For Shareholders

HAMILTON, Bermuda, November 2, 2001 – White Mountains Insurance Group Ltd. announced today it is seeking to establish a new Bermuda-based property and casualty reinsurer to respond to the current favorable underwriting and pricing environment in the reinsurance industry. The Company intends to focus initially on property reinsurance business through the broker market. The Company is expected to be capitalized with at least $1.0 billion. White Mountains will be a founding shareholder and is expected to invest at least $200 million.

Jack Byrne will become Chairman of The Company. Byrne is currently Chairman of White Mountains and Chairman of OneBeacon Insurance Group. He was formerly Chairman and CEO of GEICO and of Fireman's Fund Corporation. Anthony Taylor, formerly Deputy Chairman of Wellington Holdings plc, a publicly traded Lloyd's underwriting vehicle, will become CEO and Chief Underwriting Officer of the Company as of 1 January, 2002. Anthony Taylor has 25 years of experience in the worldwide reinsurance business.

Jack Byrne said today "We are pleased to be supporting the launch of this new venture. Led by Tony and my associates, I believe we have assembled a high quality team to establish the Company at a time of significant opportunity in the global reinsurance markets."

Anthony Taylor said "Our new Company will be a customer-focused reinsurer providing solutions and support in the world wide property and casualty reinsurance marketplace."

Banc of America Securities LLC and Benfield Advisory Limited are acting as financial advisers to the Company.

White Mountains is a Bermuda-based insurance holding company traded on the New York Stock Exchange under the symbol WTM.

The Private Securities Litigation Reform Act of 1995 provides a 'safe harbor' for forward looking statements: Statements made in this news release, or any other statements made by or on behalf of the Company or White Mountains, may contain information about future business prospects. These statements may be considered "forward-looking." These statements are subject to risks and uncertainties that could cause actual results to differ materially from those set forth in or implied by such forward-looking statements, including statements regarding the completion of the capitalization of the Company, prospects for the Company's, future financial results and the reinsurance industry's underwriting and pricing environment. For further information regarding cautionary statements and factors affecting White Mountains' future operations results, please refer to White Mountains Insurance Group Ltd 's filings with the Securities and Exchange Commission including its annual report on Form 10-K for the year ended December 31, 2000 and Form 10-Q for the quarters ended March 31, 2001 and June 30, 2001 and its current reports on Form 8-K filed in 2001.

CONTACT:

Dennis Beaulieu, White Mountains Insurance Group Ltd - 603-640-2206