltd. (Argo Group) (Hamilton, Bermuda) [NASDAQ: AGII] and its insurance subsidiaries are unchanged. The outlook for all ratings is stable.

This comment follows today’s announcement of Argo Group’s $272 million cash offer to acquire Heritage Underwriting Agency plc (Heritage) [LSE: HUA], a Lloyd’s insurer specializing in worldwide property and non-U.S. liability business. The combination of Argo and Heritage will create a broader underwriting platform as well as an extended geographic capability and distribution network for Argo.

The acquisition of Heritage is expected to close in the second half of 2008, subject to relevant legal and regulatory requirements and the satisfaction of customary conditions for a transaction of this type.

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.