FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * FASS STEVE ELLIOTT   2. Issuer Name and Ticker or Trading Symbol WHITE MOUNTAINS INSURANCE GROUP LTD [WTM] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) President & CEO (Last) (First) (Middle) C/O WHITE MOUNTAINS INSURANCE GROUP, LTD, 80 SOUTH MAIN STREET 3. Date of Earliest Transaction (Month/Day/Year) 04/28/2006 (Street) HANOVER, NH 03755 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Shares (restricted)               10,000 D   Common Shares               3,958 (1) I By 401(k)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Phantom Shares (Deferred Compensation)

(2)

(3)

(3)

Common Shares

(2)

14,229

D

Phantom Shares (Deferred Compensation)

(2)

04/28/2006

I

1,000

(4)

(4)

Common Shares

1,000

$ 508

4,127

D

Common Share Options

(5)

(6)

02/28/2010

Common Shares

0

9,000

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
FASS STEVE ELLIOTT C/O WHITE MOUNTAINS INSURANCE GROUP, LTD 80 SOUTH MAIN STREET HANOVER, NH 03755	X		President & CEO

Signatures

Dennis Beaulieu, by Power of Attorney		05/01/2006
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Since March 23, 2006, the date of Reporting Person's last filing, Reporting Person acquired 24 shares of WTM Common Shares under the Folksamerica 401(k) Plan. WTM Common Shares are purchased at fair market value on the date of purchase. The information in this report is based on a plan statement dated as of March 31, 2006.
(2)	Phantom Shares are convertible into Common Shares on a 1 for 1 basis.
(3)	The Phantom Shares are payable, at the election of the Company, in cash or in Common Shares, following termination of the Reporting Person's employment with the Company or beginning at an earlier date selected by the Reporting Person in accordance with the terms of the deferred compensation plan.
(4)	The Phantom Shares are payable in cash following termination of the Reporting Person's employment with the Company.
(5)	On February 28, 2000, the Reporting Person was granted options to purchase WTM Common Shares on a 1 for 1 basis at an initial exercise price of $106.19. The exercise price increases by 6% annually on a cumulative basis.
(6)	Reporting Person was originally granted 9,000 options to purchase Common Shares on February 28, 2000. 900 Options become exercisable annually over a ten-year period.

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