Exhibit (a)(1)(I)


[WHITE MOUNTAINS INSURANCE GROUP LOGO]               PRESS
                                                     RELEASE

                                                     CONTACT: Mike Paquette
                                                     (603) 640-2205



                   WHITE MOUNTAINS COMMENCES CASH TENDER OFFER
                  FOR UP TO 1,500,000 SHARES AT $165 PER SHARE


HAMILTON, Bermuda, August 21, 2000 - White Mountains Insurance Group, Ltd. today
commenced its previously announced cash tender offer to purchase up to 1,500,000
of its common shares at $165 per share, net to the seller in cash, upon the
terms and subject to the conditions set forth in the Offer to Purchase dated
August 21, 2000, and the related Letter of Transmittal (which together
constitute the "Offer").

The Offer is not conditioned upon any minimum number of shares being tendered.
The Offer is, however, subject to certain conditions. The Offer, proration
period and withdrawal rights are scheduled to expire at 12:00 midnight, New York
City time, on Monday, September 18, 2000 unless the Offer is extended.

Equiserve Trust Company is the Information Agent for the Offer and can be
reached at 1-888-756-1854.

Neither the Company, its Board of Directors nor the Information Agent makes any
recommendation as to whether any shareholder should participate in the Offer.