<Page>

                                                                    Exhibit 10.6


                        FORM OF MASTER SERVICES AGREEMENT

                  This Agreement, dated as of __________, 2002, is entered into
by and between The St. Paul Companies, Inc., a Minnesota corporation ("ST.
PAUL"), and Platinum Underwriters Holdings, Ltd., a Bermuda company
("PLATINUM").

                  WHEREAS, the parties have entered into a Formation and
Separation Agreement (the "FORMATION AND SEPARATION AGREEMENT"), in which they
have set forth certain terms governing St. Paul's sponsorship of the
organization of Platinum and its subsidiaries, actions to be taken in respect of
Platinum's initial public offering (the "PUBLIC OFFERING"), of its common
shares, par value $0.01 per share, and the ongoing relationships between St.
Paul and its subsidiaries and Platinum and its subsidiaries following the
consummation of the Public Offering;

                  WHEREAS, as contemplated by the Formation and Separation
Agreement, St. Paul and Platinum and certain of their Post-closing Subsidiaries
are entering into several quota share retrocession agreements (the "QUOTA SHARE
RETROCESSION AGREEMENTS"), in which St. Paul is agreeing to retrocede, or cause
certain of its Post- closing Subsidiaries to retrocede, to certain of Platinum's
Post-closing Subsidiaries, and certain of Platinum's Post-closing Subsidiaries
will agree to reinsure, certain of the reinsurance contracts entered into by St.
Paul or certain of its Subsidiaries (the "REINSURANCE AGREEMENTS"), in each case
as specified in the Quota Share Retrocession Agreements;

                  WHEREAS, as contemplated by the Formation and Separation
Agreement, St. Paul intends to provide, or cause one or more of its Post-closing
Subsidiaries to provide, contingent upon the consummation of the Public
Offering, certain administrative, accounting, human resources, systems and other
support services (together, the "SERVICES") to Platinum or certain of its
Post-closing Subsidiaries, for a specified transition period after the Closing
Date;
                  NOW, THEREFORE, in furtherance of the transactions
contemplated by the Formation and Separation Agreement and in consideration of
the promises and the mutual covenants and agreements contained therein and
herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereby agree as
follows:

<Page>

                  1.       SERVICES TO BE PROVIDED.

                  (a)      SERVICES. St. Paul hereby agrees to provide, or cause
its Post-closing Subsidiaries to provide, to Platinum or its Post-closing
Subsidiaries, from and after the Closing Date each of the services (the
"SERVICES") specified on Schedules A through ___ hereto (as such may be revised
from time to time pursuant to Section 1(f)).

                  (b)      STANDARD FOR SERVICES. St. Paul shall provide each of
the Services in such manner as Platinum may reasonably request from time to time
for purposes of this Agreement; PROVIDED, that St. Paul shall not be required to
provide, or cause to be provided, the Services at a standard materially higher
than the standard generally provided by St. Paul in respect of other business of
St. Paul. St. Paul shall maintain all licenses and authorizations required for
it to provide the Services pursuant to this Agreement.

                  (c)      PERIOD OF SERVICES. St. Paul shall provide each
Service until March 31, 2003 or such shorter period as may be specified in the
applicable Service schedule attached hereto (each such period, the "MAXIMUM
SERVICE PERIOD" for such Service), PROVIDED that, for each Service, St. Paul
shall in good faith consider requests by Platinum to extend the time period for
provision of the Service beyond the Maximum Service Period in light of the
circumstances at the time of such request. St. Paul and Platinum shall agree
upon the terms that will govern the provision of the particular Service to be so
provided at the time that Platinum makes such request.

                  (d)      PRICE OF SERVICES. With respect to the provision of
each Service, Platinum shall pay to St. Paul or the St. Paul Subsidiary
designated by St. Paul the "actual cost" to St. Paul or its Subsidiary (which
shall consist of St. Paul's or such Subsidiary's direct and reasonable indirect
costs), as the case may be, as certified in good faith by St. Paul. For greater
certainty, the parties agree that "actual cost" will include any incremental and
out-of-pocket costs incurred by St. Paul in connection with the Services,
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.

                  (e)      TRANSITION ASSISTANCE.

                           (i)      EXIT STRATEGY. Platinum shall use
                           commercially reasonable efforts in order to terminate
                           the need for the Services as soon as reasonably
                           practicable following the Closing Date (the
                           "TRANSITION"), and in order to accomplish this
                           Transition, Platinum will need assistance from the
                           employees, contractors or managed vendors of St.
                           Paul. St. Paul agrees to assign its Transition
                           coordinator (as set forth in paragraph (ii) below)
                           and to provide other reasonably necessary assistance
                           to allow Platinum and its Post-closing Subsidiaries
                           to exit St. Paul's systems in a timely and efficient
                           manner.

                           (ii)     SERVICE COORDINATORS. Platinum and St. Paul
                           shall each


                                      -2-
<Page>

                           designate one Service coordinator having skills and
                           experience reasonably acceptable to the other party
                           who will provide continuous oversight and
                           coordination of, and communicate concerning disputes
                           with respect to, the Services, who will be available
                           to Platinum and St. Paul during normal business hours
                           and who will be responsible for providing for or
                           delegating the provision of assistance regarding the
                           Services. The Service coordinators will cooperate on
                           a regular basis to plan for the delivery of Services,
                           including the timetable for the provision of such
                           Services and the incurring of related costs. Platinum
                           and St. Paul may from time to time substitute the
                           persons serving as Service Coordinators with other
                           persons qualified to serve in those positions.

                           (iii)    DOCUMENTATION. Subject to any
                           confidentiality or other obligations to third
                           parties, St. Paul will provide to Platinum all
                           service operating manuals and other written materials
                           relating to the Services, and any supplements or
                           updates to such manuals and materials, as reasonably
                           requested by Platinum; subject to Section 4, the
                           materials provided pursuant to this clause may be
                           copied by Platinum at its own expense.

                  (f)      REVISIONS TO SERVICES. This Agreement and the
Schedules hereto are intended to describe all of the Services that Platinum and
St. Paul have determined to be necessary and advisable as of the date hereof,
but the parties anticipate that the complexity of the transactions contemplated
by this Agreement will result in incomplete Schedules. Platinum shall promptly
notify St. Paul in writing if it becomes aware of Services different from or in
addition to those listed on the Schedules hereto that are necessary and
advisable, and the parties will cooperate in good faith to promptly agree to
revisions of the Schedules as necessary and advisable to reflect the intention
of the parties as to the provision of Services and the payment therefor.

                  (g)      COOPERATION. Upon the terms and subject to the
conditions and other agreements set forth herein, each party agrees to use
commercially reasonable efforts to take, or cause to be taken, all actions, and
to do, or 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.

                  2.       TERM AND TERMINATION.

                  (a)      This Agreement shall be construed as a separate and
independent agreement for each Service provided hereunder, PROVIDED that this
Agreement shall expire on March 31, 2003, subject to the provisions of Section
1(c). Any specific Service may be subject to termination at the election of
Platinum upon 30 days prior written notice at any time prior to the Maximum
Service Period for such Service, as indicated on the applicable Schedule. Any
termination of this Agreement with respect to any Service shall


                                      -3-
<Page>

not terminate the Agreement with respect to any other Service then being
provided subject to this Agreement. Notwithstanding anything in this Agreement
to the contrary, any termination of this Agreement with respect to any Service
shall be final.

                  (b)      Unless earlier terminated, this Agreement will expire
with respect to each Service provided hereunder at the end of the Maximum
Service Period for such Service.

                  3.       BILLING; TAXES. No later than 30 days following the
last day of each calendar quarter, St. Paul shall provide Platinum with a report
setting forth an itemized list of the Services provided to Platinum during such
last calendar quarter, in a form agreed to by the parties. Platinum shall
promptly (and in no event later than 30 days after receipt of such report,
unless Platinum is contesting the amount set forth in the report in good faith)
pay to St. Paul by wire transfer of immediately available funds all amounts
payable as set forth in such report. Platinum shall be solely responsible for,
and shall reimburse and indemnify St. Paul and hold it harmless on an after-tax
basis, for any taxes payable with respect to or by reason of the provision of
any Service under this Agreement, other than net income taxes imposed upon St.
Paul with respect to amounts payable under Section 1(d) of this Agreement, and
such reimbursement and indemnity obligation shall be in addition to Platinum's
obligation to pay for such Service.

                  4.       RELATIONSHIPS AMONG THE PARTIES, RECIPIENTS AND
PROVIDERS. Nothing in this Agreement shall cause the relationship between St.
Paul and Platinum to be deemed to constitute an agency, partnership or joint
venture. The terms of this Agreement are not intended to constitute any of the
parties and their Affiliates a joint employer for any purpose. Each of the
parties agrees that the provisions of this Agreement as a whole are not intended
to, and do not, constitute control of the other party (or any Affiliates
thereof) or provide it with the ability to control such other party (or any
Affiliates thereof), and each party hereto expressly disclaims any right or
power under this Agreement to exercise any power whatsoever over the management
or policies of the other (or any Affiliates thereof). Nothing in this Agreement
shall oblige either party hereto to act in breach of the requirements of any
law, rule or regulation applicable to it, including securities and insurance
laws, written policy statements of securities commissions, insurance and other
regulatory authorities, and the by-laws, rules, regulations and written policy
statements of relevant securities and self-regulatory organizations.

                  5.       REQUIREMENTS. Nothing in this Agreement requires
Platinum or any of its Post-closing Subsidiaries to purchase any particular
quantity or level of any Service provided under this Agreement.

                  6.       REGULATORY MATTERS. St. Paul will cooperate, and will
cause any of its Post-closing Subsidiaries providing Services hereunder to
cooperate, with each of Platinum and its Post-closing Subsidiaries and any
regulatory authorities to satisfy any regulatory requirements applicable to
entities that provide services to Platinum or its Post-closing Subsidiaries.

                  7.       GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY,
AND


                                      -4-
<Page>

CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK, WITHOUT REGARD
TO ITS CONFLICT OF LAWS PRINCIPLES.

                  8.       DISPUTE RESOLUTION.

                  (a)      MANDATORY ARBITRATION. The parties hereto shall
promptly submit any dispute, claim, or controversy arising out of or relating to
this Agreement and/or the provision of Services hereunder, including effect,
validity, breach, interpretation, performance, or enforcement (collectively, a
"DISPUTE") to binding arbitration in New York, New York at the offices of
Judicial Arbitration and Mediation Services, Inc. ("JAMS") before an arbitrator
(the "ARBITRATOR") in accordance with JAMS' Comprehensive Arbitration Rules and
Procedures and the Federal Arbitration Act, 9 U.S.C. Sections 1 ET SEQ. The
Arbitrator shall be a former judge selected from JAMS' pool of neutrals. The
parties agree that, except as otherwise provided herein respecting temporary or
preliminary injunctive relief, binding arbitration shall be the sole means of
resolving any Dispute. Judgment on any award of the Arbitrators may be entered
by any court of competent jurisdiction.

                  (b)      COSTS. The costs of the arbitration proceeding and
any proceeding in court to confirm or to vacate any arbitration award or to
obtain temporary or preliminary injunctive relief as provided in paragraph (c)
below, as applicable (including, without limitation, actual attorneys' fees and
costs), shall be borne by the unsuccessful party and shall be awarded as part of
the Arbitrator's decision, unless the Arbitrator shall otherwise allocate such
costs in such decision.

                  (c)      INJUNCTIVE RELIEF. The parties hereto may seek or
obtain temporary or preliminary injunctive relief in a court for any breach or
threatened breach of any provision hereof pending the hearing before and
determination of the Arbitrator. St. Paul hereby agrees that it shall continue
to provide, or cause its Affiliates to provide, any and all Services pending the
hearing before and determination of the Arbitrator, it being agreed and
understood that the failure to so provide may cause irreparable harm to Platinum
and its Affiliates and that the putative breaching party has assumed all of the
commercial risks associated with such breach or threatened breach of any
provision hereof by such party.

                  (d)      COURTS. The parties agree that the State and Federal
courts in The City of New York shall have jurisdiction for purposes of
enforcement of their agreement to submit Disputes to arbitration and of any
award of the Arbitrator.

                  9.       ASSIGNMENT. Neither this Agreement nor the rights or
obligations hereunder shall be assignable by either party hereto, by operation
of law or otherwise, without the prior written consent of the other party
hereto, and any purported assignment shall be null and void. Subject to the
foregoing, this Agreement shall inure to the benefit of and be binding upon the
parties hereto and their respective successors and assigns.

                  10.      FORCE MAJEURE/DELAY. No party will be responsible if
it is prevented from complying, either totally or in part, with any of the terms
or provisions of this Agreement by reason of an Event of Force Majeure (as
defined below), and such


                                      -5-
<Page>

party shall have no liability to the other party in connection therewith;
PROVIDED, that such party shall have a duty reasonably to mitigate, or cause to
be mitigated, any such failure to comply. As used in the Agreement, an "EVENT OF
FORCE MAJEURE" means any of the following: fires, floods, earthquakes, elements
of nature or acts of God; acts of war, terrorism, riots, civil disorders,
rebellions or revolutions; strikes, lockouts or labor difficulties; power
outages, equipment failures, computer viruses or malicious acts of third
parties; and laws, orders, proclamations, regulations, ordinances, demands or
requirements of governmental authorities.

                  11.      INDEMNIFICATION.

                  (a)      Platinum shall indemnify and hold harmless, to the
full extent permitted by law, St. Paul, its Post-closing Subsidiaries and their
respective officers, directors and employees ("ST. PAUL INDEMNITEES") from and
against any and all Losses of any of the St. Paul Indemnitees arising out of or
based upon any actions taken or refrained from being taken by any such St. Paul
Indemnitee at the direction of Platinum pursuant to this Agreement, or any
breach by Platinum of any of its covenants under this Agreement.

                  (b)      St. Paul shall indemnify and hold harmless, to the
full extent permitted by law, Platinum, its Post-closing Subsidiaries and their
respective officers, directors and employees ("PLATINUM INDEMNITEES") from and
against any and all Losses of any of the Platinum Indemnitees arising out of or
based upon the negligence or willful misconduct of any Person providing
Services, or any breach by St. Paul of any of its covenants under this
Agreement. Notwithstanding anything to the contrary in this Agreement, the
maximum amount of indemnifiable losses which may be recovered from St. Paul
shall under no circumstances exceed the aggregate fees paid to St. Paul by
Platinum pursuant to Section 1(d).

                  (c)      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.

                  12.      ADDITIONAL SERVICES. To the extent that, at the
request of Platinum or as required under the terms of this Agreement, St. Paul
or any of its Affiliates provides services to, or performs activities for the
benefit of, Platinum or any of its Affiliates in addition to the Services,
including without limitation pursuant to Sections 1(f) and 6 hereof, Platinum
shall promptly reimburse St. Paul for the actual cost to St. Paul or such
Affiliate, as the case may be, of providing such services or performing such
activities.

                  13.      ENTIRE AGREEMENT. This Agreement and the Formation
and Separation Agreement constitute the entire agreement, and supersede all
prior agreements and understandings (oral and written), by and among the parties
hereto with respect to the subject matter hereof.

                  14.      NO THIRD-PARTY RIGHTS. Nothing contained in this
Agreement, express or implied, establishes or creates, or is intended or will be
construed to establish or create, any right in or remedy of, or any duty or
obligation to, any third party other than Platinum's Subsidiaries.


                                      -6-
<Page>

                  15.      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 certified
mail, postage prepaid and return receipt requested, or by facsimile 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 St. Paul:
                           The St. Paul Companies, Inc.
                           385 Washington Street
                           St. Paul, Minnesota 55102
                           Attn.: General Counsel
                           Facsimile:  (410) 205-6967

                  With a copy to:

                           Donald R. Crawshaw
                           Sullivan & Cromwell
                           125 Broad Street
                           New York, New York  10004
                           Facsimile:  (212) 558-3588
                  If to Platinum:
                           Platinum Underwriters Holdings, Ltd.
                           [        ]
                           Hamilton HM 11
                           Bermuda
                           Attn.:   Secretary
                           Facsimile:  (441)  [                ]

                  With a copy to:
                           Linda E. Ransom
                           Dewey Ballantine LLP
                           1301 Avenue of the Americas
                           New York, New York 10019
                           Facsimile:  (212) 259-6576

                  16.      COUNTERPARTS. This Agreement may be executed in one
or more counterparts, each of which shall be deemed an original, but all of
which shall constitute one and the same instrument.

                  17.      AMENDMENT; MODIFICATION. The parties may by written
agreement, subject to any regulatory approval as may be required, (a) extend the
time for the performance of any of the obligations or other acts of the parties
hereto; (b) waive any inaccuracies in the documents delivered pursuant to this
Agreement, and (c) waive


                                      -7-
<Page>

compliance with or modify, amend or supplement any of the agreements contained
in this Agreement or waive or modify performance of any of the obligations of
any of the parties hereto. This Agreement may not be amended or modified except
by an instrument in writing duly signed on behalf of the parties hereto.

                  18.      WAIVER. No failure by any party to take any action or
assert any right hereunder shall be deemed to be a waiver of such right in the
event of the continuation or repetition of the circumstances giving rise to such
right, unless expressly waived in writing.

                  19.      SEVERABILITY. To the extent any provision of this
Agreement shall be invalid or unenforceable, it shall be considered deleted
herefrom and the remaining provisions of this Agreement shall be unaffected and
shall continue in full force and effect.

                  20.      SPECIFIC PERFORMANCE AND OTHER EQUITABLE RIGHTS. Each
of the parties recognizes and acknowledges that neither St. Paul nor Platinum
would contemplate the provision of Services hereunder unless this Agreement was
executed and that a breach by a party of any covenants or other commitments
contained in this Agreement will cause the other party to sustain injury for
which it would not have an adequate remedy at law for money damages. Therefore,
each of the parties agrees that in the event of any such breach, the aggrieved
party shall be entitled to the remedy of specific performance of such covenants
or commitments and preliminary and permanent injunctive and other equitable
relief in addition to any other remedy to which it may be entitled, at law or in
equity, and the parties further agree to waive any requirement for the securing
or posting of any bond in connection with the obtaining of any such injunctive
or other equitable relief.

                  21.      HEADINGS. Headings contained in this Agreement are
for reference purposes only and shall not affect in any way the meaning or
interpretation of this Agreement.

                  22.      DEFINITIONS; FORMATION AND SEPARATION AGREEMENT.
Capitalized terms used but not defined in this Agreement have the meanings
specified in the Formation and Separation Agreement.

                  23.      EFFECTIVENESS. This Agreement shall become effective
contingent upon the consummation of the Public Offering, without any further
action by either of the parties hereto.


                                      -8-
<Page>

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


                                      THE ST. PAUL COMPANIES, INC.

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


                                      PLATINUM UNDERWRITERS HOLDINGS, LTD.

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





                                      -9-
<Page>










                                      -10-