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

FORM 11-K

(Mark One)
ý	Annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934
For the fiscal year ended December 31, 2002
OR
o	Transition report pursuant to Section 15(d) of the Securities Exchange Act of 1934
For the transition period from                             to

Commission file number 1-8993

A.

Full title of the plan and the address of the plan, if different from that of the issuer named below:

ONEBEACON INSURANCE SAVINGS PLAN

B.

Name of issuer of the securities held pursuant to the plan and the address of its principal executive office:

WHITE MOUNTAINS INSURANCE GROUP, LTD.
80 South Main Street
Hanover, NH 03755
(603) 640-2200

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EXPLANATORY NOTE

        This Annual Report on Form 11-K is being filed so that it may be incorporated by reference into a Registration Statement on Form S-8 which White Mountains Insurance Group, Ltd. is filing with respect Common Shares, $1.00 par value per share, of White Mountains Insurance Group, Ltd. issuable under the Plan.

INFORMATION FILED

        The following financial statements and exhibit are filed with, and included in, this Report:

A.

Financial statements for the Plan consisting of:



1.

Report of Independent Auditors;



2.

Statements of Net Assets Available for Plan Benefits as of December 31, 2002 and 2001;



3.

Statements of Changes in Net Assets Available for Plan Benefits for the years ended December 31, 2002 and 2001;



4.

Notes to Financial Statements;



5.

Schedule of Assets Held at End of Year as of December 31, 2002; and



B.

Consent of Independent Auditors



C.

Certifications pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

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SIGNATURES

        THE PLAN. Pursuant to the requirements of the Securities Exchange Act of 1934, the trustees (or other persons who administer the employee benefit plan) have duly caused this annual report to be signed on its behalf by the undersigned, thereunto duly authorized.

		ONEBEACON INSURANCE SAVINGS PLAN (the "Plan")
Date: June 27, 2003		By:		/s/  THOMAS N. SCHMITT       Title: Senior Vice President, Human Resources One Beacon Insurance Company (the Plan Administrator)

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EXHIBIT INDEX

EXHIBIT NUMBER		DESCRIPTION
99(A)		Financial statements for the Plan consisting of:
		1.		Report of Independent Accountants;
		2.		Statements of Net Assets Available for Plan Benefits as of December 31, 2002 and 2001;
		3.		Statements of Changes in Net Assets Available for Plan Benefits for the years ended December 31, 2002 and 2001;
		4.		Notes to Financial Statements;
		5.		Schedule of Assets Held at End of Year as of December 31, 2002; and
99(B)		Consent of Independent Accounts
99(C)		Certifications pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

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EXPLANATORY NOTE
INFORMATION FILED
SIGNATURES
EXHIBIT INDEX

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Exhibit 99(A)

OneBeacon Insurance Savings Plan

Financial Statements and Supplemental Schedule to
Accompany 2002 Form 5500
Annual Report of Employee Benefit Plan
Under ERISA of 1974
For the Years Ended December 31, 2002 and 2001

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OneBeacon Insurance Savings Plan

Index of Financial Statements and Supplemental Schedule

			Page(s)
Report of Independent Accountants			2
Statements of Net Assets Available for Benefits December 31, 2002 and 2001			3
Statements of Changes in Net Assets Available for Benefits For the years ended December 31, 2002 and 2001			4
Notes to Financial Statements			5-9
Supplemental schedule *:
	Schedule of Assets (Held at End of Year) December 31, 2002		10-13

*

Other schedules required by Section 2520.103-10 of the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974 have been omitted because they are not applicable.

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Report of Independent Auditors

To the Participants and Administrator of
OneBeacon Insurance Savings Plan

        In our opinion, the accompanying statements of net assets available for benefits and the related statements of changes in net assets available for benefits present fairly, in all material respects, the net assets available for benefits of OneBeacon Insurance Savings Plan (the "Plan") at December 31, 2002 and 2001, and the changes in net assets available for benefits for the years then ended in conformity with accounting principles generally accepted in the United States of America. These financial statements are the responsibility of the Plan's management; our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits of these statements in accordance with auditing standards generally accepted in the United States of America, which require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

        Our audits were conducted for the purpose of forming an opinion on the basic financial statements taken as a whole. The supplemental schedule of assets (held at end of year) at December 31, 2002 is presented for the purpose of additional analysis and is not a required part of the basic financial statements but is supplementary information required by the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. This supplemental schedule is the responsibility of the Plan's management. The supplemental schedule has been subjected to the auditing procedures applied in the audits of the basic financial statements and, in our opinion, is fairly stated in all material respects in relation to the basic financial statements taken as a whole.

        As further described in Notes H and I, certain participant balances from the Plan were transferred into the Liberty Mutual Thrift Incentive Plan and the CGNU Service Corporation 401(k) Plan in January, 2002 and June 1, 2001, respectively.

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts
June 26, 2003

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OneBeacon Insurance Savings Plan

Statements of Net Assets Available for Benefits

December 31, 2002 and 2001

					2002			2001
Assets
	Investments:
		Investments at fair value (Notes B,C,D,E)			$	338,146,120		$	422,169,931
		Loans to participants at fair value (Note A)				5,311,372			10,429,873
						343,457,492			432,599,804
	Receivables:
		Employer contributions				38,858			25,347
		Participant contributions				121,212			58,832
						160,070			84,179
			Net assets available for benefits		$	343,617,562		$	432,683,983

The accompanying notes are an integral part of these financial statements.

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OneBeacon Insurance Savings Plan

Statements of Changes in Net Assets Available for Benefits

For the years ended December 31, 2002 and 2001

					2002			2001
Additions
	Investment income:
		Interest and dividend income (Notes C and D)			$	7,524,446		$	11,918,358
		Interest income, participant loans (Note A)				426,113			952,791
		Net appreciation/(depreciation) in fair value of investments (Note D)				(31,453,150	)		(15,724,301	)
						(23,502,591	)		(2,853,152	)
	Contributions:
		Employer				6,498,091			13,780,347
		Participant				14,884,759			22,074,918
						21,382,850			35,855,265
	Transfers in—rollovers					2,841,350			2,452,279
	Other increases					15,734			23,275
			Total additions			737,343			35,477,667
Deductions
	Benefits paid to participants					72,560,525			37,471,405
	Miscellaneous					621			23,164
			Total deductions			72,561,146			37,494,569
Net decrease excluding transfer out						(71,823,803	)		(2,016,902	)
Transfers out—(Notes H and I)						(17,242,618	)		(6,660,142	)
Net decrease						(89,066,421	)		(8,677,044	)
Net assets available for benefits:
	Beginning of year					432,683,983			441,361,027
	End of year				$	343,617,562		$	432,683,983

The accompanying notes are an integral part of these financial statements.

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OneBeacon Insurance Savings Plan

A.    Description of the Plan

        The following description of the OneBeacon Insurance Savings Plan ("Plan") provides only general information. Participants should refer to the Plan agreement for a more complete description of the Plan's provisions.

General

        The Plan is a defined contribution plan covering substantially all employees of OneBeacon Insurance Company (the "Company"). It is subject to the provisions of the Employee Retirement Income Security Act of 1974 ("ERISA").

        On June 1, 2001 the Company was sold to White Mountains Insurance Group, Ltd. and the Plan was amended to change the name of the Plan from CGU Savings Plan to OneBeacon Insurance Savings Plan.

Eligibility

        Employees who complete sixty days of continuous service are eligible to participate in the Plan. Eligible employees are automatically enrolled in the Plan at a 2 percent contribution rate, unless waived by the employee.

Contributions

        During 2002 and 2001, the maximum participants could contribute each year was 18 percent of annual compensation on a pre-tax and/or an after-tax basis, as defined in the Plan. Effective January 1, 2003, participants may contribute 40 percent of annual compensation on a pre-tax and/or an after-tax basis. Participants direct their contributions into various investment options offered by the Plan. During 2002 and 2001, the Company contributed on behalf of the participant 100 percent of the first 2 percent and 50 percent of the next 4 percent of base compensation that a participant contributes to the Plan. Effective January 1, 2003, the Company contributes 50 percent of the first 6 percent of base compensation that a participant contributes to the Plan. During 2002, fifty percent of the Company matching contribution was invested in the White Mountains Stock Fund and all remaining contributions were invested in the employee directed investment options. Effective January 1, 2003, the company match will mirror the employee directed investment options. Effective January 1, 2003, eligible participants who attain age 50 before the end of the Plan year may make catch up contributions to the Plan. Contributions are subject to IRS limitations.

        Employees who were employed on or before the sale completion date of June 1, 2001 and who remained as active employees as of December 31, 2001 were provided with the equivalent of two common shares of White Mountains Insurance Group, Ltd., which were directed into the White Mountains Stock Fund within the employee's plan account on December 31, 2001. Employees who were not participating in the Plan had an account opened for them for this grant. Contributions into the White Mountains Stock Fund can be immediately directed by the participant into another investment option.

        Employees hired between June 1, 2001 and April 11, 2003 will be provided with the equivalent of two common shares of White Mountains Insurance Group, Ltd. on the first day of the second month of the quarter following one year of service with the Company. In 2002, the Company contributed $141,417 to participants hired between June 1, 2001 and September 30, 2001. Contributions into the White Mountains Stock Fund can be immediately directed by the participant into another investment option.

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Participant Accounts

        Each participant's account is credited with the participant's contribution and allocations of (a) the Company's contribution and (b) Plan earnings, net of an allocation of administrative expenses. Allocations are based on participant earnings or account balances, as defined. The benefit to which a participant is entitled is the benefit that can be provided from the participant's vested account.

Vesting

        Participants are vested immediately in their contributions plus actual earnings thereon. Vesting in the Company's contribution portion of their accounts is based on years of continuous service. A participant is 100 percent vested after three years of credited service.

Forfeitures

        Forfeitures are used to reduce future Company contributions. The balances as of December 31, 2002 and 2001, in the forfeiture account were $6,727 and $903, respectively. During 2002 and 2001, $329,014 and $224,108, respectively, of forfeited funds were used to offset employer contributions.

Participant Loans

        Participants may borrow from their fund accounts a minimum of $500 up to a maximum of $50,000 or 50 percent of their vested account balance, whichever is less. The loans are secured by the balance in the participant's account and bear interest at the prime rate (4.25 and 4.75 at December 31, 2002 and December 31, 2001, respectively) plus 1 percent as of the beginning of the month in which the loan was made.

Payment of Benefits

        On termination of service due to death, disability, or retirement, a participant may elect to receive either a lump-sum amount equal to the value of the participant's vested interest in his or her account, or annual installments over time. For termination of service for other reasons, a participant may only receive the value of the vested interest in his or her account as a lump-sum distribution.

Expenses

        During 2002 and 2001, the Company paid all administrative expenses relating to the Plan except for certain fund level expenses that are offset against investment income prior to allocation to participant accounts. Effective January 1, 2003, the participants will pay all administrative expenses formerly paid by the Company.

Plan Termination

        While the Company has not expressed any intent to discontinue their contributions or terminate the Plan, they are free to do so at any time. In the event the Plan is terminated, the Plan provides that each participant's balance, inclusive of Company contributions, becomes immediately 100 percent vested and shall be distributed to the participants.

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B.    Investment Options

        During the plan years ended December 31, 2002 and 2001, participants were able to allocate their contributions among the following investment options:

C.    Summary of accounting policies

        The following accounting policies, which conform to accounting principles generally accepted in the United States of America, have been used consistently in the preparation of the Plan's financial statements:

Basis of Accounting

        The financial statements of the Plan are prepared under the accrual method of accounting.

Use of Estimates

        The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of additions and deductions during the reporting period. Actual results could differ from those estimates.

Investment Valuation and Income Recognition

        The Plan's investments are stated at fair value, except for its investment contract(s), which are valued at contract value which approximates fair value (Note E). Shares of White Mountains common stock and registered investment companies are valued at quoted market prices, which represent the net asset value of shares held by the Plan at year-end. Participant loans are valued at cost, which approximates fair value. Shares in common/collective trust funds are valued at the net asset value of

7

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the Plan's shares held, as determined by the Custodian. Purchases and sales of investments are recorded on a trade-date basis. Interest income is accrued when earned. Dividend income is recorded on the ex-dividend date. Capital gain distributions are included in dividend income.

        In accordance with the policy of stating investments at fair value, the Plan presents in the Statement of Changes in Net Assets Available for Benefits the net appreciation (depreciation) in the fair value of its investments which consists of the realized gains or losses and the unrealized appreciation (depreciation) on those investments.

Benefit Payments

        Benefits are recorded when paid.

Risks and Uncertainties

        The Plan provides various investment options in any combination of stocks, bonds, fixed income securities, mutual funds, money market funds, and other investment securities. Investment securities are exposed to various risks such as interest rate, market, and credit risks. Due to the level of risk associated with certain investment securities, and a level of uncertainty related to changes in the value of investment securities, it is at least reasonably possible that changes in risks in the near term would materially affect participants' account balances and the amounts reported in the Statement of Net Assets Available for Benefits and the Statement of Changes in Net Assets Available for Benefits.

D.    Investments

        The following presents the fair value of investments that represent 5 percent or more of the Plan's net assets.

        During 2002 and 2001, the Plan's investments (including gains and losses on investments bought and sold, as well as held during the year) appreciated/(depreciated) in value as follows:

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E.    Investment Contracts (OneBeacon Insurance Stable Value Fund)

        The Plan has entered into benefit-responsive investment contracts with AIG Life, CDC Capital, GE Life and Annuity Insurance, John Hancock Mutual, JP Morgan Chase Bank, Life of Virginia, Metropolitan Life Insurance, New York Life Insurance, Rabobank, State Street Bank, and Vanguard Prime Money Market Fund. These institutions maintain the contributions in a general account. The account is credited with earnings on the underlying investments and charged for participant withdrawals and administrative expenses. The contracts are included in the financial statements at contract value as reported to the Plan by these institutions. Contract value represents contributions made under the contracts, plus earnings, less participant withdrawals and administrative expenses. The average yields during the years ended December 31, 2002 and 2001 were 5.29 percent and 5.73 percent, respectively. The crediting interest rates ranged from 3.85 to 7.64 percent and 4.67 to 7.64 percent at December 31, 2002 and 2001, respectively. The crediting interest rate is based on a formula agreed upon with the issuer, but may not be less than 0 percent. Such interest rates on synthetic contracts are reviewed on a quarterly basis for resetting.

F.     Related party transactions

        The Plan invests in shares of mutual funds managed by an affiliate of Vanguard Fiduciary Trust Company ("VFTC"). VFTC acts as trustee for only those investments as defined by the Plan. The Plan also has investments, which are managed by White Mountain Advisors, an affiliate of the Company. Transactions in such investments qualify as party-in-interest transactions, which are exempt from the prohibited transaction rules. Participants' loans also constitute party-in-interest transactions.

        The Plan invests in the White Mountains Stock Fund (the "Fund") which is comprised of common shares of White Mountains Insurance Group, Ltd. (the Parent Company) and small amounts of cash invested in the Vanguard Prime Money Market Fund. The share values of the Fund are recorded and maintained by VFTC, Trustee of the Plan. During the years ended December 31, 2002 and 2001, the Plan purchased shares in the Fund in the amounts of $5,021,187 and $4,871,180, respectively, sold shares in the Fund of $2,652,396 and 145,861, respectively, and had net depreciation in the Fund of $(346,363) and $(2,134), respectively. The total value of the Plan's investment in the Fund was $6,745,613 and $4,723,185 at December 31, 2002 and 2001, respectively.

G.    Tax Status

        The Internal Revenue Service has determined and informed the Company by a letter dated January 16, 2002, that the Plan and related trust are designed in accordance with applicable sections of the Internal Revenue Code ("IRC"). Management believes the Plan is designed and operates in accordance with the IRC, therefore, no provision for income taxes is required.

H.    2002 Transfer Out

        Effective December 31, 2001, approximately 1,972 full time employees of the property and casualty business were transferred to Liberty Mutual. Employees with loan balances could either pay off their loan and remain in the Plan or transfer their loan and investments in their entirety to the Liberty Mutual Thrift Incentive Plan. In January 2002, $17,242,618 in loans and investments were transferred out of the Plan.

I.     2001 Transfer Out

        In connection with the sale of the Company on June 1, 2001, an affiliated group with participants in the Plan, CGU Life Insurance Company, was divested and the assets and obligations in the amount of $6,660,142 associated with these participants were transferred out to a newly created qualified plan, CGNU Service Corporation 401(k) Plan.

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OneBeacon Insurance Savings Plan

Schedule of Assets (Held at End of Year)

(Form 5500, Schedule H, Part IV, Line 4i)

IDENTITY OF ISSUE					SECURITY DESCRIPTION		CURRENT VALUE
Cash and cash equivalents
	*TBC INC POOLED EMPLOYEE FUNDS				DAILY LIQUIDITY FUND			9,281,071
Common Stock
	AETNA INC COM NEW				7,800		$	320,736
	ALEXANDER & BALDWIN INC				40,000			1,031,600
	AMERADA HESS CORP				10,000			550,500
	AMERICAN INTL GROUP INC				10,000			578,500
	AON CORP COM				80,000			1,511,200
	ARCHER DANIELS MIDLAND CO				50,000			620,000
	BANK ONE CORP				12,400			453,220
	BERKSHIRE HATHAWAY INC DEL CLASS B				500			1,211,500
	CAPITOL FED FINL				15,000			432,000
	COSTCO WHSL CORP				12,500			350,750
	EL PASO ELEC CO				160,000			1,760,000
	FAIRMONT HOTELS & RESORTS INC				100,000			2,355,000
	FIRST DATA CORP				12,000			424,920
	FIRSTENERGY CORP				100,000			3,297,000
	FPL GROUP INC				5,000			300,650
	GILLETTE CO				20,000			607,200
	GREAT LAKES CHEM CORP				110,000			2,626,800
	HASBRO INC				40,000			462,000
	HONEYWELL INTL INC				20,000			480,000
	LONGVIEW FIBRE CO				100,000			723,000
	MARATHON OIL CORP				130,000			2,767,700
	MATTEL INC				40,000			766,000
	MBNA CORP				33,300			633,366
	MCDONALDS CORP				10,000			160,800
	MEREDITH CORP				70,000			2,877,700
	MILLER HERMAN INC				13,700			252,080
	OCTEL CORP				60,000			948,000
	OVERSEAS SHIPHOLDING GROUP				30,000			537,000
	PEOPLES BANK				90,000			2,262,600
	POTLATCH CORP				30,000			716,400
	PRINCIPAL FINANCIAL GROUP				12,000			361,560
	RYDER SYS INC				50,000			1,122,000
	SAFEWAY INC				20,000			467,200
	SBC COMMUNICATIONS INC				20,000			542,200
	STANLEY WKS				13,000			449,540
	TEXAS INSTRUMENTS INC				12,000			180,120
	TJX COS INC				32,200			628,544
	TRAVELERS PROPERTY CASUALTY				25,000			366,250
	UNISOURCE ENERGY CORP				200,000			3,458,000
	UNITED PARCEL SVC INC CL B				11,000			693,880
	UNITED TECHNOLOGIES CORP				10,000			619,400
	UNOCAL CORP				25,000			764,500
	VIACOM INC CL B				10,260			418,198
	WASHINGTON MUTUAL INC				17,000			587,010
	WELLPOINT HEALTH NETWORK INC				10,000			711,600

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Preferred Stock
	ROUSE CO EXCH CVT PFD SER B				20,000			917,500
	UNION PAC CAP TR TERM INCOME				77,500			3,971,875
	UNOCAL CAP TR EXCH CVT PFD				75,000			3,834,375
Company Stock
	*WHITE MOUNTAINS STOCK				20,799			6,718,077
Corporate Bonds
	3M EMPLOYEE STK OWNERSHIP 144A				5.620% 07/15/2009			757,359
	AMERICAN GEN FIN MTN #TR00378				5.375% 10/01/2012			2,048,170
	AON CORP SR DEB CVT 144A				3.500% 11/15/2012			555,000
	CONOCO INC SR NTS				6.350% 04/15/2009			2,246,520
	DEERE & CO DEB				7.850% 05/15/2010			2,392,760
	DOVER CORP NT				6.450% 11/15/2005			1,105,210
	DU PONT EI DE NEMOURS & CO NT				6.875% 10/15/2009			2,352,940
	ECOLAB INC NT				6.875% 02/01/2011			544,970
	ELECTRONIC DATA SYS CORP NT				7.125% 10/15/2009			2,055,680
	FOSTERS FIN CORP NT 144A				6.875% 06/15/2011			1,139,989
	HARTFORD LIFE INC SR NT				7.375% 03/01/2031			1,113,650
	HARVARD UNIV MASS				8.125% 04/15/2007			1,243,550
	HEINZ H J FIN CO GTD NT 144A				6.625% 07/15/2011			2,267,090
	INTERNATIONAL PAPER CO				7.500% 05/15/2004			1,067,580
	KINDER MORGAN ENERGY SR NT				7.500% 11/01/2010			1,138,571
	LOEWS CORP SUB NOTES CVT				3.125% 09/15/2007			1,118,750
	MARSH & MCLENNAN COS INC				7.125% 06/15/2009			1,714,035
	MATTEL INC MTN # TR 00019				7.480% 04/22/2009			1,109,020
	NEWELL CO MTN #TR 00032				5.420% 10/21/2003			1,544,400
	OHIO CAS CORP NT CVT				5.000% 03/19/2022			461,875
	PEARSON INC GTD NT 144A				7.375% 09/15/2006			1,125,900
	RAILCAR TR NO 1992-1				7.750% 06/01/2004			165,122
	SARA LEE CORP MTN # TR 00020				6.275% 02/23/2004			1,571,745
	SOUTHWEST AIRLS 01-1 CL A2				5.496% 11/01/2006			1,162,018
	ST PAUL COS INC MTN # TR 00054				6.730% 07/14/2005			1,074,040
	STANDARD CR CARD 94-2 CTF CL A				7.250% 04/07/2006			2,269,902
	TECK COMINCO LTD CV SUB DEB				3.750% 07/15/2006			855,000
	TRIBUNE CO MTN #TR 00043				5.900% 01/24/2006			1,081,240
	TRIZEC HAHN CORP DEBS EXCH				3.000% 01/29/2021			1,661,250
	WELLPOINT HEALTH NETWORKS NT				6.375% 06/15/2006			1,091,754
	WELLS FARGO BK NA NT				6.450% 02/01/2011			2,245,180
US Government Securities
	FEDERAL HOME LN MTG CORP DEBS				7.800% 09/12/2016			1,162,881

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OneBeacon Insurance Group Stable Value Fund—Insurance and Investment Contracts
	AIG Life 1050				6.21% 4/30/2003			4,207,227
	CDC Capital 362-02				3.85% 12/2/2003
	Wrapper contract							661,977
		Underlying assets
			SBM7 1998-NC7 A7					4,353,053
			Total contract value					5,015,030
	CDC Capital 362-03				5.75% 2/8/2004
	Wrapper contract							4,776,479
		Underlying assets
			PBHET 1998-2 A5					1,279,845
			Total contract value					6,056,324
	CDC Financial Products 1362-01				4.26%
	Wrapper contract							(32,867	)
		Underlying assets
			*VFTC Intermediate-Term Trust					2,048,702
			Total contract value					2,015,835
	GE Life and Annuity GS-3328				6.77% 5/15/2004			2,501,642
	John Hancock Mutual GAC-14647				6.77% 7/15/2004			2,501,642
	JP Morgan Chase Bank JPMBEAC01				4.73%
	Wrapper contract							(207,173	)
		Underlying assets
			*VFTC Mortgage Backed Securities Trust					3,290,182
			*Vanguard Total Bond Market Index Fund					4,482,920
			Total contract value					7,565,929
	Life of Virginia GS-3216				5.45% 1/31/2003			2,009,911
	Metropolitan Life 25656				7.13% 5/15/2005			4,672,888
	Metropolitan Life 25855				5.93% 7/15/2005			2,213,278
	New York Life GA31132				7.64% 10/15/2004			4,817,552
	New York Life GA31132-002				6.29% 8/15/2005			4,521,292
	Rabobank GAC 099601				4.86%
	Wrapper contract							(481,067	)
		Underlying assets
			*VFTC Intermediate-Term Trust					11,921,657
			Total contract value					11,440,595
	Rabobank GAC 069701				4.90%
	Wrapper contract							(247,195	)
		Underlying assets
			*Vanguard Total Bond Market Index Fund					4,466,797
			Total contract value					4,219,602

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	State Street Bank 101049				5.08% 9/30/2007
	Wrapper contract							(541,556	)
		Underlying assets
			*Vanguard Targeted Return Trust (4-05)					2,358,868
			*Vanguard Targeted Return Trust (1-06)					1,753,529
			*Vanguard Targeted Return Trust (2-06)					1,744,075
			*Vanguard Targeted Return Trust (3-06)					1,542,053
			*Vanguard Targeted Return Trust (4-06)					1,548,859
			*Vanguard Targeted Return Trust (1-07)					1,554,053
			*Vanguard Targeted Return Trust (2-07)					1,557,047
			*Vanguard Targeted Return Trust (3-07)					1,565,216
			Total contract value					13,082,145
	*Vanguard Prime Money Market Fund				1.25%			4,237,391
Participant Loans
	*Participant Loans				5.25% — 11.7%			5,311,372
Registered Investment Companies
	Liberty Select Value Fund				408,755			7,729,550
	*Vanguard 500 Index Fund				310,250			25,176,783
	*Vanguard Asset Allocation Fund				359,830			6,502,131
	*Vanguard Extended Market Index Fund				386,670			7,246,201
	*Vanguard High-Yield Corp Fund				205,010			1,205,458
	*Vanguard Int'l Growth Fund				436,293			5,305,319
	*Vanguard LT Corporate Fund				1,080,195			9,970,198
	*Vanguard Morgan Growth Fund				39,907			444,965
	*Vanguard Prime Money Mkt Fund				17,618,456			17,618,456
	*Vanguard Small-Cap Index Fund				233,336			3,654,037
	*Vanguard ST Corporate Fund				331,905			3,581,255
	*Vanguard Total Int'l Stock Idx Fund				179,204			1,383,454
	*Vanguard U.S. Growth Fund				63,594			766,948
	*Vanguard Wellington Fund				811,386			19,927,651
	*Vanguard Windsor Fund				2,184,823			26,217,886
	*Vanguard Windsor II Fund				422,273			8,783,272
							$	343,457,492

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*

Denotes party-in-interest.

        Cost omitted for participant directed investments.

13

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Index of Financial Statements and Supplemental Schedule
Report of Independent Auditors
OneBeacon Insurance Savings Plan Statements of Net Assets Available for Benefits December 31, 2002 and 2001
OneBeacon Insurance Savings Plan Statements of Changes in Net Assets Available for Benefits For the years ended December 31, 2002 and 2001
OneBeacon Insurance Savings Plan
OneBeacon Insurance Savings Plan Schedule of Assets (Held at End of Year) (Form 5500, Schedule H, Part IV, Line 4i)

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Exhibit 99(B)

Consent of Independent Accountants

        We hereby consent to the incorporation by reference in the Registration Statement of White Mountains Insurance Group, Ltd. (Form S-8, No. 333-68438), of our report dated June 26, 2003 relating to the financial statements and supplemental schedule of OneBeacon Insurance Savings Plan as of and for the year ended December 31, 2002 included with this Form 11-K.

/s/ PricewaterhouseCoopers LLP
Boston, Massachusetts
June 26, 2003

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Consent of Independent Accountants

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Exhibit 99(C)

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

        In connection with the Annual Report of OneBeacon Insurance Savings Plan (the "Plan") on Form 11-K for the year ending December 31, 2002 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Mark R. Sturdevant, Manager Financial Reporting of OneBeacon Insurance Company, certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

•

The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and,



•

The information contained in the Report fairly presents, in all material respects, the financial condition and changes in net assets of the Plan as of and for the periods presented in the Report.

/s/ Mark R. Sturdevant
Manager Financial Reporting
(Principal Financial Officer)

Date: June 27, 2003

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CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

        In connection with the Annual Report of OneBeacon Insurance Savings Plan (the "Plan") on Form 11-K for the year ending December 31, 2002 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Thomas N. Schmitt, Senior Vice President, Human Resources of OneBeacon Insurance Company, certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

•

The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and,



•

The information contained in the Report fairly presents, in all material respects, the financial condition and changes in net assets of the Plan as of and for the periods presented in the Report.

/s/ Thomas N. Schmitt
Senior Vice President, Human Resources
(Principal Executive Officer)

Date: June 27, 2003

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CERTIFICATIONS