UNITED STATES

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                -------------

                                   FORM 8-K/A

                                 CURRENT REPORT

              Pursuant to Section 13 or 15(d) of the Securities
                             Exchange Act of 1934


                               NOVEMBER 1, 2001
               Date of Report (Date of earliest event reported)


                    WHITE MOUNTAINS INSURANCE GROUP, LTD.
            (Exact name of registrant as specified in its charter)



        BERMUDA                         1-8993                  94-2708455
(State or other jurisdiction of       (Commission             (I.R.S. Employer
incorporation or organization)        file number)           Identification No.)



                 28 GATES STREET, WHITE RIVER JUNCTION, VERMONT 05001-7066
                          (Address of principal executive offices)


                                (802) 295-4500
             (Registrant's telephone number, including area code)



ITEM 2.    DISPOSITION OF ASSETS (OR BUSINESS)

White Mountains' wholly owned subsidiary, OneBeacon Insurance Group (consisting
of OneBeacon Insurance Group LLC and its subsidiaries, "OneBeacon"), previously
announced that it has executed a definitive agreement with Liberty Mutual
Insurance Group ("Liberty Mutual"). The agreement calls for Liberty Mutual,
beginning November 1, 2001 (the "Effective Date"), to assume new and renewal
commercial and personal lines business produced by OneBeacon agents in 42 states
and the District of Columbia. Additionally, OneBeacon will reinsure 67% of the
renewal premiums written and the net liability for loss and loss adjustment
expense of all renewal policies subject to the agreement during the first twelve
months after the Effective Date of the transaction and 33% of such net premiums
written and net liability for loss and loss adjustment expenses during the
following twelve months.

The press release issued by OneBeacon dated September 5, 2001 and a summary of
significant terms of the agreement in principle between OneBeacon and Liberty
Mutual were previously filed as Exhibits 99 (a) and 99 (b), respectively, to the
Form 8-K dated September 5, 2001 (filed September 7, 2001). The press release
issued by OneBeacon dated October 30, 2001 was previously filed as Exhibit 99
(c) to the Form 8-K amendment dated September 5, 2001 (filed October 31, 2001).

Also previously filed as Exhibits 99(d), 99(e), 99(f), 99(g) and 99(h) to Form
8-K dated September 5, 2001 (filed November 6, 2001) were the Master Agreement
by and among the Registrant, OneBeacon and Liberty Mutual, a Glossary of Terms
to the Master Agreement, the Renewal Rights Agreement by and among OneBeacon and
Liberty Mutual, the Peerless Post-Closing Indemnity Reinsurance Agreement by and
between OneBeacon and Peerless Insurance Company and the Rewritten Indemnity
Reinsurance Agreement by and between Peerless Insurance Company and OneBeacon,
respectively. The unaudited pro forma condensed combined income statements of
the Registrant for the year ended December 31, 2000 and the nine month period
ended September 30, 2001 were previously filed as Exhibit 99(i) to Form 8-K
dated November 1, 2001 (filed January 14, 2002).

The unaudited pro forma condensed combined income statement of the Registrant
for the year ended December 31, 2001 is enclosed herein as Exhibit 99(j), which
is incorporated by reference in its entirety.

This Current Report on Form 8-K amends the Form 8-K dated November 1, 2001 and
filed on May 15, 2002. The amendment serves to remove the following items from
the pro forma condensed income statement for the year ended December 31, 2001:
(i) the financial impact of certain material non-recurring transactions which
were entered into contemporaneously with the acquisition of OneBeacon; and (ii)
pro forma adjustments made in connection with the Renewal Rights Agreement, as
such information has been supplanted with a narrative disclosure of the effects
of this transaction on the operating results of the Registrant.

ITEM 7.    FINANCIAL STATEMENTS AND EXHIBITS.

    (b)     PRO FORMA FINANCIAL INFORMATION.

            The amended unaudited pro forma condensed combined income statement
            of the Registrant for the year ended December 31, 2001, and the
            notes thereto, are enclosed herein as Exhibit 99(j).



    (c)     Exhibits.  The following exhibits are filed herewith:

   EXHIBIT NO.       DESCRIPTION
   -----------       -----------

      99(j)          The amended unaudited pro forma condensed combined income
                     statement of the Registrant for the year ended
                     December 31, 2001 and the notes thereto.

                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                           WHITE MOUNTAINS INSURANCE GROUP, LTD.



Dated: July 15, 2002             By:  /s/    J. Brian Palmer
                                             ---------------
                                             Chief Accounting Officer