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                                                                   EXHIBIT 10.18

                 FORM OF 100% QUOTA SHARE RETROCESSION AGREEMENT
                              (NON-TRADITIONAL D-1)

                                 BY AND BETWEEN

                        MOUNTAIN RIDGE INSURANCE COMPANY

                                  (RETROCEDANT)

                                       and

                     PLATINUM UNDERWRITERS REINSURANCE INC.

                               (RETROCESSIONAIRE)

                           DATED AS OF ________, 2002

     THIS QUOTA SHARE RETROCESSION AGREEMENT (this "AGREEMENT"), effective as of
12:01 a.m. New York time on the later of the Business Day (such term and all
other capitalized terms used but not defined herein shall have the meanings
ascribed to such terms in the Formation and Separation Agreement) following the
Closing or July 1, 2002 (the "EFFECTIVE TIME", and such date the "EFFECTIVE
DATE"), is made by and between MOUNTAIN RIDGE INSURANCE COMPANY, a Vermont
domiciled insurance company ("RETROCEDANT"), and PLATINUM UNDERWRITERS
REINSURANCE INC. (formerly known as USF&G Family Insurance Company), a Maryland
domiciled stock insurance company ("RETROCESSIONAIRE").

     WHEREAS, pursuant to a Formation and Separation Agreement dated as of [ ],
2002 (the "FORMATION AND SEPARATION AGREEMENT") between Platinum Underwriters
Holdings, Ltd. ("PLATINUM HOLDINGS"), the ultimate parent of Retrocessionaire
and The St. Paul Companies, Inc. ("THE ST. PAUL"), the ultimate parent of
Retrocedant, Platinum Holdings acquired one hundred percent (100%) of the issued
and outstanding Shares; and

     WHEREAS, pursuant to the Formation and Separation Agreement, The St. Paul
agreed to cause its insurance subsidiaries to cede specified liabilities under
certain reinsurance contracts of The St. Paul's insurance subsidiaries; and
Platinum Holdings agreed to cause its insurance subsidiaries to reinsure such
liabilities; and

     WHEREAS, Retrocedant has agreed to retrocede to Retrocessionaire, and
Retrocessionaire has agreed to assume by indemnity reinsurance, as of the
Effective

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Time, a one hundred percent (100%) quota share of the liabilities arising
pursuant to the Reinsurance Contract (as defined hereunder), subject to the
terms set forth herein.

     NOW, THEREFORE, in consideration of the mutual covenants and promises and
upon the terms and conditions set forth herein, the parties hereto agree as
follows:

                                    ARTICLE I

                                BUSINESS COVERED

     Retrocedant hereby obligates itself to retrocede to Retrocessionaire and
Retrocessionaire hereby obligates itself to accept, pursuant to the terms of
this Agreement, a one hundred percent (100%) quota share of any and all
liabilities incurred by Retrocedant under contracts effective on or after
January 1, 2002 but not yet paid as of the Effective Time, under the Multi-Year
Aggregate Excess of Loss Reinsurance Agreement with Company D (the "REINSURANCE
CONTRACT") for the period from January 1, 2002 through December 31, 2002.

                                   ARTICLE II

                                      TERM

     This Agreement shall be continuous as to the Reinsurance Contract. Except
as mutually agreed in writing by the Retrocedant and the Retrocessionaire, this
Agreement shall remain continuously in force until the Reinsurance Contract is
terminated, expired, cancelled or commuted.

                                   ARTICLE III

                                    COVERAGE

     SECTION 3.01   SECTION A (RETROSPECTIVE) COVERAGE PERIOD. The Section A
(Retrospective) Coverage Period will be the period from and including
January 1, 2002 to but not including the Effective Time.

     SECTION 3.02   SECTION B (PROSPECTIVE) COVERAGE PERIOD. The Section B
(Prospective) Coverage Period will be the period from and including the
Effective Time through the commutation, expiration, or final settlement of all
liabilities under any Reinsurance Contract.

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                                   ARTICLE IV

                      PREMIUMS AND ADDITIONAL CONSIDERATION

     SECTION 4.01   SECTION A (RETROSPECTIVE) COVERAGE PERIOD -- PREMIUM.

     (a)  On the Effective Date, in respect of the Section A (Retrospective)
Coverage Period, Retrocedant shall pay to the account of Retrocessionaire an
amount (the "INITIAL SECTION A PREMIUM") equal to one hundred percent (100%) of
the carrying value on the books of the Retrocedant as of June 30, 2002, of the
aggregate of all loss and loss adjustment expense and ceding commission reserves
relating to the Reinsurance Contract, with respect to the Section A
(Retrospective) Coverage Period, determined in accordance with statutory
accounting principles on a basis consistent in all material respects with the
methods, principles, practices and policies employed in the preparation and
presentation of Retrocedant's annual statutory financial statement as of
December 31, 2001 as filed with the Vermont Department of Insurance and as
submitted to The St. Paul, and subject to the adjustments as set forth on
Exhibit A hereto (the "LOSS RESERVE ADJUSTMENTS"), as applicable.

     (b)  As soon as reasonably practicable, but in no event later than 75 days
following the Effective Date, Retrocedant shall prepare and deliver to
Retrocessionaire an accounting, including the calculation of all Loss Reserve
Adjustments as provided for herein (the "PROPOSED LOSS RESERVE ACCOUNTING") of
all loss and loss adjustment expense reserves and ceding commission reserves
relating to the Reinsurance Contract, with respect to the Section A
(Retrospective) Coverage Period, as of the Effective Date, determined in
accordance with statutory accounting principles on a basis consistent in all
material respects with the methods, principles, practices and policies employed
in the preparation and presentation of Retrocedant's annual statutory financial
statement as of December 31, 2001 as filed with the Vermont Department of
Insurance and as submitted to The St. Paul, adjusted to reflect the Loss Reserve
Adjustments, as applicable (the "FINAL SECTION A PREMIUM"). In the event the
Final Section A Premium is greater than the Initial Section A Premium,
Retrocedant shall promptly pay to the account of Retrocessionaire the difference
plus interest on such amount at the Applicable Rate (as defined below) from and
including the Effective Date to and including the date of such payment. In the
event the Initial Section A Premium is greater than the Final Section A Premium,
Retrocessionaire shall promptly pay to the account of Retrocedant the difference
plus interest on such amount of the Applicable Rate from and including the
Effective Date to and including the date of such payment.

     SECTION 4.02   SECTION B (PROSPECTIVE) COVERAGE PERIOD -- PREMIUMS.

     (a)  On the Effective Date, in respect of the Section B (Prospective)
Coverage, Retrocedant shall transfer to Retrocessionaire an amount (the "INITIAL
SECTION B PREMIUM") equal to the carrying value on the books of Retrocedant as
of June 30, 2002 of one hundred percent (100%) of the unearned premium reserves
relating to the Reinsurance Contract for the Section B Coverage Period,
determined in accordance with statutory accounting principles on a basis
consistent in all material respects with the

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methods, principles, practices and policies employed in the preparation and
presentation of Retrocedant's annual statutory financial statement as of
December 31, 2001 as filed with the Vermont Department of Insurance and as
submitted to The St. Paul, less the applicable Ceding Commission, as defined
below, and with respect to the Reinsurance Contract, one hundred percent (100%)
of all gross premiums written on or after the Effective Time, net of premium
returns, allowances and cancellations, and less any applicable Ceding
Commission.

     (b)  As soon as reasonably practicable, but in no event later than 75 days
following the Effective Date, Retrocedant shall prepare and deliver to
Retrocessionaire an accounting (the "PROPOSED PREMIUM RESERVE ACCOUNTING",
together with the Proposed Loss Reserve Accounting, the "PROPOSED ACCOUNTING")
of all unearned premium reserves relating to the Reinsurance Contract for the
Section B (Prospective) Coverage Period, as of the Effective Date, determined in
accordance with statutory accounting principles on a basis consistent in all
material respects with the methods, principles, practices and policies employed
in the preparation and presentation of Retrocedant's annual statutory financial
statement as of December 31, 2001 as filed with the Vermont Department of
Insurance and as submitted to The St. Paul, relating to the Reinsurance
Contract, net of the applicable Ceding Commission (the "FINAL SECTION B
PREMIUM"). In the event the Final Section B Premium is greater than the Initial
Section B Premium, Retrocedant shall promptly pay to the account of
Retrocessionaire the difference plus interest on such amount at the Applicable
Rate from and including the Effective Date to and including the date of such
payment. In the event the Initial Section B Premium is greater than the Final
Section B Premium, Retrocessionaire shall promptly pay to the account of
Retrocedant the difference plus interest on such amount at the Applicable Rate
from and including the Effective Date to and including the date of such payment.

     (c)  Notwithstanding the foregoing, the parties agree that all gross
estimated premiums written prior to the Effective Date and earned but not yet
billed ("EBUB", and also referred to as "estimated premiums receivable" or
"EBNR") as of the Effective Time and relating to the Reinsurance Contracts, as
determined on or before _____, 2002, in accordance with Retrocedant's customary
practices and procedures and as submitted to The St. Paul, shall be allocated to
Retrocedant. All payments received after the Effective Time by Retrocedant or
Retrocessionaire in respect of EBUB as of the Effective Time shall be retained
by or transferred to Retrocedant, and all rights to collect such amounts shall
be retained by or transferred to Retrocedant. Any changes made on or after the
Effective Time as to the amount of EBUB as of the Effective Time shall be for
the account of Retrocessionaire and shall not affect the amount retained by
Retrocedant. The parties agree that as of the first anniversary of the date
hereof, Retrocessionaire shall pay to Retrocedant the difference, if any,
between the amount of EBUB as of the Effective Time and the aggregate amount
paid to and/or retained by Retrocedant prior to that date with respect to EBUB
as of the Effective Time. All amounts, if any, in respect of EBUB which are in
excess of EBUB as of the Effective Time, calculated pursuant to the first
sentence of this section 4.02(c), shall be for the account of Retrocessionaire
and no such amounts shall be retained by or payable to Retrocedant.

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     SECTION 4.03   DISPUTE RESOLUTION.

     (a)  After receipt of the Proposed Accounting, together with the work
papers used in preparation thereof, Retrocessionaire shall have 30 days (the
"REVIEW PERIOD") to review such Proposed Accounting. Unless Retrocessionaire
delivers written notice to Retrocedant on or prior to the 30th day of the Review
Period stating that it has material objections thereto, Retrocessionaire shall
be deemed to have accepted and agreed to the Proposed Accounting.
Retrocessionaire shall not object to any method, principle, practice or policy
employed in the preparation of the Proposed Accounting if such method,
principle, practice or policy is consistent in all material respects with that
employed in the preparation and presentation of Retrocedant's statutory annual
financial statement as of December 31, 2001 as filed with the Vermont Department
of Insurance and as submitted to The St. Paul. If Retrocessionaire so notifies
Retrocedant of its material objections to the Proposed Accounting, the parties
shall in good faith attempt to resolve, within 30 days (or such longer period as
the parties may agree) following such notice (the "RESOLUTION PERIOD"), their
differences with respect to such material objections and any resolution by them
as to any disputed amounts shall be final, binding and conclusive.

     (b)  Any amount remaining in dispute at the conclusion of the Resolution
Period ("UNRESOLVED CHANGES") shall be submitted to arbitration. One arbiter
(each arbiter, an "ARBITER") shall be chosen by Retrocedant, the other by
Retrocessionaire, and an umpire (the "UMPIRE") shall be chosen by the two
Arbiters before they enter upon arbitration. In the event that either party
should fail to choose an Arbiter within 30 days following a written request by
the other party to do so, the requesting party may choose two Arbiters, but only
after providing 10 days' written notice of its intention to do so and only if
such other party has failed to appoint an Arbiter within such 10 day period. The
two Arbiters shall in turn choose an Umpire who shall act as the umpire and
preside over the hearing. If the two Arbiters fail to agree upon the selection
of an Umpire within 30 days after notification of the appointment of the second
Arbiter, the selection of the Umpire shall be made by the American Arbitration
Association. All Arbiters and Umpires shall be active or retired disinterested
property/casualty actuaries of insurance or reinsurance companies or Lloyd's of
London Underwriters.

     (c)  Each party shall present its case to the Arbiters within 30 days
following the date of appointment of the Umpire, unless the parties mutually
agree to an extension of time. The decision of the Arbiters shall be final and
binding on both parties; but failing to agree, they shall call in the Umpire and
the decision of the majority shall be final and binding upon both parties.
Judgment upon the final decision of the Arbiters may be entered in any court of
competent jurisdiction.

     (d)  Each party shall bear the expense of its own Arbiter, and shall
jointly and equally bear with the other the expense of the Umpire and of the
arbitration unless otherwise directed by the Arbiters.

     (e)  Any arbitration proceedings shall take place in New York, New York
unless the parties agree otherwise.

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     (f)  Arbitration shall not be a condition precedent to any right of action
hereunder.

     (g)  Once the Proposed Accounting has been finalized in accordance with the
above process, the Final Section A Premium and the Final Section B Premium
amounts shall be as set forth in the Proposed Accounting, as determined by the
Arbiters, if applicable. In the event the sum of such amounts is greater than
the amount paid by Retrocedant to Retrocessionaire on the Effective Date,
Retrocedant shall promptly pay to the account of Retrocessionaire the difference
plus interest on such amount at the Applicable Rate from and including the
Effective Date to and including the date of such payment. In the event the
aggregate of such amounts is lower than the amount paid by Retrocedant to
Retrocessionaire on the Effective Date, Retrocessionaire shall promptly pay to
the account of Retrocedant the difference plus interest on such amount at the
Applicable Rate from the Effective Date to the date of such payment.

     SECTION 4.04   PROFIT/LOSS SETTLEMENT. Upon the commutation or final loss
settlement or termination of the Reinsurance Contract, Retrocessionaire and
Retrocedant shall share the profits, if any, on the following basis: 33 1/3% to
Retrocessionaire and 66 2/3% to Retrocedant.

     "Profits" shall mean the residual balance in the following specified
Mountain Ridge Sterling Account account (the "ACCOUNT"):

     Bank:                      Citibank - London
     Account Name:              Mountain Ridge Insurance Company
     Account No.:               10090360
     Sort Code:                 18-50-08
     Swift Code:                CITIGB2L
     Ref.:                      Funds from Chase New York for investment

     The Account shall be maintained by Retrocedant in a manner consistent with
its current practices, including, but not limited to the application of an
investment credit at the inception of each calendar year [to be specified].

     If the residual balance of the Account is negative and the Reinsurance
Contract is in a loss position, the aggregate loss shall be allocated according
to the experience of each of the three underlying underwriting years and the
Retrocedant shall be allocated losses arising from the 2000 and 2001
underwriting years and the Retrocessionaire shall be allocated losses arising
from the 2002 underwriting year.

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                                    ARTICLE V

                                CEDING COMMISSION

     With respect to the Reinsurance Contract, Retrocessionaire shall pay the
Retrocedant a ceding commission (the "CEDING COMMISSION") with respect to the
Section B (Prospective) Coverage Period, and such Ceding Commission shall equal
one hundred percent (100%) of the actual expenses incurred in writing the
Reinsurance Contract, including actual ceding commissions and brokerage paid, as
determined in accordance with Retrocedant's customary practices and procedures
and as submitted to The St. Paul, all as allocable pro rata to periods from and
after the Effective Time.

                                   ARTICLE VI

                               ORIGINAL CONDITIONS

     All retrocessions assumed under this Agreement shall be subject to the same
rates, terms, conditions, waivers and interpretations, and to the same
modifications and alterations, as the Reinsurance Contract.

                                   ARTICLE VII

                              INURING RETROCESSIONS

     SECTION 7.01   ALLOCATION TO RETROCESSIONAIRE. Retrocedant agrees that the
retrocession contracts purchased by St. Paul Re from third party
retrocessionaires ("THIRD PARTY Retrocessionaires") on behalf of Retrocedant
prior to the Effective Time that are listed on Exhibit B hereto shall inure to
the benefit of Retrocessionaire to the extent of liabilities covered under this
Agreement ("INURING RETROCESSIONS"), subject to the allocations in Exhibits C, D
and E.

     SECTION 7.02   TRANSFER. Retrocedant and Retrocessionaire shall use their
respective commercially reasonable efforts to obtain the consent of Third Party
Retrocessionaires under the Inuring Retrocessions to include Retrocessionaire as
a direct reinsured with respect to the Reinsurance Contract or, in the
alternative, to make all payments directly to Retrocessionaire, to the extent
allocable to the Reinsurance Contract, in the manner set forth in Exhibit C
hereto, and to seek all payments, to the extent allocable to the Reinsurance
Contract, in the manner set forth herein in Exhibit D hereto, directly from
Retrocessionaire, it being understood that Retrocessionaire shall bear all risk
of non-payment or non-collectibility under the Inuring Retrocessions.

     SECTION 7.03   INURING RETROCESSIONS CLAIMS.

     (a)  Each of the parties agrees to transfer to the other party all
recoveries or any portion thereof that such party receives on or after the
Effective Time pursuant to the Inuring Retrocessions which are allocated to the
other party, in the manner set forth in Exhibit C hereto. Retrocedant shall use
its commercially reasonable efforts to collect any recoveries due to
Retrocessionaire under the Inuring Retrocessions that indemnify the

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Retrocedant for losses or expenses payable or return of premium allocable to the
Retrocessionaire and shall transfer any such recoveries received to
Retrocessionaire. The parties agree that Retrocessionaire's obligations to make
payments pursuant to the Inuring Retrocessions or to reimburse Retrocedant
pursuant to this Agreement shall not be waived by non-receipt of any such
amounts. Retrocessionaire shall reimburse Retrocedant for one hundred percent
(100%) of any expenses reasonably incurred by Retrocedant in attempting to make
such collection, including all allocated expenses, as determined in accordance
with St. Paul Re's customary practices and procedures. Retrocessionaire shall
have the right to associate with Retrocedant, at Retrocessionaire's own expense,
in any actions brought by Retrocedant to make such collections.

     (b)  In the event claims of Retrocedant and Retrocessionaire aggregate in
excess of the applicable limit under an Inuring Retrocession, all limits
applicable to either Retrocedant or Retrocessionaire shall be allocated between
Retrocedant and Retrocessionaire in the manner set forth in Exhibit E hereto.

     SECTION 7.04   INITIAL CONSIDERATION. On the Effective Date,
Retrocessionaire shall reimburse Retrocedant for one hundred percent (100%) of
any and all unearned premiums paid by Retrocedant under such Inuring
Retrocessions net of any applicable unearned ceding commissions paid to
Retrocedant thereunder.

     SECTION 7.05   ADDITIONAL CONSIDERATION. Retrocessionaire agrees to pay
directly to Third Party Retrocessionaires under the Inuring Retrocessions all
future premiums Retrocedant is obligated to pay pursuant to the terms of the
Inuring Retrocessions to the extent that such premiums are allocable to
Retrocessionaire in the manner set forth in Exhibit D and to indemnify
Retrocedant for all such premiums paid directly by Retrocedant, net of any
ceding commissions and similar amounts paid by Third Party Retrocessionaires to
Retrocedant.

     SECTION 7.06   TERMINATION OR COMMUTATION OF INURING RETROCESSIONS.

     (a)  With respect to any Inuring Retrocessions providing coverage solely
with respect to the Reinsurance Agreement, Retrocedant agrees, on behalf of
itself and its affiliates, not to terminate or commute any such Inuring
Retrocession without the written consent of Retrocessionaire.

     (b)  With respect to any Inuring Retrocessions providing coverage for both
the Reinsurance Agreement and to business not being transferred, neither party
shall take any action or fail to take any action that would reasonably result in
the termination or commutation of any Inuring Retrocession, without the prior
written consent of the other party, such consent not to be unreasonably
withheld.

                                  ARTICLE VIII

                 LOSS AND LOSS EXPENSE; SALVAGE AND SUBROGATION
                               FOLLOW THE FORTUNES

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     (a)  Retrocessionaire shall be liable for one hundred percent (100%) of all
future loss, loss adjustment expenses, incurred but not reported losses and
other payment obligations that arise under the Reinsurance Contract on and after
January 1, 2002 and are payable as of or after the Effective Time and shall
reimburse Retrocedant for any losses, loss adjustment expenses and other payment
obligations paid by Retrocedant following the Effective Time in respect of the
Reinsurance Contract, net of any recoveries received by Retrocedant with respect
thereto, including recoveries under Inuring Retrocessions. Retrocessionaire
shall have the right to all salvage and subrogation on the account of claims and
settlements with respect to the Reinsurance Contract.

     (b)  In the event of a claim under the Reinsurance Contract, the
Retrocedant will assess the validity of the claim and make a determination as to
payment, consistent with the claims handling guidelines previously provided to
Retrocedant in writing by Retrocessionaire and Retrocessionaire may exercise its
rights under Section 10.01 in respect thereof. Retrocedant shall provide prompt
notice of any claim in excess of $500,000 to Retrocessionaire. All payments made
by Retrocedant, whether under strict contract terms or by way of compromise,
shall be binding on Retrocessionaire. In addition, if Retrocedant refuses to pay
a claim in full and a legal proceeding results, Retrocessionaire will be
unconditionally bound by any settlement agreed to by Retrocedant or the adverse
judgment of any court or arbitrator (which could include any judgment for bad
faith, punitive damages, excess policy limit losses or extra contractual
obligations) and Retrocedant may recover with respect to such settlements and
judgments under this Agreement. Though Retrocedant will settle such claims and
litigation in good faith, Retrocessionaire is bound to accept the settlements
paid by Retrocedant and such settlements may be for amounts that could be
greater than the amounts that would be agreed to by Retrocessionaire if
Retrocessionaire were to settle such claims or litigation directly. It is the
intent of this Agreement that Retrocessionaire shall in every case in which this
Agreement applies and in the proportions specified herein, "follow the fortunes"
of Retrocedant in respect of risks Retrocessionaire has accepted under this
Agreement.

                                   ARTICLE IX

                          EXTRA CONTRACTUAL OBLIGATIONS

          In the event Retrocedant or Retrocessionaire is held liable to pay any
punitive, exemplary, compensatory or consequential damages because of alleged or
actual bad faith or negligence related to the handling of any claim under any
Reinsurance Contract or otherwise in respect of such Reinsurance Contract, the
parties shall be liable for such damages in proportion to their responsibility
for the conduct giving rise to the damages. Such determination shall be made by
Retrocedant and Retrocessionaire, acting jointly and in good faith, and in the
event the parties are unable to reach agreement as to such determination,
recourse shall be had to Article XV hereof.

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                                    ARTICLE X

                     ADMINISTRATION OF REINSURANCE CONTRACT

     SECTION 10.01  ADMINISTRATION.

     (a)  The parties agree that, as of the Effective Time, Retrocedant shall
have the sole authority to administer the Reinsurance Contract in all respects,
which authority shall include, but not be limited to, authority to bill for and
collect premiums, adjust all claims and handle all disputes thereunder and to
effect any and all amendments, commutations and cancellations of the Reinsurance
Contract, subject, however, in the case of administration of claims, to all
claims handling guidelines provided in advance in writing by Retrocessionaire to
Retrocedant. Retrocedant shall not, on its own, settle any claim, waive any
right, defense, setoff or counterclaim relating to the Reinsurance Contract with
respect to amounts in excess of $500,000, and shall not amend, commute or
terminate any of the Reinsurance Contract without the prior written consent of
Retrocessionaire.

     (b)  Notwithstanding the foregoing, Retrocessionaire may, at its discretion
and at its own expense, assume the administration, defense, and settlement of
any claim upon prior written notice to Retrocedant. Upon receipt of such notice,
Retrocedant shall not compromise, discharge or settle such claim except with the
prior written consent of Retrocessionaire. Retrocessionaire shall not take any
action in the administration of such claim that would reasonably be expected to
adversely affect Retrocedant, its business or its reputation, without the prior
written consent of Retrocedant. Subject to the terms of Article IX hereof,
Retrocessionaire shall indemnify Retrocedant for all Losses, including punitive,
exemplary, compensatory or consequential damages arising from such assumption of
the conduct of such settlement pursuant to Article XIV herein.

     SECTION 10.02  The parties agree that, as of the Effective Time,
Retrocedant shall have the sole authority to administer the Reinsurance Contract
in all respects, which authority shall include, but not be limited to, authority
to bill for and collect premiums, adjust all claims and handle all disputes
thereunder and to effect any and all amendments, commutations and cancellations
of the Reinsurance Contract, subject, however, in the case of adjustment of
claims, to all claims handling guidelines provided in advance in writing by
Retrocessionaire to Retrocedant.

     SECTION 10.03  REPORTING AND REGULATORY MATTERS. Each party shall provide
the notices and filings required to be made by it to state regulatory
authorities as a result of this Agreement. Notwithstanding the foregoing, each
party shall provide to the other party any information in its possession
regarding the Reinsurance Contract as reasonably required by the other party to
make such filings and in a form as agreed to by the parties.

     SECTION 10.04  DUTY TO COOPERATE. Upon the terms and subject to the
conditions and other agreements set forth herein, each party agrees to use its
commercially reasonable efforts to take, or cause to be taken, all actions, and
to do, or

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cause to be done, and to assist and cooperate with the other party in doing, all
things necessary or advisable to perform the transactions contemplated by this
Agreement.

     SECTION 10.05  COMMUNICATIONS RELATING TO THE REINSURANCE CONTRACT.
Following the Effective Time, Retrocedant and Retrocessionaire shall each
promptly forward to the other copies of all material notices and other written
communications it receives relating to the Reinsurance Contract (including,
without limitation, all inquiries and complaints from state insurance
regulators, brokers and other service providers and reinsureds and all notices
of claims, suits and actions for which it receives service of process.)

                                   ARTICLE XI

                             REPORTS AND REMITTANCES

     SECTION 11.01  REPORT FROM RETROCEDANT. Within thirty days following the
end of each month, Retrocedant shall provide Retrocessionaire with a summary
statement of account for the previous month showing all activity relating to the
Reinsurance Contract, including related administration costs and expenses
incurred by Retrocedant in the form set forth hereto as Exhibit F. The monthly
statement of account shall also provide a breakdown of any amounts due to the
Retrocedant or Retrocessionaire, as the case may be, as reimbursement for paid
claims, premiums or other amounts due pursuant to the terms of this Agreement.

     SECTION 11.02  REMITTANCES. Within two Business Days after delivery of each
monthly report pursuant to Section 11.01, Retrocedant and Retrocessionaire shall
settle all amounts then due under this Agreement for that month.

     SECTION 11.03  LATE PAYMENTS. Should any payment due any party to this
Agreement be received by such party after the due date for such payment under
this Agreement, interest shall accrue from the date on which such payment was
due until payment is received by the party entitled thereto, at an annual rate
equal to the London Interbank Offered Rate quoted for six month periods as
reported in The Wall Street Journal on the first Business Day of the month in
which such payment first becomes due plus one hundred basis points (the
"APPLICABLE RATE").

     SECTION 11.04  COST REIMBURSEMENT. Retrocessionaire shall reimburse for its
allocated share of all costs and expenses incurred by Retrocedant in
administering the Reinsurance Contract as set forth in Exhibit I hereto.

                                   ARTICLE XII

                             MAINTENANCE OF LICENSES

     Each of Retrocedant and Retrocessionaire hereby covenants to maintain at
all times all licenses and authorizations required to undertake the actions
contemplated hereby.

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                                  ARTICLE XIII

                                ACCESS TO RECORDS

          From and after the Closing Date, Retrocedant shall afford to
Retrocessionaire and its respective authorized accountants, counsel and other
designated representatives (collectively, "REPRESENTATIVES") reasonable access
(including using commercially reasonable best efforts to give access to Persons
possessing information) during normal business hours to all data and information
that is specifically described in writing (collectively, "INFORMATION") within
the possession of Retrocedant relating to the liabilities transferred hereunder,
insofar as such information is reasonably required by Retrocessionaire.
Similarly, from and after the Closing Date, Retrocessionaire shall afford to
Retrocedant, any Post-closing Subsidiary of Retrocedant and their respective
Representatives reasonable access (including using commercially reasonable best
efforts to give access to Persons possessing information) during normal business
hours to Information within Retrocessionaire's possession relating to
Retrocedant, insofar as such information is reasonably required by Retrocedant.
Information may be requested under this Article XIII for, without limitation,
audit, accounting, claims, litigation (other than any claims or litigation
between the parties hereto) and tax purposes, as well as for purposes of
fulfilling disclosure and reporting obligations and for performing this
Agreement and the transactions contemplated hereby.

     From and after the Closing Date, Retrocessionaire and Retrocedant or their
designated representatives may inspect, at the place where such records are
located, any and all data and information that is specifically described in
writing within the possession of the other party hereto reasonably relating to
this Agreement, on reasonable prior notice and during normal business hours. The
rights of the parties under this Article XIII shall survive termination of this
Agreement and shall continue for as long as there may be liabilities under the
Reinsurance Contract or reporting or retention requirements under applicable
law. In addition, each party shall have the right to take copies (including
electronic copies) of any information held by the other party that reasonably
relates to this Agreement or the Reinsurance Contract. Each party shall, and
shall cause its designated representative to, treat and hold as confidential
information any information it receives or obtains pursuant to this
Article XIII.

                                   ARTICLE XIV

                                 INDEMNIFICATION

     SECTION 14.01  INDEMNIFICATION BY RETROCEDANT. Retrocedant agrees to
indemnify, defend and hold harmless Retrocessionaire, and its officers,
directors and employees with respect to any and all Losses arising from any
breach by Retrocedant of any representation, warranty or covenant herein.
Retrocedant further agrees to indemnify, defend and hold harmless
Retrocessionaire and its officers, directors and employees against any and all
Losses arising out of Retrocedant's administration of the Reinsurance Contracts,
including but not limited to extracontractual obligations, payments in excess of
policy limits and settlements made in respect of any such claims to

                                       12
<Page>

the extent arising from the gross negligence or willful misconduct of
Retrocedant except to the extent such actions are taken with the prior consent
or direction of Retrocessionaire. Such indemnification obligations shall be
limited to the aggregate of all fees paid to Retrocedant pursuant to Section
11.04 hereof.

     SECTION 14.02  INDEMNIFICATION BY RETROCESSIONAIRE. Retrocessionaire agrees
to indemnify, defend and hold harmless Retrocedant, and its officers, directors
and employees with respect to any and all Losses arising from any breach by
Retrocessionaire of any representation, warranty or covenant herein.
Retrocessionaire further agrees to indemnify, defend and hold harmless
Retrocedant and its officers, directors and employees against any and all Losses
arising out of Retrocessionaire's administration of the Reinsurance Contracts,
including but not limited to extracontractual obligations, payments in excess of
policy limits and settlements made in respect of any such claims.

     SECTION 14.03  INDEMNIFICATION PROCEDURES. (a) If a party seeking
indemnification pursuant to this Article XIV (each, an "INDEMNITEE") receives
notice or otherwise learns of the assertion by a Person (including, without
limitation, any governmental entity) who is not a party to this Agreement or an
Affiliate thereof, of any claim or of the commencement by any such Person of any
Action (a "THIRD PARTY CLAIM") with respect to which the party from whom
indemnification is sought (each, an "INDEMNIFYING PARTY") may be obligated to
provide indemnification pursuant to this Section 14.01 or 14.02, such Indemnitee
shall give such Indemnifying Party written notice thereof promptly after
becoming aware of such Third Party Claim; PROVIDED that the failure of any
Indemnitee to give notice as provided in this Section 14.03 shall not relieve
the Indemnifying Party of its obligations under this Article XIV, except to the
extent that such Indemnifying Party is prejudiced by such failure to give
notice. Such notice shall describe the Third Party Claim in as much detail as is
reasonably possible and, if ascertainable, shall indicate the amount (estimated
if necessary) of the Loss that has been or may be sustained by such Indemnitee.

     (b)  An Indemnifying Party may elect to defend or to seek to settle or
compromise, at such Indemnifying Party's own expense and by such Indemnifying
Party's own counsel, any Third Party Claim. Within [30] days of the receipt of
notice from an Indemnitee in accordance with Section 14.03(a) (or sooner, if the
nature of such Third Party Claim so requires), the Indemnifying Party shall
notify the Indemnitee of its election whether the Indemnifying Party will assume
responsibility for defending such Third Party Claim, which election shall
specify any reservations or exceptions. After notice from an Indemnifying Party
to an Indemnitee of its election to assume the defense of a Third Party Claim,
such Indemnifying Party shall not be liable to such Indemnitee under this
Article XIV for any legal or other expenses (except expenses approved in writing
in advance by the Indemnifying Party) subsequently incurred by such Indemnitee
in connection with the defense thereof; PROVIDED that, if the defendants in any
such claim include both the Indemnifying Party and one or more Indemnitees and
in any Indemnitee's reasonable judgment a conflict of interest between one or
more of such Indemnitees and such Indemnifying Party exists in respect of such
claim or if the Indemnifying Party shall have assumed responsibility for such
claim with reservations or

                                       13
<Page>

exceptions that would materially prejudice such Indemnitees, such Indemnitees
shall have the right to employ separate counsel to represent such Indemnitees
and in that event the reasonable fees and expenses of such separate counsel (but
not more than one separate counsel for all such Indemnitees reasonably
satisfactory to the Indemnifying Party) shall be paid by such Indemnifying
Party. If an Indemnifying Party elects not to assume responsibility for
defending a Third Party Claim, or fails to notify an Indemnitee of its election
as provided in this Article XIV, such Indemnitee may defend or (subject to the
remainder of this Article XIV) seek to compromise or settle such Third Party
Claim at the expense of the Indemnifying Party.

     (c)  Neither an Indemnifying Party nor an Indemnitee shall consent to entry
of any judgment or enter into any settlement of any Third Party Claim which does
not include as an unconditional term thereof the giving by the claimant or
plaintiff to such Indemnitee, in the case of a consent or settlement by an
Indemnifying Party, or the Indemnifying Party, in the case of a consent or
settlement by the Indemnitee, of a written release from all liability in respect
to such Third Party Claim.

     (d)  If an Indemnifying Party chooses to defend or to seek to compromise or
settle any Third Party Claim, the Indemnitee shall make available at reasonable
times to such Indemnifying Party any personnel or any books, records or other
documents within its control or which it otherwise has the ability to make
available that are necessary or appropriate for such defense, settlement or
compromise, and shall otherwise cooperate in a reasonable manner in the defense,
settlement or compromise of such Third Party Claim.

     (e)  Notwithstanding anything in this Article XIV to the contrary, neither
an Indemnifying Party nor an Indemnitee may settle or compromise any claim over
the objection of the other; PROVIDED that consent to settlement or compromise
shall not be unreasonably withheld or delayed. If an Indemnifying Party notifies
the Indemnitee in writing of such Indemnifying Party's desire to settle or
compromise a Third Party Claim on the basis set forth in such notice (provided
that such settlement or compromise includes as an unconditional term thereof the
giving by the claimant or plaintiff of a written release of the Indemnitee from
all liability in respect thereof) and the Indemnitee shall notify the
Indemnifying Party in writing that such Indemnitee declines to accept any such
settlement or compromise, such Indemnitee may continue to contest such Third
Party Claim, free of any participation by such Indemnifying Party, at such
Indemnitee's sole expense. In such event, the obligation of such Indemnifying
Party to such Indemnitee with respect to such Third Party Claim shall be equal
to (i) the costs and expenses of such Indemnitee prior to the date such
Indemnifying Party notifies such Indemnitee of the offer to settle or compromise
(to the extent such costs and expenses are otherwise indemnifiable hereunder)
PLUS (ii) the lesser of (A) the amount of any offer of settlement or compromise
which such Indemnitee declined to accept and (B) the actual out-of-pocket amount
such Indemnitee is obligated to pay subsequent to such date as a result of such
Indemnitee's continuing to pursue such Third Party Claim.

     (f)  In the event of payment by an Indemnifying Party to any Indemnitee in
connection with any Third Party Claim, such Indemnifying Party shall be
subrogated to and shall stand in the place of such Indemnitee as to any events
or circumstances in

                                       14
<Page>

respect of which such Indemnitee may have any right or claim relating to such
Third Party Claim against any claimant or plaintiff asserting such Third Party
Claim or against any other Person. Such Indemnitee shall cooperate with such
Indemnifying Party in a reasonable manner, and at the cost and expense of such
Indemnifying Party, in prosecuting any subrogated right or claim.

     (g)  Except with respect to claims relating to actual fraud, the
indemnification provisions set forth in this section are the sole and exclusive
remedy of the parties hereto for any and all claims for indemnification under
this Agreement.

     SECTION 14.04  SURVIVAL. This Article XIV shall survive termination of this
Agreement.

                                   ARTICLE XV

                                   ARBITRATION

     (a)  As a condition precedent to any right of Action under this Agreement,
any dispute or difference between the parties hereto relating to the formation,
interpretation, or performance of this Agreement, or any transaction under this
Agreement, whether arising before or after termination, shall be submitted for
decision to a panel of three arbitrators (the "PANEL") at the offices of
Judicial Arbitration and Mediation Services, Inc. in accordance with the
Streamlined Arbitration Rules and Procedures of Judicial Arbitration and
Mediation Services, Inc.

     (b)  The party demanding arbitration shall do so by written notice
complying with the terms of Section 20.06. The arbitration demand shall state
the issues to be resolved and shall name the arbitrator appointed by the
demanding party.

     (c)  Within 30 days of receipt of the demand for arbitration, the
responding party shall notify the demanding party of any additional issues to be
resolved in the arbitration and the name of the responding party's appointed
arbitrator. If the responding party refuses or neglects to appoint an arbitrator
within 30 days following receipt of the written arbitration demand, then the
demanding party may appoint the second arbitrator, but only after providing 10
days' written notice of its intention to do so, and only if such other party has
failed to appoint the second arbitrator within such 10 day period.

     (d)  The two arbitrators shall, before instituting the hearing, select an
impartial arbitrator who shall act as the umpire and preside over the hearing.
If the two arbitrators fail to agree on the selection of a third arbitrator
within 30 days after notification of the appointment of the second arbitrator,
the selection of the umpire shall be made by the American Arbitration
Association. Upon resignation or death of any member of the Panel, a replacement
will be appointed in the same fashion as the resigning or deceased member was
appointed. All arbitrators shall be active or former officers of
property/casualty insurance or reinsurance companies, or Lloyd's underwriters,
and shall be disinterested in the outcome of the arbitration.

                                       15
<Page>

     (e)  Within 30 days after notice of appointment of all arbitrators, the
Panel shall meet and determine timely periods for briefs, discovery procedures
and schedules for hearings. The Panel shall have the power to determine all
procedural rules for the holding of the arbitration, including but not limited
to the inspection of documents, examination of witnesses and any other matter
relating to the conduct of the arbitration. The Panel shall interpret this
Agreement as an honorable engagement and not as merely a legal obligation and
shall make its decision considering the custom and practice of the applicable
insurance and reinsurance business. The Panel shall be relieved of all judicial
formalities and may abstain from following the strict rules of law. The decision
of any two arbitrators shall be binding and final. The arbitrators shall render
their decision in writing within 60 days following the termination of the
hearing. Judgment upon the award may be entered in any court of competent
jurisdiction.

     (f)  Except as otherwise provided herein, all proceedings pursuant hereto
shall be governed by the laws of the State of Vermont without giving effect to
any choice or conflict of laws provision or rule (whether of the State of
Vermont or any other jurisdiction) that would cause the application of the laws
of any jurisdiction other than the State of Vermont.

     (g)  The parties agree that any disputes subject to arbitration pursuant to
this Article XV that may also be subject to arbitration proceedings between
respective Affiliates of the parties shall be consolidated with and subject to
arbitration pursuant to this Article XV. The parties further agree that all
issues that are limited to a specific foreign jurisdiction under an agreement
between the respective affiliates of the parties shall be determined by this
Panel pursuant to the consolidation, in reference to the governing law of the
applicable agreement.

     (h)  Each party shall bear the expense of its own arbitrator and shall
share equally with the other party the expense of the umpire and of the
arbitration.

     (i)  Arbitration hereunder shall take place in New York, New York unless
the parties agree otherwise.

     (j)  This Article XV shall survive termination of this Agreement.

                                   ARTICLE XVI

                                   INSOLVENCY

     (a)  In the event of the insolvency of Retrocedant, this reinsurance shall
be payable directly to Retrocedant, or to its liquidator, receiver, conservator
or statutory successor on the basis of the liability of Retrocedant without
diminution because of the insolvency of Retrocedant or because the liquidator,
receiver, conservator or statutory successor of Retrocedant has failed to pay
all or a portion of any claim.

     (b)  It is agreed, however, that the liquidator, receiver, conservator or
statutory successor of Retrocedant shall give written notice to Retrocessionaire
of the pendency of a claim against Retrocedant indicating the Reinsurance
Contract, which claim would

                                       16
<Page>

involve a possible liability on the part of Retrocessionaire within a reasonable
time after such claim is filed in the conservation or liquidation proceeding or
in the receivership, and that during the pendency of such claim,
Retrocessionaire may investigate such claim and interpose, at its own expense,
in the proceeding where such claim is to be adjudicated any defense or defenses
that it may deem available to Retrocedant or its liquidator, receiver,
conservator or statutory successor. The expense thus incurred by
Retrocessionaire shall be chargeable, subject to the approval of the court,
against Retrocedant as part of the expense of conservation or liquidation to the
extent of a pro rata share of the benefit which may accrue to Retrocedant solely
as a result of the defense undertaken by Retrocessionaire.

     (c)  As to all reinsurance made, ceded, renewed or otherwise becoming
effective under this Agreement, the reinsurance shall be payable as set forth
above by Retrocessionaire to Retrocedant or to its liquidator, receiver,
conservator or statutory successor, except (1) where the Reinsurance Contract
specifically provides another payee in the event of the insolvency of
Retrocedant, and (2) where Retrocessionaire, with the consent of the reinsured
or reinsureds under the Reinsurance Contract, has assumed such Reinsurance
Contract obligations of Retrocedant as direct obligations of Retrocessionaire to
the payees under such Reinsurance Contract and in substitution for the
obligations of the Retrocedant to such payees.

                                  ARTICLE XVII

                                     OFFSET

     Retrocedant and Retrocessionaire shall have the right to offset any balance
or amounts due form one party to the other under the terms of this Agreement.
The party asserting the right of offset may exercise such right at any time
whether the balances due are on account of premiums, losses or otherwise.

                                  ARTICLE XVIII

                              ERRORS AND OMISSIONS

     Any inadvertent delay, omission, error or failure shall not relieve either
party hereto from any liability which would attach hereunder if such delay,
omission, error or failure had not been made provided such delay, omission,
error or failure is rectified as soon as reasonably practicable upon discovery.

                                   ARTICLE XIX

                        CREDIT FOR REINSURANCE; SECURITY

     SECTION 19.01  CREDIT FOR REINSURANCE. Retrocessionaire shall take all
actions reasonably necessary, if any, to permit Retrocedant to obtain full
financial statement credit in all applicable U.S. jurisdictions for all
liabilities assumed by the Retrocessionaire pursuant to this Agreement,
including but not limited to loss and loss

                                       17
<Page>

adjustment expense reserves, unearned premium reserves, reserves for incurred
but not reported losses, allocated loss adjustment expenses and ceding
commissions, and to provide the security required for such purpose, in a form
reasonably acceptable to Retrocedant. Any reserves required by the foregoing in
no event shall be less than the amounts required under the law of the
jurisdiction having regulatory authority with respect to the establishment of
reserves relating to the relevant Reinsurance Contract. For purposes of this
Article XIX, such "actions reasonably necessary" may include, without
limitation, the furnishing of a letter of credit or the establishment of a
custodial or trust account, as permitted under applicable law, to secure the
payment of the amounts due the Retrocedant under this Agreement.

     SECTION 19.02  EXPENSES. All expenses of establishing and maintaining any
letter of credit or other security arrangement shall be paid by
Retrocessionaire.

     SECTION 19.03  SECURITY.

     (a)  Retrocessionaire shall establish and maintain a trust fund for the
benefit of Retrocedant as security for the obligations of Retrocessionaire under
this Agreement. The trust fund shall be in a form reasonably satisfactory to
Retrocedant and shall comply in all material respects with the requirements
under Maryland Insurance Law applicable to trust funds established for credit
for reinsurance purposes.

     (b)  At the Closing Date, Retrocessionaire shall deposit qualifying assets
into the trust account equal to all payments and proceeds received by
Retrocessionaire in respect of the Reinsurance Contracts, including but not
limited to assets related to transferred reserves, premium payments, reinsurance
recoverables and other payments. As of the end of each calendar quarter,
Retrocessionaire shall calculate the balance of the trust fund and the aggregate
loss, loss adjustment expense reserves, unearned premium reserves, ceding
commission and other reserves related to the Reinsurance Contracts as reported
in the statutory financial statements filed by Retrocessionaire with the
Maryland Insurance Commission for such quarter and shall provide such
calculation to Retrocedant within five days of the filing of such statutory
financial statements with the Maryland Insurance Commission. If the balance of
the trust fund is less than the aggregate of the related reserves,
Retrocessionaire promptly shall deposit sufficient qualifying assets to cause
the balance of the trust fund to equal at least one hundred percent of such
aggregate reserves. If the balance of the trust fund is greater than the
aggregate of the related reserves, Retrocessionaire may withdraw assets equal to
the amount of such excess.

     (c)  Upon receipt of the quarterly calculation from Retrocessionaire,
Retrocedant shall have the right to reasonably object to such calculation and to
offer a reasonable proposal for reserve amounts. If the parties in good faith
are not able to resolve the disagreement within [two weeks] of Retrocedant's
indication of disagreement, the parties shall mutually agree upon an independent
actuarial firm to determine an appropriate level of aggregate reserves with
respect to the Reinsurance Contracts, such level to be no more than the amount
proposed by Retrocedant and no less than the amount reported by
Retrocessionaire, and both parties agree to be bound by such determination.

                                       18
<Page>

     (d)  Retrocessionaire shall retain the investment discretion with respect
to the assets in the trust, provided, however, that all assets held in the trust
shall qualify as admitted assets under Maryland Insurance Law.

     (e)  Retrocessionaire shall be permitted to liquidate the trust at the
earlier of (i) such time as Retrocessionaire's obligations under this Agreement
have been met or are terminated or waived or (ii) the reserves so reported by
Retrocessionaire do not exceed $100 million as of two successive calendar year
ends.

     (f)  Retrocedant shall bear the costs and expenses of the trustee relating
to the trust.

                                   ARTICLE XX

                            MISCELLANEOUS PROVISIONS

     SECTION 20.01  SEVERABILITY. If any term or provision of this Agreement
shall be held void, illegal, or unenforceable, the validity of the remaining
portions or provisions shall not be affected thereby.

     SECTION 20.02  SUCCESSORS AND ASSIGNS. This Agreement may not be assigned
by either party without the prior written consent of the other. The provisions
of this Agreement shall be binding upon and inure to the benefit of and be
enforceable by the parties hereto and their respective successors and assigns as
permitted herein.

     SECTION 20.03  NO THIRD PARTY BENEFICIARIES. Except as otherwise
specifically provided for in Article XIV of this Agreement, nothing in this
Agreement is intended or shall be construed to give any Person, other than the
parties hereto, their successors and permitted assigns, any legal or equitable
right, remedy or claim under or in respect of this Agreement or any provision
contained herein, and Retrocessionaire shall not be directly liable hereunder to
any reinsured under the Reinsurance Contract.

     SECTION 20.04  EQUITABLE RELIEF. Each party hereto acknowledges that if it
or its employees or agents violate the terms of this Agreement, the other party
will not have an adequate remedy at law. In the event of such a violation, the
other party shall have the right, in addition to any other rights that may be
available to it, to obtain in any court of competent jurisdiction injunctive
relief to restrain any such violation and to compel specific performance of the
provisions of this Agreement. The seeking or obtaining of such injunctive relief
shall not foreclose or limit in any way relief against either party hereto for
any monetary damage arising out of such violation.

     SECTION 20.05  EXECUTION IN COUNTERPARTS. This Agreement may be executed by
the parties hereto in any number of counterparts and by each of the parties
hereto in separate counterparts, each of which counterparts, when so executed
and delivered, shall be deemed to be an original, but all such counterparts
shall together constitute but one and the same instrument.

                                       19
<Page>

     SECTION 20.06  NOTICES. All notices, requests, claims, demands and other
communications hereunder shall be in writing and shall be deemed to have been
duly given if delivered by hand (with receipt confirmed), or by facsimile (with
transmission confirmed), or by certified mail, postage prepaid and return
receipt requested, addressed as follows (or to such other address as a party may
designate by written notice to the others) and shall be deemed given on the date
on which such notice is received:

     If to Retrocedant:

     Mountain Ridge Insurance Company
     [ADDRESS]

     If to Retrocessionaire:

     Platinum Underwriters Reinsurance Inc.
     Clarendon House, 2 Church Street
     Hamilton, Bermuda HM11
     Facsimile:  [ NO.   ]
     Attention:  Secretary

     SECTION 20.07  WIRE TRANSFER. All settlements in accordance with this
Agreement shall be made by wire transfer of immediately available funds on the
due date, or if such day is not a Business Day, on the next day which is a
Business Day, pursuant to the following wire transfer instructions: [ ]. Payment
may be made by check payable in immediately available funds in the event the
party entitled to receive payment has failed to provide wire transfer
instructions.

     SECTION 20.08  HEADINGS. Headings used herein are not a part of this
Agreement and shall not affect the terms hereof.

     SECTION 20.09  FURTHER ASSURANCES. Each of the parties shall from time to
time, on being reasonably requested to do so by the other party to this
Agreement, do such acts and/or execute such documents in a form reasonably
satisfactory to the party concerned as may be necessary to give full effect to
this Agreement and securing to that party the full benefit of the rights, powers
and remedies conferred upon it by this Agreement.

     SECTION 20.10  AMENDMENTS; ENTIRE AGREEMENT. This Agreement may be amended
only by written agreement of the parties. This Agreement, together with the
Formation and Separation Agreement, supersedes all prior discussions and written
and oral agreements and constitutes the sole and entire agreement between the
parties with respect to the subject matter hereof.

     SECTION 20.11  GOVERNING LAW. This Agreement shall be governed by the laws
of the State of Vermont, without giving effect to principles of conflicts of
laws thereof.

                                       20
<Page>

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be executed
by their duly authorized representatives as of the date first above written.


                                                 MOUNTAIN RIDGE INSURANCE
                                                 COMPANY

                                                 By
                                                   -----------------------------
                                                   Name:
                                                   Title:


                                                 PLATINUM UNDERWRITERS
                                                 REINSURANCE INC.

                                                 By
                                                   -----------------------------
                                                   Name:
                                                   Title:

                                       21
<Page>

                                    EXHIBIT A

                           ADJUSTMENT OF LOSS RESERVES

Reserves to be transferred to Retrocessionaire shall include loss and loss
adjustment expense reserves, including incurred but not reported loss and loss
adjustment expense reserves, and ceding commission reserves as of the Effective
Time with respect to the Reinsurance Contract net of retrocessional recoverables
under the Inuring Retrocession. "Ceding commission reserves" shall equal
reserves for estimated contingent commissions, profit commissions and
sliding-scale commissions.

                                       A-1
<Page>

                                    EXHIBIT B

                              INURING RETROCESSIONS

                          [To be provided by Platinum]

                                       B-1
<Page>

                                    EXHIBIT C

                            ALLOCATION OF RECOVERIES

1.   Recoveries available under an Inuring Retrocession shall be allocated
between the parties in proportion to the losses otherwise recoverable.

2.   Any and all loss recoveries and premium adjustments resulting from
triggering the 2002 Holborn cover will be allocated between St. Paul Companies
and Platinum Re based on variance from plan and in accordance with the existing
methodology shown below.

Variance from plan at an underwriting year level will be the basis for the
allocation. The 2000, 2001 and 2002 underwriting year plan loss ratios
associated with the 2002 calendar year plan loss ratio will be compared to
indicated ultimate loss ratios for the same underwriting years. These indicated
ultimate loss ratios are the same ones used to determine if the Holborn cover
has been triggered. The 2002 underwriting year must be segmented into three
pieces. Namely, that business written on Fire and Marine paper and subject to
transfer, that written on Fire and Marine paper and not subject to transfer and
that written on Platinum Re paper. The distinction is warranted as the cession
to Platinum Re will be net of the Holborn cover. The variance in loss ratio by
underwriting year will be multiplied by the respective underwriting year's EP
component in the 2002 calendar year. This is the same EP by underwriting year
that was used to calculate the total 2002 Holborn Year's EP. This dollar
variance will be the basis for determining the distribution to be applied to the
total loss recovery and AP. It is in this manner that the total loss recovery
and AP attributable to the 2002 Holborn Year will be allocated to underwriting
year. To the extent that the recoveries and AP's have been allocated to the 2000
and 2001 underwriting year's they will be afforded to St. Paul Companies.
Similarly, the allocation to that part of the 2002 underwriting year pertaining
to non-transferred business will also be realized by St. Paul Companies. The
allocation pertaining to business written on St Paul paper and transferred will
be used in determining the net transferred business that will be ceded to
Platinum Re. The remaining allocation associated with 2002 underwriting year
business written on Platinum Re paper will inure to the benefit of Platinum Re
directly. The margin for the 2002 Holborn cover will be distributed based on
earned premium and allocated between St Paul Companies and Platinum Re by
underwriting year.

                                       C-1
<Page>

                                    EXHIBIT D

                      ALLOCATION OF RETROCESSIONAL PREMIUMS

1.   Ceded premium will be allocated to cedant and underwriting year in
proportion to the earned subject premium. Ceding commission will be allocated in
the same manner.

2.   Any and all loss recoveries and premium adjustments resulting from
triggering the 2002 Holborn cover will be allocated between St. Paul Companies
and Platinum Re based on variance from plan and in accordance with the existing
methodology shown below.

Variance from plan at an underwriting year level will be the basis for the
allocation. The 2000, 2001 and 2002 underwriting year plan loss ratios
associated with the 2002 calendar year plan loss ratio will be compared to
indicated ultimate loss ratios for the same underwriting years. These indicated
ultimate loss ratios are the same ones used to determine if the Holborn cover
has been triggered. The 2002 underwriting year must be segmented into three
pieces. Namely, that business written on Fire and Marine paper and subject to
transfer, that written on Fire and Marine paper and not subject to transfer and
that written on Platinum Re paper. The distinction is warranted as the cession
to Platinum Re will be net of the Holborn cover. The variance in loss ratio by
underwriting year will be multiplied by the respective underwriting year's EP
component in the 2002 calendar year. This is the same EP by underwriting year
that was used to calculate the total 2002 Holborn Year's EP. This dollar
variance will be the basis for determining the distribution to be applied to the
total loss recovery and AP. It is in this manner that the total loss recovery
and AP attributable to the 2002 Holborn Year will be allocated to underwriting
year. To the extent that the recoveries and AP's have been allocated to the 2000
and 2001 underwriting year's they will be afforded to St. Paul Companies.
Similarly, the allocation to that part of the 2002 underwriting year pertaining
to non-transferred business will also be realized by St. Paul Companies. The
allocation pertaining to business written on St Paul paper and transferred will
be used in determining the net transferred business that will be ceded to
Platinum Re. The remaining allocation associated with 2002 underwriting year
business written on Platinum Re paper will inure to the benefit of Platinum Re
directly. The margin for the 2002 Holborn cover will be distributed based on
earned premium and allocated between St Paul Companies and Platinum Re by
underwriting year.

3.   The $10 million of premium payable for 2002 under the Workers Compensation
$50 million excess of $75 million Payback Retrocession Contract will be split
$1 million for Platinum and $9 million for St. Paul. Such contract has a feature
that states that for certain unfavorable experience on the Whole Account Stop
Loss Cover the premium on this cover could reduce by as much as $9 million. In
this event the reduction in ceded premium would benefit the St. Paul
exclusively. The Platinum share would remain at $1 million.

     The contract has a feature that allows the Retrocessionaire to renew the
cover if it is in a loss position. In this event the subsequent years' premium
will be split in proportion to the losses incurred to the cover.

                                       D-1
<Page>

                                    EXHIBIT E

                              ALLOCATION OF LIMITS

     Available limits under an Inuring Retrocession shall be allocated between
the parties in proportion to the losses otherwise recoverable.

                                       E-1
<Page>

                                    EXHIBIT F

                          FORM OF RETROCEDANT'S REPORT

[TBD]

                                       F-1
<Page>

                                    EXHIBIT G

                      ALLOCATION OF ADMINISTRATIVE EXPENSES

Retrocessionaire shall pay to Retrocedant the "actual cost" to Retrocedant
(which shall consist of Retrocedant's direct and reasonable indirect costs), as
certified in good faith by Retrocedant. For greater certainty, the parties agree
that "actual cost" will include any incremental and out-of-pocket costs incurred
by Retrocedant in connection with the administrative services provided
hereunder, including the conversion, acquisition and disposition cost of
software and equipment acquired for the purposes of providing the services and
the cost of establishing requisite systems and data feeds and hiring necessary
personnel.

No later than 30 days following the last day of each calendar quarter,
Retrocedant shall provide Retrocessionaire with a report setting forth an
itemized list of the services provided to Retrocessionaire during such last
calendar quarter, in a form agreed to by the parties. Retrocessionaire shall
promptly (and in no event later than 30 days after receipt of such report,
unless Retrocessionaire is contesting the amount set forth in the report in good
faith) pay to Retrocedant by wire transfer of immediately available funds all
amounts payable as set forth in such report. Each party will pay all taxes for
which it is the primary obligor as a result of the provision of any service
under this Agreement; PROVIDED, that Retrocessionaire shall be solely
responsible for, and shall reimburse Retrocedent in respect of, any sales, gross
receipts or transfer tax payable with respect to the provision of any service
under this Agreement, and any such reimbursement obligation shall be in addition
to Retrocessionaire's obligation to pay for such service.

                                       G-1