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                                                                   EXHIBIT 10.20

                                                                  EXECUTION COPY

                            CAPITAL SUPPORT AGREEMENT

                  THIS CAPITAL SUPPORT AGREEMENT (this "Agreement"), dated as
of November 26, 2002, between Platinum Underwriters Holdings, Ltd., a holding
company organized under the laws of Bermuda ("Platinum Holdings"), and Platinum
Underwriters Reinsurance, Inc., an insurance company organized under the laws of
Maryland ("Platinum U.S."), a wholly owned indirect subsidiary of Platinum
Holdings.

                                   ARTICLE I

                         PLATINUM HOLDINGS OBLIGATIONS

         SECTION 1.01 Obligation to Provide Capital. Platinum Holdings will from
time to time make capital contributions to Platinum U.S. in such amounts as
shall be necessary to assure that Platinum U.S.'s surplus as regards
policyholders, as reported on its annual statement blank to be submitted to the
Maryland Insurance Department, will not be less than the company action level
rbc, as such term is defined in the Maryland Insurance Code.

         SECTION 1.02 Unconditional Obligations. The obligations of Platinum
Holdings to make capital contributions as provided herein shall be absolute and
unconditional under any and all circumstances and shall not be to any extent or
in any way discharged, impaired or otherwise affected except by performance
thereof in full accordance with the terms hereof. Without limiting the
generality of the foregoing, such obligations shall not be affected by any
insolvency, bankruptcy, liquidation, reorganization, adjustment, composition,
dissolution or winding up or other proceeding involving Platinum U.S. or
Platinum Holdings.

                                   ARTICLE II

             NO RIGHTS OF REINSUREDS; NO THIRD PARTY BENEFICIARIES

         This Agreement grants no rights to any person who obtains or is
otherwise covered by a reinsurance contract issued by Platinum U.S.
("Reinsureds") or any other creditor of Platinum U.S. and does not create any
third party beneficiaries. In the event of Platinum Holdings' failure to meet
its obligations under Article 1 hereof, only Platinum U.S. may enforce its
rights under Article I of this Agreement, and, if Platinum U.S. fails or refuses
to take timely action to enforce its rights under Article 1 of this Agreement,
no other party may proceed on its behalf directly against Platinum Holdings to
enforce Platinum U.S.'s rights under this Agreement.

                                  ARTICLE III

                          NO WAIVER; CUMULATIVE RIGHTS

         No failure on the part of Platinum U.S. to exercise, and no delay in
exercising, any right, remedy or power hereunder shall operate as a waiver
thereof, nor shall any single or partial exercise by Platinum U.S. of any right,
remedy or power hereunder preclude any other or future exercise of any other
right, remedy or power. Each and every right, remedy and power hereby

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granted to Platinum U.S. or allowed by law or other agreement shall be
cumulative and not exclusive of any other, and may be exercised by Platinum U.S.
from time to time.

                                   ARTICLE IV

                             AMENDMENTS; TERMINATION

         (a)      Except as provided in Section 4(b) hereof, this Agreement may
be terminated, amended or waived only in writing signed by the parties. Platinum
Holdings' obligations hereunder shall not survive any termination of this
Agreement under this Section 4(a).

         (b)      The obligations of Platinum Holdings under this Agreement
shall terminate and be of no further force or effect and shall not thereafter be
enforceable by Platinum U.S. or any other person or entity with respect to
Platinum U.S. after the sale by Platinum Holdings of a majority of the
outstanding voting capital stock of Platinum U.S. to any person or entity.

                                    ARTICLE V

                              SPECIFIC ENFORCEMENT

         Platinum Holdings acknowledges and agrees that Platinum U.S. may suffer
irreparable damage in the event that any of the provisions of this Agreement are
not performed in accordance with their specific terms or are otherwise breached.
Platinum Holdings accordingly agrees that Platinum U.S. shall be entitled to
specific performance and injunction to prevent or cure breaches of the
provisions of this Agreement, this being in addition to any other remedy to
which it may be entitled by law or equity.

                                   ARTICLE VI

                                 MISCELLANEOUS

         SECTION 6.01 Successors and Assigns. This Agreement shall be binding
upon and shall inure to the benefit of the parties hereto and their respective
successors and assigns.

         SECTION 6.02 Severability. In case any provision in this Agreement
shall be invalid, illegal or unenforceable, the validity, legality and
enforceability of the remaining provisions shall not in any way be affected or
impaired thereby.

         SECTION 6.03 Jurisdiction. Platinum Holdings hereby irrevocably agrees
that any action arising out of or relating to this Agreement may be instituted
in any state or federal court in the state of Maryland, submits to the
non-exclusive jurisdiction of any such court with respect to any such action,
and waives any objection which it may now or hereafter have to the laying of the
venue of any such action in any such court and any claim that any such action
brought in any such court has been brought in an inconvenient forum.
Notwithstanding the foregoing, nothing herein shall in any way affect the right
of Platinum U.S. to bring any action arising out of or relating to this
Agreement in any competent court elsewhere having jurisdiction over Platinum
Holdings or its property. Platinum Holdings hereby agrees that service of any
process, summons, notice or document by registered mail addressed to Platinum
Holdings at Clarendon

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House, 2 Church Street, Hamilton HM 11, Bermuda, shall be effective service of
process for any action, suit or proceeding brought against it in any court.

         SECTION 6.04 New York Law. This Agreement shall be governed by and
construed in accordance with the laws of the State of New York.

         SECTION 6.05 Counterparts; Headings. This Agreement may be executed in
any number of counterparts, each of which shall be an original, but such
counterparts shall together constitute but one and the same instrument The
headings are inserted for convenience only and are not to be construed as part
of this Agreement.

         SECTION 6.06 Duration. Except as provided in Article IV, this Agreement
shall continue until the third anniversary of the date hereof after which it
shall have no force or effect.

         SECTION 6.07 Representations and Warranties. Each party hereto
represents and warrants that this Agreement has been duly authorized, executed
and delivered by such party and that this Agreement constitutes a valid and
legally binding obligation of such party enforceable in accordance with its
terms, subject, as to enforcement, to bankruptcy, insolvency, reorganization and
after laws of general applicability relating to or affecting creditor's rights
and to general equity principles.

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                  IN WITNESS WHEREOF, Platinum Holdings and Platinum U.S. have
caused this Agreement to be duly executed as of the date first above written.

                                           PLATINUM UNDERWRITERS HOLDINGS, LTD.

                                           By:/s/ JEROME T. FADDEN
                                              ----------------------------------
                                              Name:  JEROME T. FADDEN
                                              Title: CHIEF EXECUTIVE OFFICER

                                           PLATINUM UNDERWRITERS REINSURANCE
                                              INC.

                                           By:/s/ MICHAEL D. PRICE
                                              ----------------------------------
                                              Name:  MICHAEL D. PRICE
                                              Title: PRESIDENT

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