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                                                                 Exhibit 10(s)

FOLKSAMERICA HOLDING COMPANY, INC.
WHITE MOUNTAINS PERFORMANCE SHARE PLAN



1.   PURPOSE

     The purpose of the Folksamerica Holding Company Plan (the "Company" and the
     "Plan" respectively) is to advance the interests of White Mountains
     Insurance Group, Ltd. ("White Mountains") and its stockholders by providing
     long-term incentives to certain key executives of the Company and of its
     subsidiaries who perform services for White Mountains and its affiliates
     and subsidiaries from time to time.

2.   ADMINISTRATION

     The Plan shall be administered by the Board of Directors (the "Board") of
     the Company or a "Committee" of disinterested Directors of the Board in
     consultation with White Mountains executives.

     The Board in consultation with White Mountains shall have exclusive
     authority to select the employees of the Company to be granted Awards, to
     determine the type, size and terms of the Awards and to prescribe the form
     of the instruments embodying Awards. The Board shall be authorized to
     interpret the Plan and the Awards granted under the Plan, to establish,
     amend and rescind any rules and regulations relating to the Plan and to
     make any other determinations which it believes necessary or advisable for
     the administration of the Plan. The Board may correct any defect or supply
     any omission or reconcile any inconsistency in the Plan or in any Award in
     the manner and to the extent the Board deems desirable to carry it into
     effect. Any decision of the Board in the administration of the Plan, as
     described herein, shall be final and conclusive. The Board may act only by
     a majority of its members in office, except that the members thereof may
     authorize any one or more of their number or any officer of the Company to
     execute and deliver documents on behalf of the Board. No member of the
     Company shall be liable for anything done or omitted to be done by him or
     by any other member of the Board in connection with the Plan, except for
     his own willful misconduct or as expressly provided by statute.

3.   PERFORMANCE SHARES

     The Award of Performance Shares to a participant will entitle him to
     receive, without payment to the Company, all or part of a specified amount
     (the "Actual Value") as determined by the Board. Payment in respect of an
     Award shall be made as provided in subparagraph 3(e). Each Award of
     Performance Shares shall be subject to the following terms and conditions:

     (a) The Board shall determine the number of Performance Shares to be
         granted to each participant. The "Maximum Value" of each Performance
         Share shall be the market value per Share on the date the award is paid
         or becomes payable to participants. Performance Shares may be issued in
         different classes or series having different terms and conditions.


     (b) The award period (the "Award Period") in respect of any Award of
         Performance Shares shall be such periods as the Board shall determine
         commencing as of the beginning of the fiscal year of the Company in
         which such Award is made. At the time each Award is made, the Board
         shall establish performance objectives to be attained within the
         performance periods as the means of determining Actual Value. Subject
         to adjustment by the Board from Award Period to Award Period, such
         Award shall be based upon the economic performance target of White
         Mountains over a rolling three year performance period which Award
         shall be based upon the growth in economic value of White Mountains and
         to the extent deemed appropriate by the Board in their sole judgment,
         the economic return of Folksamerica. The Actual Value of



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         a Performance Share shall be equal to its Maximum Value only if the
         performance objectives are attained in full. In determining Actual
         Value, the Board shall multiply the total number of Shares available
         for payout at that time with respect to the participant by the Actual
         Value of each individual Share.

     (c) Performance Shares shall be cancelled if the participant's continuous
         employment with the Company or any of its subsidiaries shall terminate
         for any reason prior to the end of the Award Period, except solely by
         reason of a period of Related Employment as defined in paragraph 5, and
         except as otherwise specified in this subparagraph 3(c) or in
         subparagraph 3(d). Notwithstanding the foregoing and without regard to
         subparagraph 3(b), if a participant shall,

         (i)      while in such employment, die or become disabled as described
                  in paragraph 4 prior to the end of the Award Period, the
                  Performance Shares shall be cancelled at the end of the next
                  ending performance period and he, or his legal representative,
                  as the case may be, shall receive payment in respect of such
                  Shares which he would have received had he been in continuous
                  employment with the Company through the end of that period and
                  had the individual performance objectives, if any, that were
                  imposed been achieved; provided, however, that no such
                  continuation shall be deemed to have occurred for purposes of
                  applying subparagraph 3(d) in the event of an Adverse Change
                  in the Plan in respect of the participant following a Change
                  in Control; or

         (ii)     retire under an approved retirement program of the Company or
                  a subsidiary (or such other plan as may be approved by the
                  Board, in its sole discretion, for this purpose) prior to the
                  end of the Award Period, and

                  (A)      at the time of his retirement, the participant is 65
                           years old or older, the Performance Shares shall be
                           cancelled at the end of the next ending performance
                           period, and he shall receive the Maximum Value in
                           respect to such Shares, at the date of cancellation,

                  (B)      at the time of his retirement the participant is less
                           than 65 years old and his retirement occurs prior to
                           the end of the first performance period, and before
                           24 months have elapsed since the first day of the
                           Award Period, the participant shall receive payment
                           with respect to the Actual Value of one-ninth of the
                           Performance Shares awarded to him under the Award,
                           and

                  (C)      at the time of his retirement the participant is less
                           than 65 years old and his retirement occurs prior to
                           the end of the first performance period and after at
                           least 24 months have elapsed since the first day of
                           the Award Period, the participant shall receive
                           payment with respect to the Actual Value of
                           two-ninths of the Performance Shares awarded to him
                           under the Award.

     (d) If within 24 months after a Change in Control of the Company as defined
         in subparagraph 6(a) and prior to the end of an Award Period:

         (i)      there is a Termination Without Cause, as defined in paragraph
                  7, of the employment of a participant;

         (ii)     there is a Constructive Termination, as defined in paragraph
                  8, of the employment of a participant; or

         (iii)    there occurs an Adverse Change in the Plan, as defined in
                  paragraph 9, in respect of a participant, then:

                  (A)      the participant shall receive the Maximum Value of:


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                           (1)      that number of Performance Shares which is
                                    in the same proportion to the total number
                                    of Performance Shares awarded to the
                                    participant under such Award as

                                    (x)     the number of full months which have
                                            elapsed since the first day of the
                                            Award Period to the end of the first
                                            month in which occurs one of the
                                            events described in clauses (i),
                                            (ii) or (iii) of subparagraph 3(d)
                                            is to

                                    (y)     the total number of months in the
                                            Award Period, less

                           (2)      the number of Performance Shares awarded to
                                    the participant under the Award in respect
                                    of which payment has already been made to
                                    the participant, and

                  (B)      if the number of Performance Shares determined
                           pursuant to subclause (1) of clause (A) is less than
                           the number of Performance Shares subject to the
                           particular Award, the participant shall receive the
                           Actual Value of the remaining Performance Shares. The
                           Actual Value of the remaining Performance Shares
                           shall be determined as follows:

                           (x)      if the Board shall have determined, prior to
                                    the Change in Control and based on the most
                                    recent performance status reports, that the
                                    performance objectives for the particular
                                    Award were being met at the date of the
                                    determination, the Actual Value of the
                                    remaining Performance Shares subject to the
                                    particular Award shall be equal to their
                                    Maximum Value, and

                           (y)      if the determination of the Board was that
                                    the performance objectives for the
                                    particular Award were not being met at the
                                    date of the determination, the Actual Value
                                    of the remaining Performance Shares subject
                                    to the particular Award shall be such amount
                                    as shall have been determined by the Board
                                    as provided above in this subparagraph 3(d),
                                    but in no event shall Actual Value be less
                                    than fifty percent (50%) of Maximum Value.
                                    Payment of any amount in respect of
                                    Performance Shares as described above in
                                    this subparagraph 4(d) shall be made as
                                    promptly as possible after the occurrence of
                                    one of the events described in clauses
                                    3(d)(i) through 3(d)(iii). Notwithstanding
                                    anything herein to the contrary, if,
                                    following a Change in Control of the Company
                                    as defined in subparagraph 6(a), a
                                    participant's employment remains continuous
                                    through the end of a performance period,
                                    then the participant shall be paid with
                                    respect to those Performance Shares for
                                    which he would have been paid had there not
                                    been a Change in Control and the Actual
                                    Value of those Shares shall be determined in
                                    accordance with subparagraph 3(e).

     (e) Payment of any amount in respect of the Performance Shares shall be
         made by the Company as promptly as practicable or shall be deferred to
         such other time or times as the Board shall determine, and may be made
         in cash, in White Mountains Shares, or partly in cash and partly in
         White Mountains Shares as determined by the Board. Such deferred
         payments may be made by undertaking to pay cash in the future, together
         with such additional amounts as may accrue thereon until the date or
         dates of payment, as determined by the Board in its discretion.


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4.   DISABILITY


     For the purposes of this Plan, a participant shall be deemed to be disabled
     if the Board shall determine that the physical or mental condition of the
     participant is such as would entitle him to payment of monthly disability
     benefits under any disability plan of the Company or a subsidiary in which
     he is a participant .

5.   RELATED EMPLOYMENT

     For the purposes of this Plan, Related Employment shall mean the employment
     of an individual by an employer which is neither the Company nor a
     subsidiary provided: (i) such employment is undertaken by the individual
     and continued at the request of the Company or a subsidiary; (ii)
     immediately prior to undertaking such employment, the individual was an
     officer or employee of the Company or a subsidiary, or was engaged in
     Related Employment as herein defined; and (iii) such employment is
     recognized by the Board, in its sole discretion, as Related Employment for
     the purposes of this paragraph 6. The death or disability of an individual
     during a period of Related Employment as herein defined shall be treated,
     for purposes of this Plan, as if the death or onset of disability had
     occurred while the individual was an officer or employee of the Company.

6.   CHANGE IN CONTROL

     (a) For purposes of this Plan, a "Change in Control of White Mountains or
         the Company" within the meaning of this subparagraph 7(a) shall occur
         if:

         (i)      Any person or group (within the meaning of Section 13(d) and
                  14(d)(2) of the Exchange Act), other than John J. Byrne,
                  Berkshire Hathaway, Inc. or one of its wholly owned
                  subsidiaries, becomes the beneficial owner (within the meaning
                  of Rule 13d-3 under the Exchange Act) of thirty-five percent
                  (35%) or more of the White Mountains' then outstanding Shares
                  or fifty percent (50%) or more of the then outstanding shares
                  of the Company;

         (ii)     the Continuing Directors, as defined in subparagraph 6(b),
                  cease for any reason to constitute a majority of the Board of
                  White Mountains; or

         (iii)    the business of the Company for which the participant's
                  services are principally performed is disposed of by White
                  Mountains pursuant to a sale or other disposition of all or
                  substantially all of the business or business related assets
                  of the Company (including stock of a subsidiary of the
                  Company).

     (b) For the purposes of this Plan, "Continuing Director" shall mean a
         member of the White Mountains Board (A) who is not an employee of the
         Company or its subsidiaries or of a holder of, or an employee or an
         affiliate of an entity or group that holds, thirty-five percent (35%)
         or more of the Company's Shares and (B) who either was a member of the
         Board on September 4, 1985, or who subsequently became a director of
         the Company and whose election, or nomination for election, by the
         Company's shareholders was approved by a vote of a majority of the
         Continuing Directors then on the Board (which term, for purposes of
         this definition, shall mean the whole Board and not any Board thereof).
         Any action, approval of which shall require the approval of a majority
         of the Continuing Directors, may be authorized by one Continuing
         Director, if he is the only Continuing Director on the Board, but no
         such action may be taken if there are not Continuing Directors on the
         Board.

7.   TERMINATION WITHOUT CAUSE


     For purposes of this Plan, "Termination Without Cause" shall mean a
     termination of the participant's employment with the Company or a
     subsidiary by the Company or the subsidiary other than (i) for disability
     as described in paragraph 4 or (ii) for Cause. "Cause" shall mean (a) an
     act or omission by the participant that constitutes a felony or any crime
     involving moral turpitude; or (b) willful gross negligence or willful gross


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     misconduct by the participant in connection with his employment by the
     Company or by a subsidiary which causes, or is likely to cause, material
     loss or damage to the Company. Notwithstanding anything herein to the
     contrary, if the participant's employment with the Company or one of its
     subsidiaries shall terminate due to a Change in Control of the Company as
     described in Subsection 6(a)(iii), where the purchaser, as described in
     such subsection, formally assumes the Company's obligations under this Plan
     or places the participant in a similar or like plan with no diminution of
     the value of the awards, such termination shall not be deemed to be a
     "Termination Without Cause."

8.   CONSTRUCTIVE TERMINATION

     "Constructive Termination" shall mean a termination of employment with the
     Company or a subsidiary at the initiative of the participant that the
     participant declares by prior written notice delivered to the Secretary of
     the Company to be a Constructive Termination by the Company or a subsidiary
     and which follows (a) a material decrease in his salary or (b) a material
     diminution in the authority, duties or responsibilities of his position
     with the result that the participant makes a determination in good faith
     that he cannot continue to carry out his job in substantially the same
     manner as it was intended to be carried out immediately before such
     diminution. Notwithstanding anything herein to the contrary, Constructive
     Termination shall not occur within the meaning of this paragraph 9 until
     and unless 30 days have elapsed from the date the Company receives such
     written notice without the Company curing or causing to be cured the
     circumstance or circumstances described in this paragraph 9 on the basis of
     which the declaration of Constructive Termination is given.

9.   ADVERSE CHANGE IN THE PLAN

     An "Adverse Change in the Plan" shall mean

     (a) termination of the Plan pursuant to subparagraph 14(a);

     (b) amendment of the Plan pursuant to paragraph 13 that materially
         diminishes the value of Awards that may be granted under the Plan,
         either to individual participants or in the aggregate, unless there is
         substituted concurrently authority to grant long-term incentive awards
         of comparable value to individual participants in the Plan or in the
         aggregate, as the case may be; or

     (c) in respect of any holder of an Award a material diminution in his
         rights held under such Award (except as may occur under the terms of
         the Award as originally granted) unless there is substituted
         concurrently a long-term incentive award with a value at least
         comparable to the loss in value attributable to such diminution in
         rights.

10.  DILUTION AND OTHER ADJUSTMENTS

     In the event of any change in the Outstanding Shares of White Mountains by
     reason of any stock split, stock dividend, recapitalization, merger,
     consolidation, reorganization, combination or exchange of Shares or other
     similar event, and if the Board shall determine, in its sole discretion,
     that such change equitably requires an adjustment in the number or kind of
     Shares that may be issued under the Plan, in the number or kind of Shares
     subject to, or the Stock Option price per share under, any outstanding
     Stock Option, in the number or kind of Shares which have been awarded as
     Restricted Stock or in the repurchase option price per share relating
     thereto, in the number of Maximum Value or Actual Value of Performance
     Shares which have been awarded to any participant, or in any measure of
     performance, then such adjustment shall be made by the Board and shall be
     conclusive and binding for all purposes of the Plan.

11.  DESIGNATION OF BENEFICIARY BY PARTICIPANT

     A participant may name a beneficiary to receive any payment to which he may
     be entitled in respect of


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     Performance Shares under the Plan in the event of his death, on a form to
     be provided by the Board. A participant may change his beneficiary from
     time to time in the same manner. If no designated beneficiary is living on
     the date on which any amount becomes payable to a participant's executors
     or administrators, the term "beneficiary" as used in the Plan shall include
     such person or persons.

12.  MISCELLANEOUS PROVISIONS

     (a) No employee or other person shall have any claim or right to be granted
         an Award under the Plan. Neither the Plan nor any action taken
         hereunder shall be construed as giving an employee any right to be
         retained in the employ of the Company or any subsidiary.

     (b) A participant's rights and interest under the Plan may not be assigned
         or transferred in whole or in part either directly or by operation of
         law or otherwise (except in the event of a participant's death),
         including but not limited to, execution, levy, garnishment, attachment,
         pledge, bankruptcy or in any other manner and no such right or interest
         of any participant in the Plan shall be subject to any obligation or
         liability or such participant.

     (c) No Shares shall be issued hereunder unless counsel for the Company
         shall be satisfied that such issuance will be in compliance with
         applicable Federal and state securities laws and Bermuda law.

     (d) The Company and its subsidiaries shall have the right to deduct from
         any payment made under the Plan any federal, state or local income or
         other taxes required by law to be withheld with respect to such
         payment. Notwithstanding anything in this Plan to the contrary, if the
         Company is unable to take a tax deduction for any period for which the
         Award is otherwise paid by reason of Section 162(m) of the Code, then
         in such event, such Award shall be deferred to the participants account
         as part of the Company Deferred Compensation Plan. It shall be a
         condition to the obligation of the Company to pay a Performance Share
         that the participant pay any and all withholding taxes upon demand of
         the Company, in such amounts as may be required by the Company for the
         purpose of satisfying any liability to withhold Federal, state or local
         income or other taxes of the participant. If the amount requested is
         not paid, the Company may refuse to make payment.

     (e) The expenses of the Plan shall be borne by the Company. However, if an
         Award is made to an employee of a subsidiary:

         (i)      if such Award results in payment of cash to the participant,
                  such subsidiary shall pay to the Company an amount equal to
                  such cash payment; and

         (ii)     if the Award results in the issuance to the participant of
                  Shares, such subsidiary shall pay to the Company an amount
                  equal to fair market value thereof, as determined by the
                  Board, on the date such Shares are issued (or, in the case of
                  issuance of Restricted Stock or of Shares subject to transfer
                  and forfeiture conditions, equal to the fair market value
                  thereof on the date on which such Shares are no longer subject
                  to applicable restriction), minus the amount, if any received
                  by the Company in exchange for such Shares.

     (f) The Plan shall be unfunded. The Company shall not be required to
         establish any special or separate fund or to make any other segregation
         of assets to assure the payment of any Award under the Plan.

     (g) By accepting any Award or other benefit under the Plan, each
         participant and each person claiming under or through him shall be
         conclusively deemed to have indicated his acceptance and ratification
         of, and consent to, any action taken under the Plan by the Company, the
         Board or the Board.


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13.  AMENDMENT


     The Plan may be amended at any time and from time to time by the Board, but
     no amendment which increases the aggregate number of Shares which may be
     issued pursuant to the Plan or the class of employees eligible to
     participate shall be effective unless and until the same is approved by the
     shareholders of the Company. No amendment of the Plan shall adversely
     affect any right of any participant with respect to any Award previously
     granted without such participant's written consent.




14.  TERMINATION

     This Plan shall terminate upon the earlier of the following dates or events
to occur:

     (a) the adoption of a resolution of the Board terminating the Plan; or

     (b) ten years from the date the Plan is initially or subsequently approved
         and adopted by the shareholders of the Company.

     No termination of the Plan shall alter or impair any of the rights or
     obligations of any person, without his consent, under any Award previously
     granted under the Plan.


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