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

May 18, 2010

Date of Report (Date of earliest event reported)

WHITE MOUNTAINS INSURANCE GROUP, LTD.

(Exact name of registrant as specified in its charter)

80 South Main Street, Hanover, New Hampshire 03755

(Address of principal executive offices)

(603) 640-2200

(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

o    Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o    Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o    Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

ITEM 7.01               Regulation FD.

The Registrant’s executive officers intend to utilize the presentation attached as Exhibit 99.1 to this Form 8-K, in whole or in part, at the Registrant’s Annual Investor Information Meeting to be held on May 18, 2010.

ITEM 9.01     Financial Statements and Exhibits

(d) Exhibits.  The following exhibit is furnished herewith:

EXHIBIT INDEX

99.1 Supplemental Regulation FD Disclosure.

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.

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