UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                  -------------

                                    FORM 8-K

                                 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.)


               80 SOUTH MAIN STREET, HANOVER, NEW HAMPSHIRE 03755
                    (Address of principal executive offices)


                                 (603) 643-1567
              (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 Corporation 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 66 2/3% of
the net premiums written and the net liability for loss and loss adjustment
expense of all policies subject to the agreement during the first twelve months
after the Effective Date of the transaction and 33 1/3% 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 non- binding 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).

Included as Exhibits 99(d), 99(e), 99(f), 99(g) and 99(h) to this Current Report
on Form 8-K are 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, which are incorporated
by reference herein in their entirety.


ITEM 7.         FINANCIAL STATEMENTS AND EXHIBITS.

     (b)        PRO FORMA FINANCIAL INFORMATION.

                Pro Forma Financial Information. The pro forma financial
                information required by part (b) of Item 7 relating to the
                Renewal Rights Agreement with Liberty Mutual (which became
                effective November 1, 2001) is not currently available. The
                Company will provide the requisite financial information,
                prepared in accordance with Regulation S-X, in an amendment to
                this report within 60 days of the date of this report.





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

     EXHIBIT NO.   DESCRIPTION

     99 (d)        Master Agreement by and among the Registrant, OneBeacon and
                   Liberty Mutual.

     99 (e)        A Glossary of Terms to the Master Agreement.

     99 (f)        Renewal Rights Agreement by and among OneBeacon and Liberty
                   Mutual.

     99 (g)        Peerless Post-Closing Indemnity Reinsurance Agreement by and
                   between OneBeacon and Peerless Insurance Company

     99 (h)        Rewritten Indemnity Reinsurance Agreement by and between
                   Peerless Insurance Company and OneBeacon.


                                   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: November 5, 2001          By: /s/ J. BRIAN PALMER
                                     -----------------------------------
                                     Chief Accounting Officer