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

                                    FORM 13F
                               FORM 13F COVER PAGE

       INFORMATION REQUIRED OF INSTITUTIONAL INVESTMENT MANAGERS PURSUANT
  TO SECTION 13(F) OF THE SECURITIES EXCHANGE ACT OF 1934 AND RULES THEREUNDER

        Report for the Calendar Year or Quarter Ended DECEMBER 31 , 2002.


Check here if Amendment;  / /           Amendment Number:
This Amendment (Check only one):                  / / is a restatement.
                                                  / / adds new holdings entries.

Institutional Investment Manager Filing this Report:

Name:                                   White Mountains Insurance Group, Ltd.
Address of Principal Executive Office:  28 Gates Street
                                        White River Junction, Vermont 05001-7066
                                        U.S.A.

Form 13F File Number:                   028-01681

The institutional investment manager filing this report and the person by whom
it is signed hereby represent that the person signing the report is authorized
to submit it, that all information contained therein is true, correct and
complete, and that it is understood that all required items, statements,
schedules, lists, and tables, are considered integral parts of this form.

Person Signing this Report on Behalf of Reporting Manager:

Name:      J. Brian Palmer
Title:     Chief Accounting Officer
Phone:     (802) 295-4500

Signature, Place, and Date of Signing:

/s/ J. Brian Palmer    White River Junction, Vermont    February 14, 2003
- --------------------  -------------------------------  -------------------

[Signature]                 [City, State]                    [Date]


Report Type (Check only one):
/ /      13F HOLDINGS REPORT. (Check here if all holdings of this reporting
         manager are reported in this report.)

/ /      13F NOTICE. (Check here if no holdings reported are in this report, and
         all holdings are reported by other reporting manager(s).)

/X/      13F COMBINATION REPORT. Check here if a portion of the holdings for
         this reporting manager are reported in this report and a portion are
         reported by other reporting manager(s).)

List of Other Managers Reporting for this Manager:

Form 13F File Number                      Name
028-06739                                 High Rise Capital Management, L.P.




                              FORM 13F SUMMARY PAGE


Report Summary:

                                                 
Number of Other Included Managers:                        2
                                                    -------------

Form 13F Information Table Entry Total:                68 ITEMS
                                                    -------------

Form 13F Information Table Value Total:              $278,736,587
                                                    -------------
List of Other Included Managers: Provide a numbered list of the names and Form 13F file number(s) of all institutional investment managers with respect to which this report is filed, other than the manager filing this report. No. Form 13F File Number Name 1. 028-07388 Folksamerica Holding Company, Inc. --------- ---------------------------------- 2. 028-00470 OneBeacon Asset Management, Inc. --------- -------------------------------- WHITE MOUNTAINS INSURANCE GROUP, LTD. FORM 13F INFORMATION TABLE - DECEMBER 31, 2002
------------------------------------------------------------------------------------------------------------------------------ Amount Title CUSIP Market and Type Investment Name of Issuer of Class Number Value of Security Discretion Managers * ------------------------------------------------------------------------------------------------------------------------------ 1 BANK OF BERMUDA LTD SHS G07644100 243,174 7,623 DEFINED 1, 3 2 EVEREST RE GROUP LTD COM G3223R108 243,320 4,400 DEFINED 1, 3 3 PLATINUM UNDERWRITERS HOLDINGS COM G7127P100 210,800 8,000 DEFINED 1, 3 4 AEGON N V ORD AMER REG 007924103 178,337 13,900 DEFINED 1, 3 5 ALEXANDER & BALDWIN INC COM 014482103 4,384,300 170,000 DEFINED 2, 3 6 ALEXANDER & BALDWIN INC COM 014482103 515,800 20,000 DEFINED 1, 3 7 ALLEGHANY CORP DEL COM 017175100 510,426 2,876 DEFINED 1, 3 8 AMERADA HESS COM 023551104 17,616,000 320,000 DEFINED 2, 3 9 AMERADA HESS COM 023551104 1,651,500 30,000 DEFINED 1, 3 10 AON CORP COM 037389103 9,161,650 485,000 DEFINED 2, 3 11 AON CORP COM 037389103 2,507,459 132,740 DEFINED 1, 3 12 ARCHER DANIELS MIDLAND COM 039483102 2,446,000 200,000 DEFINED 2, 3 13 ARCHER DANIELS MIDLAND COM 039483102 366,900 30,000 DEFINED 1, 3 14 BISYS GROUP INC COM 055472104 160,908 10,120 DEFINED 1, 3 15 BANK OF HAWAII CORP COM 062540109 483,201 15,900 DEFINED 1, 3 16 BERKLEY, WR CORP COM 084423102 350,549 8,850 DEFINED 1, 3 17 BERKSHIRE HATHAWAY INC CL A 084670108 7,566,000 104 DEFINED 2, 3 18 BERKSHIRE HATHAWAY INC CL B 084670207 4,846,000 2,000 DEFINED 2, 3 19 BERKSHIRE HATHAWAY INC CL B 084670207 1,264,806 522 DEFINED 1, 3 20 CABLE & WIRELESS PLC SPONSORED ADR 126830207 116,500 50,000 DEFINED 2, 3 21 CAPITOL FEDERAL FINANCIAL COM 14057C106 2,448,000 85,000 DEFINED 2, 3 22 CAPITOL FEDERAL FINANCIAL COM 14057C106 720,000 25,000 DEFINED 1, 3 23 CHARTER FINANCIAL CORP COM 16122M100 326,350 10,700 DEFINED 2, 3 24 CITIGROUP INC COM 172967101 753,066 21,400 DEFINED 1, 3 25 COUNTRYWIDE CREDIT INDUSTRIES COM 222372104 619,800 12,000 DEFINED 1, 3 26 EL PASO ELECTRIC CO COM NEW 283677854 14,614,750 1,325,000 DEFINED 2, 3 27 EL PASO ELECTRIC CO COM NEW 283677854 1,824,362 165,400 DEFINED 1, 3 28 FAIRMONT HOTELS & RESORTS COM 305204109 4,710,000 200,000 DEFINED 2, 3 29 FIDELITY NATIONAL FINANCIAL INC COM 316326107 660,868 20,130 DEFINED 1, 3 30 FIRST DATA CORP COM 319963104 315,149 8,900 DEFINED 1, 3 31 FIRSTENERGY CORP COM 337932107 21,430,500 650,000 DEFINED 2, 3 32 FORTUNE BRANDS INC. COM 349631101 5,056,700 110,000 DEFINED 2, 3 33 GREAT LAKES CHEMICAL CORP COM 390568103 19,701,000 825,000 DEFINED 2, 3 34 GREAT LAKES CHEMICAL CORP COM 390568103 716,400 30,000 DEFINED 1, 3 35 HASBRO INC COM 418056107 2,220,000 200,000 DEFINED 2, 3 36 INTL SPEEDWAY CORP CL A 460335201 222,248 5,960 DEFINED 1, 3 37 INTUIT INC COM 461202103 201,756 4,300 DEFINED 1, 3 38 LAFARGE NORTH AMERICA INC COM 505862102 422,451 12,860 DEFINED 1, 3 39 LANDAMERICA FINANCIAL GROUP COM 514936103 319,405 9,010 DEFINED 1, 3 40 LONGVIEW FIBRE CO COM 543213102 3,976,500 550,000 DEFINED 2, 3 41 LONGVIEW FIBRE CO COM 543213102 216,900 30,000 DEFINED 1, 3 42 MARATHON OIL CORP COM 565849106 22,141,600 1,040,000 DEFINED 2, 3 43 MARATHON OIL CORP COM 565849106 1,260,368 59,200 DEFINED 1, 3 44 MCDONALDS CORP COM 580135101 2,572,800 160,000 DEFINED 2, 3 45 MCDONALDS CORP COM 580135101 321,600 20,000 DEFINED 1, 3 46 MEREDETH CORP COM 589433101 17,307,500 430,000 DEFINED 2, 3 47 MEREDETH CORP COM 589433101 603,750 15,000 DEFINED 1, 3 48 MERRILL LYNCH & CO INC COM 590188108 356,730 9,400 DEFINED 1, 3 49 MORGAN STANLEY COM NEW 617446448 487,024 12,200 DEFINED 1, 3 50 OCTEL CORP COM 675727101 19,118,000 1,210,000 DEFINED 2, 3 51 OCTEL CORP COM 675727101 395,000 25,000 DEFINED 1, 3 52 OVERSEAS SHIPPING GROUP COM 690368105 3,669,500 205,000 DEFINED 2, 3 53 OVERSEAS SHIPPING GROUP COM 690368105 268,500 15,000 DEFINED 1, 3 54 PAULA FINANCIAL COM 703588103 292,361 423,712 DEFINED 2, 3 55 PEOPLES BANK COM 710198102 13,326,000 530,000 DEFINED 2, 3 56 PEOPLES BANK COM 710198102 630,000 25,000 DEFINED 1, 3 57 POTLATCH CORPORATION COM 737628107 8,358,000 350,000 DEFINED 2, 3 58 POTLATCH CORPORATION COM 737628107 477,600 20,000 DEFINED 1, 3 59 R.H. DONNELLEY CORP COM NEW 74955W307 332,375 11,340 DEFINED 1, 3 60 RYDER SYSTEM COM 783549108 14,388,000 660,000 DEFINED 2, 3 61 RYDER SYSTEM COM 783549108 1,090,000 50,000 DEFINED 1, 3 62 SAFETY INSURANCE GROUP INC COM 78648T100 165,370 11,500 DEFINED 1, 3 63 UICI COM 902737105 495,112 31,840 DEFINED 1, 3 64 UNISOURCE ENERGY CORP. HLD. CO COM 909205106 27,058,850 1,565,000 DEFINED 2, 3 65 UNISOURCE ENERGY CORP. HLD. CO COM 909205106 2,387,749 138,100 DEFINED 1, 3 66 UNOCAL CORP COM 915289102 3,975,400 130,000 DEFINED 2, 3 67 UNOCAL CORP COM 915289102 458,700 15,000 DEFINED 1, 3 68 WACHOVIA CORP COM 929903102 498,864 13,690 DEFINED 1, 3 ------------------------------------------------------------------------------ Voting Authority (Shares) --------------------------------------------- Name of Issuer Sole Shared None ------------------------------------------------------------------------------ 1 BANK OF BERMUDA LTD 7,623 2 EVEREST RE GROUP LTD 4,400 3 PLATINUM UNDERWRITERS HOLDINGS 8,000 4 AEGON N V 13,900 5 ALEXANDER & BALDWIN INC 170,000 6 ALEXANDER & BALDWIN INC 20,000 7 ALLEGHANY CORP DEL 2,876 8 AMERADA HESS 320,000 9 AMERADA HESS 30,000 10 AON CORP 485,000 11 AON CORP 132,740 12 ARCHER DANIELS MIDLAND 200,000 13 ARCHER DANIELS MIDLAND 30,000 14 BISYS GROUP INC 10,120 15 BANK OF HAWAII CORP 15,900 16 BERKLEY, WR CORP 8,850 17 BERKSHIRE HATHAWAY INC 104 18 BERKSHIRE HATHAWAY INC 2,000 19 BERKSHIRE HATHAWAY INC 522 20 CABLE & WIRELESS PLC 50,000 21 CAPITOL FEDERAL FINANCIAL 85,000 22 CAPITOL FEDERAL FINANCIAL 25,000 23 CHARTER FINANCIAL CORP 10,700 24 CITIGROUP INC 21,400 25 COUNTRYWIDE CREDIT INDUSTRIES 12,000 26 EL PASO ELECTRIC CO 1,325,000 27 EL PASO ELECTRIC CO 165,400 28 FAIRMONT HOTELS & RESORTS 200,000 29 FIDELITY NATIONAL FINANCIAL INC 20,130 30 FIRST DATA CORP 8,900 31 FIRSTENERGY CORP 650,000 32 FORTUNE BRANDS INC. 110,000 33 GREAT LAKES CHEMICAL CORP 825,000 34 GREAT LAKES CHEMICAL CORP 30,000 35 HASBRO INC 200,000 36 INTL SPEEDWAY CORP 5,960 37 INTUIT INC 4,300 38 LAFARGE NORTH AMERICA INC 12,860 39 LANDAMERICA FINANCIAL GROUP 9,010 40 LONGVIEW FIBRE CO 550,000 41 LONGVIEW FIBRE CO 30,000 42 MARATHON OIL CORP 1,040,000 43 MARATHON OIL CORP 59,200 44 MCDONALDS CORP 160,000 45 MCDONALDS CORP 20,000 46 MEREDETH CORP 430,000 47 MEREDETH CORP 15,000 48 MERRILL LYNCH & CO INC 9,400 49 MORGAN STANLEY 12,200 50 OCTEL CORP 1,210,000 51 OCTEL CORP 25,000 52 OVERSEAS SHIPPING GROUP 205,000 53 OVERSEAS SHIPPING GROUP 15,000 54 PAULA FINANCIAL 423,712 55 PEOPLES BANK 530,000 56 PEOPLES BANK 25,000 57 POTLATCH CORPORATION 350,000 58 POTLATCH CORPORATION 20,000 59 R.H. DONNELLEY CORP 11,340 60 RYDER SYSTEM 660,000 61 RYDER SYSTEM 50,000 62 SAFETY INSURANCE GROUP INC 11,500 63 UICI 31,840 64 UNISOURCE ENERGY CORP. HLD. CO 1,565,000 65 UNISOURCE ENERGY CORP. HLD. CO 138,100 66 UNOCAL CORP 130,000 67 UNOCAL CORP 15,000 68 WACHOVIA CORP 13,690
* 1 = Folksamerica Holding Company, Inc. (Form 13F filed separately) * 2 = One Beacon Asset Management, Inc. (Form 13F filed separately) * 3 = White Mountains Insurance Group, Ltd.