<PAGE>
                                                                   EXHIBIT 10.15

                          UNDERWRITING AGENCY AGREEMENT

THIS AGREEMENT is made effective December 1, 2001 between ALLIED WORLD ASSURANCE
COMPANY, LTD, (hereinafter referred to as the "Company") and IPCRe UNDERWRITING
SERVICES LIMITED (hereinafter referred to as the "Underwriting Agent").

WHEREAS,

         A.       The Company has been incorporated in Bermuda and is licensed
                  under The Insurance Act 1978 as a Class 4 Insurer; and

         B.       The Underwriting Agent has been incorporated in Bermuda and is
                  licensed under The Insurance Act 1978 as an Insurance Agent;

NOW, THEREFORE, IT IS HEREBY AGREED AS FOLLOWS:

1.       APPOINTMENT

Subject to the terms and conditions of this Agreement, the Underwriting Agent is
hereby appointed by the Company to solicit, bind, write and administer the
business described in Section

2. hereof. The Underwriting Agent hereby accepts such appointment and agrees to
perform faithfully the duties thereof to the best of its professional ability,
in accordance with the standard of care of a professional insurance underwriter,
and with that degree of knowledge, skill and judgment which is exercised by it
with respect to its own business and the business of its parent and insurance
and reinsurance affiliates. The word "Agreement" herein shall be understood to
include any and all Addenda attached in accordance with the terms and conditions
herein specified.

2.       AUTHORITY OF THE UNDERWRITING AGENT

Subject to compliance with the Underwriting Guidelines (as defined in Section
2.2) and the IPCRe Co-Insurance Limitations (as defined in Section 2.3), the
Underwriting Agent shall have the power to bind the Company on the Subject
Business described in Section 2.1 and, except as expressly limited elsewhere
herein, the Underwriting Agent shall have the authority to do, outside of the
United States of America (which, for purposes of this Agreement, shall mean the
50 states and the District of Columbia), all things reasonably necessary in the
conduct of such business in order to fulfill its obligations under this
Agreement.

         2.1      The business to be underwritten on behalf of the Company shall
                  be limited to property catastrophe treaty reinsurance
                  pertaining to losses wheresoever arising (the "Subject
                  Business").

         2.2      The Underwriting Agent may not bind the Company to any Subject
                  Business unless such Subject Business complies with each of
                  the following guidelines (the "Underwriting Guidelines"):

                  A. The annual original premium written (excluding
                  reinstatement premium) for Subject Business ceded to the
                  Company pursuant to reinsurance treaties entered into by the
                  Underwriting Agent on behalf of the Company shall not exceed
                  $60 million, in the aggregate, without the prior consent of an
                  executive officer of the Company;

                  B. The types of risks that may be included in the Subject
                  Business assumed by the Company pursuant to reinsurance
                  treaties entered into by the Underwriting Agent on behalf of
                  the Company are limited to property catastrophe treaty
                  reinsurance, and specifically excludes inward retrocessions
                  and per-risk business;
<PAGE>
                  C. The maximum limit of liability under reinsurance treaties
                  entered into by the Underwriting Agent on behalf of the
                  Company will be $12.5 million per program, it being understood
                  that where multiple programs are written for a single client
                  group of companies, the limit shall be applied separately to
                  each separate segment of risk, based on geographic zone or
                  line of business, provided that applying such separate limits
                  will not result in any significant correlation leading to
                  additional accumulation of risks related to any such client
                  group, and provided further that in no event shall the
                  aggregate risk limit associated with any individual geographic
                  zone (which zones are described in Addendum A to this
                  agreement) in which Subject Business risks are located exceed
                  $200 million per zone (the "Zonal Limit");

                  D. The reinsurance treaties entered into by the Underwriting
                  Agent on behalf of the Company must contain customary
                  exclusions no less favorable to the Company than the
                  exclusions contained in similar treaties underwritten on
                  behalf of IPCRe Limited;

                  E. The risks assumed by the Company pursuant to reinsurance
                  treaties entered into by the Underwriting Agent on behalf of
                  the Company may be located wheresoever arising, subject to no
                  territorial limits (other than the Zonal Limits); and

                  F. The maximum treaty period for any reinsurance treaty
                  entered into by the Underwriting Agent on behalf of the
                  Company is 3 years, and any treaty that is proposed to be
                  entered into for a longer period must be approved by an
                  executive officer of the Company.

         2.3      The Underwriting Agent shall authorize treaty participations
                  to brokers and other producers of Subject Business only:

                  A. On the condition that IPCRe Limited will assume at least an
                  equal amount of the identical risk on any treaty as will the
                  Company, and subject to contractual terms (including rates,
                  limits, net retention provisions, and other contractual terms)
                  that are no more favorable to IPCRe Limited than those
                  applicable to the Company, it being understood that (i) if the
                  broker or producer refuses, despite the Underwriting Agent's
                  reasonable best efforts, to accept such authorization, the
                  Underwriting Agent shall nevertheless be free to accept the
                  Subject Business on behalf of the Company so long as the terms
                  on which it is accepted otherwise comply with the terms of
                  this Agreement and (ii) where IPCRe Limited, for itself, is
                  precluded from entering into a given treaty because of
                  geographic or other limitations that would not preclude the
                  Company from entering into such treaty, the Underwriting Agent
                  may bind the Company to such treaty; and

                  B. To the extent that any such treaty would reflect the best
                  efforts of the Underwriting Agent to achieve consistent
                  proportionality, on a per treaty basis, between the overall
                  composition of the property catastrophe treaty reinsurance
                  businesses of the Company and of IPCRe Limited.

         Clauses A. and B. above are referred to as the "IPCRe Co-Insurance
         Limitations".

         2.4      Except as provided in Section 2.3A., the net retention of
                  IPCRe in respect of any Subject Business to which the Company
                  is bound pursuant to a treaty entered into by the Underwriting
                  Agent in accordance with this Agreement shall at all times
                  equal or exceed the net retention of the Company.
<PAGE>
3.       LIMITATIONS OF AUTHORITY

The Underwriting Agent shall have no power or authority other than as granted
and set forth herein and no other or greater power shall be implied from the
grant or denial of powers specifically mentioned herein.

         3.1      In addition to the other limitations expressly contained in
                  this Agreement, the Underwriting Agent has no authority to:

                  A. make, accept or endorse notes or otherwise incur any
                  liability which is not incurred in the ordinary course of
                  business of the Underwriting Agent on behalf of the Company
                  pursuant to the terms and conditions of this Agreement;

                  B. issue a guaranty, other than as permitted expressly in
                  writing by the Company; or

                  C. hold itself out as an agent of the Company in any other
                  manner, or for any other purposes, than as specifically
                  prescribed in this Agreement.

         3.2      The Underwriting Agent shall use no advertising material,
                  prospectus, proposal, or representation, either in general or
                  in relation to a particular product of the Company, unless
                  furnished by the Company for that purpose.

         3.3      The Underwriting Agent shall have no authority to appoint
                  sub-agents for the Company without prior written approval of
                  the Company, except that the Underwriting Agent may employ
                  American International Company Limited at its own expense to
                  assist it in the performance of any ancillary duties under
                  this Agreement.

         3.4      The Underwriting Agent shall have no authority to produce and
                  bind Subject Business for the Company to the extent that doing
                  so would result in the Company's having any "related person
                  insurance income" or "RPII" (as defined in Section 953(c)(2)
                  of the United States Internal Revenue Code of 1986, as amended
                  (the "Code")). In order to effectuate the foregoing, the
                  Underwriting Agent, in its capacity as agent for the Company,
                  will: (A) not write reinsurance for insurers that are "United
                  States shareholders" (as defined in Section 953(c) of the
                  Code; (B) in a case where the person or persons insured under
                  insurance policies that are to be reinsured cannot be
                  identified, reinsure risks affecting large populations in
                  order to minimize the portion of the Company's reinsurance
                  premiums that are attributable (directly or indirectly) to the
                  risks of any particular person that may be a United States
                  shareholder or persons related to such shareholder (within the
                  meaning of Section 953(c) of the Code); and (C), except with
                  the express written consent of the Company (which consent
                  shall be granted or withheld in the Company's sole and
                  absolute discretion), not write any reinsurance policy if the
                  Underwriting Agent knows, or has reason to know, that such
                  policy may (directly or indirectly) reinsure risks of a United
                  States shareholder or persons related to such shareholder
                  (within the meaning of Section 953(c) of the Code). If, and to
                  the extent that, any reinsurance treaty to which the
                  Underwriting Agent has bound the Company would otherwise
                  result in the Company's having any RPII, the Underwriting
                  Agent, on behalf of IPCRe Limited, hereby accepts retrocession
                  of the reinsured risk to the extent that the risk is (directly
                  or indirectly) the risk of a United States shareholder or a
                  person related to such a shareholder (within the meaning of
                  Section 953(c) of the Code).
<PAGE>
4.       UNDERWRITING AGENT'S RECOMMENDATIONS

The Underwriting Agent will recommend to the Company the institution,
prosecution, defense or maintenance of any legal proceedings in connection with
any matter pertaining to the Subject Business produced by the Underwriting Agent
on behalf of the Company.

5.       TERRITORY

The territory within which the Underwriting Agent shall operate is intended to
be principally Bermuda. This Agreement shall be performed and services provided
hereunder shall be rendered in all material respects in Bermuda, it being
understood that the Underwriting Agent may also perform certain functions under
this agreement through affiliates located in other jurisdictions outside of the
United States of America. The Underwriting Agent shall be the exclusive agent of
the Company for the Subject Business. The Underwriting Agent shall not, however,
have any right to represent the Company or act on its behalf within the United
States of America and shall not discharge any of its rights, duties and
obligations set forth in this Agreement from within the United States of
America. Furthermore, nothing contained in this Agreement shall prevent the
Company from soliciting, binding, writing and administering Subject Business by
and on its own behalf.

6.       UNDERWRITING SERVICES

The Underwriting Agent shall perform, from outside the United States of America,
the following underwriting services on behalf of the Company:

         6.1      Process submissions for property catastrophe treaty
                  reinsurance.

         6.2.     Rate, quote and execute property catastrophe reinsurance
                  treaties in accordance with the authority granted herein and
                  in conformity with Section 2, and, if appropriate, terminate
                  or cancel policies and issue notices of cancellation.

         6.3      Develop and maintain underwriting files, in customary form, on
                  behalf of the Company and which become the property of the
                  Company.

         6.4      Use the best of its professional ability and good faith,
                  acting in accordance with the standard of care of a
                  professional insurance underwriter, in the selection of risks
                  to be underwritten by the Company.

         6.5      Approve or deny any claim made against the Company under
                  property catastrophe reinsurance treaties executed by the
                  Underwriting Agent on behalf of the Company. All claims must
                  be reported to the Company by the Underwriting Agent in a
                  timely manner, and a copy of the claim file will be sent to
                  the Company at its request, or as soon as it becomes known
                  that the claim (A) has the potential to exceed $5 million or
                  (B) involves a coverage dispute.

7.       REPORTS & ACCOUNTS

         7.1      The Underwriting Agent shall provide the Company with access
                  to its management information systems, for the purpose of
                  reviewing data which relates to business transacted under this
                  Agreement.

         7.2      Monthly, the Underwriting Agent shall allow American
                  International Company Limited, or any other administrative
                  services provider to the Company, to take an extract from its
                  underwriting system to populate an accounting or other
                  analytical system selected by the Company or such
                  administrative services provider. The Underwriting Agent shall
                  maintain data on catastrophe accumulations relating to the
<PAGE>
                  Subject Business in a customary form and shall provide such
                  information to the Company, as and when requested.

         7.3      The Underwriting Agent shall use its best efforts to provide
                  other reports or analyses as may be reasonably requested by
                  the Company.

         7.4      Not later than 30 days after the last day of each calendar
                  quarter, the Underwriting Agent shall deliver to the Company a
                  computation of the unearned premium and outstanding loss
                  reserves, including reserves for losses incurred but not
                  reported ("IBNR") required to be maintained by the Company
                  with respect to business produced by the Underwriting Agent.
                  Such computations shall be made in accordance with Bermuda
                  statutory accounting principles and in the manner specified by
                  the Company. In addition, the Underwriting Agent shall furnish
                  semi-annually such supplementary underwriting and actuarial
                  statistics as may be required by the Company.

         7.5      The Underwriting Agent will instruct the producer of any
                  Subject Business produced for the Company to cause the premium
                  relating to such Subject Business to be deposited directly to
                  a premium account established by the Company.

         7.6      The Company shall pay any claims presented to it for payment
                  by the Underwriting Agent within 2 business days of receipt of
                  written notice from the Underwriting Agent stating the nature
                  and amount of the claim to be paid, and identifying the treaty
                  to which the claim relates.

8.       RECORDS

         8.1      The Underwriting Agent shall keep, in a manner and form
                  approved by or acceptable to the Company, true and complete
                  Books and Records of all the Company's business conducted
                  under and pursuant to this Agreement, including, but not
                  limited to, reinsurance treaties or contracts, underwriting,
                  reserves, premium and claim records. The Underwriting Agent
                  shall maintain all records with regard to the Company's
                  business separately from the records of other businesses for
                  which it may act as underwriting agent or any similar
                  capacity.

         8.2      The Company shall have the right at all times during the
                  Underwriting Agent's business hours, and at its own expense,
                  to inspect and to make copies of the Books and Records of the
                  Underwriting Agent (or any sub-agent employed by the
                  Underwriting Agent) relating to the services provided
                  hereunder. The term "Books and Records" shall mean all
                  materials, books and records and data in whatever form or
                  medium (i) furnished by the Company to the Underwriting Agent
                  in connection with the performance by the Underwriting Agent
                  of its obligations under this Agreement; (ii) generated by the
                  Underwriting Agent in connection with the performance by the
                  Underwriting Agent of its obligations under this Agreement;
                  (iii) that may be accessed by the Company or its
                  administrative agent or provided by the Underwriting Agent to
                  the Company or its administrative agent pursuant to Section
                  7.1, 7.2, 7.3 or 7.4; or (iv) that in any way pertain to the
                  performance of the obligations of the Underwriting Agent under
                  this Agreement, including books of account, reinsurance
                  treaties and other contracts entered into by the Underwriting
                  Agent on behalf of the Company and all correspondence related
                  thereto, underwriting files, claim and reserving files, data
                  on premium and claim payments and any and all
<PAGE>
                  materials, books and records and data relating to the
                  reinsurance treaties entered into by the Underwriting Agent on
                  behalf of the Company.

         8.3      All Books and Records kept by the Underwriting Agent in
                  connection with the reinsurance treaties entered into by the
                  Underwriting Agent on behalf of the Company shall be and
                  remain the sole property of the Company and will remain the
                  property of the Company following termination of this
                  Agreement, including all databases maintained by the
                  Underwriting Agent relating to the Companies' accounting,
                  insurance or other records and whether or not such data is
                  maintained on information systems owned by the Underwriting
                  Agent or the Companies or neither. The Underwriting Agent
                  shall create and maintain underwriting records on behalf of
                  Company in hard copy form and shall deliver such records to
                  the Company whenever requested by the Company or periodically
                  when the Underwriting Agent deems them to be no longer
                  required to perform its duties under this Agreement. All such
                  Books and Records shall be delivered to the Companies upon
                  termination of this Agreement. All data related to the
                  business of the Company and entered by the Underwriting Agent
                  into its computer systems shall be delivered to the Company in
                  electronic form.

         8.4      The provisions of this Section shall survive the termination
                  of this Agreement until all obligations are fully discharged.

9.       CURRENCY

All records of business transacted pursuant to this Agreement shall be
maintained in original currency.

10.      COMPENSATION

The Underwriting Agent's remuneration for all services performed under this
Agreement shall be its commission ("Agency Commission") calculated at the rate
of 6.5% of the gross premiums written (less return premiums and commissions) on
behalf of the Company. Prior to the end of each month, the Underwriting Agent
shall provide to the Company a statement of gross premiums written during the
prior month, converted into United States dollars at the then prevailing rates,
together with a calculation of the Agency Commission. The Company shall pay the
Agency Commission to the Underwriting Agent promptly thereafter.

11.      RELATIONSHIP

The Company and the Underwriting Agent are independent of one another, and as an
independent agent, the Underwriting Agent is acting in the ordinary course of
its business. Nothing in this Agreement shall be deemed to create: (i) a joint
venture or partnership between the parties; (ii) a relationship of employer and
employee; (iii) a relationship of principal and agent; or (iv) any relationship
other than independent parties contracting with each other solely for the
purpose of carrying out the provisions of this Agreement.

12.      LICENSING

The Underwriting Agent warrants that it now has and shall maintain during the
term of this Agreement the license or licenses necessary to administer the
business described in this Agreement. In the event that any license the
Underwriting Agent utilizes to fulfill the requirements of the Agreement
expires, terminates or is suspended for any reason, this Agreement may be
terminated immediately by the Company the Company may avail itself of any rights
provided under Section 13.
<PAGE>
13.      TERM & TERMINATION

         13.1     The term of this Agreement shall commence on December 1, 2001
                  and shall continue in force until December 2, 2004 (the
                  "Initial Term"). Thereafter, this Agreement shall continue in
                  force for successive one-year periods (each, a "One-Year
                  Renewal Term"), unless prior written notice to terminate shall
                  have been delivered by one party to the other party at least
                  90 days prior to the expiration date of the Initial Term or
                  any One-Year Renewal Term.

         13.2     Except as otherwise provided herein, this Agreement shall
                  terminate automatically upon the effective date of the sale,
                  transfer or merger of the Underwriting Agent's business.

         13.3     Termination of this Agreement shall not affect the rights and
                  obligations of the parties hereto as to transactions, acts or
                  things done by either party prior to the effective date of
                  termination.

14.      CONFIDENTIALITY

         14.1     The Underwriting Agent hereby acknowledges that, as a result
                  of its performance of services for the Company under this
                  Agreement, it has and will acquire non-public information with
                  respect to the Company and its affairs, including: (a)
                  information relating to the business, finances, methods of
                  operation, business plans, marketing strategies and other
                  information relating to the Company and (b) other trade
                  secrets and proprietary information of the Company
                  (hereinafter collectively referred to as "Confidential
                  Information").

         14.2     During the term of this Agreement, and at all times
                  thereafter, the Underwriting Agent shall, and shall cause each
                  of its directors, officers, employees and agents (such
                  Persons, collectively "Covered Persons") to, keep confidential
                  (to the extent required hereby) all Confidential Information
                  that any of them may obtain and not to use such Confidential
                  Information for any purpose other than in the course of the
                  performance of this Agreement.

         14.3     The foregoing restrictions shall not apply with respect to any
                  Confidential Information (i) previously known to the
                  Underwriting Agent through a source not bound by any
                  obligation to the Company to keep the Confidential Information
                  confidential, (ii) lawfully obtained by the Underwriting Agent
                  from a source other than the Company, which source is not
                  bound by any obligation to keep such Confidential Information
                  confidential, (iii) the disclosure of which to any director,
                  officer, employee or agent of the Underwriting Agent is
                  necessary to carry out the purposes of this Agreement,
                  provided, however, that such disclosure referred to in this
                  clause (iii) shall be limited to the extent reasonably
                  necessary to protect the rights of the Company with respect to
                  its Confidential Information, and that as a condition to
                  disclosing any Confidential Information to any person who is
                  not bound by a duty of confidentiality to the Underwriting
                  Agent and its clients, the Underwriting Agent shall require
                  that such person enter into a confidentiality agreement with
                  the Company on terms satisfactory to the Company, or (iv)
                  independently developed by the Underwriting Agent without
                  reference to the Confidential Information.
<PAGE>
         14.4     The Underwriting Agent may disclose any Confidential
                  Information if and as required as a result of any governmental
                  investigation, court order, subpoena, deposition,
                  interrogatory, request for documents, civil investigative
                  demand, or similar legal duress, and to the extent reasonably
                  necessary for the Underwriting Agent or any of its affiliates
                  to comply with applicable securities laws and regulations and
                  stock exchange requirements and the applicable regulations of
                  other regulatory agencies having jurisdiction over the
                  Underwriting Agent or any of its affiliates.

         14.5     Notwithstanding anything provided in this Section 14,
                  Confidential Information may be disclosed with the prior
                  written consent of the Board of Directors of the Company.

15.      INDEMNIFICATION

The Company hereby agrees to indemnify and hold the Underwriting Agent and each
of its directors, officers, servants, agents and employees, harmless from and
agree to defend each of them (collectively, "Indemnitees") from and against all
and any manner of liabilities, suits, claims, damages and expenses (other than
those arising out of the gross negligence or willful misconduct of any such
Indemnitees in the performance of any of the Underwriting Agent's obligations
hereunder) arising out of or in connection with this Agreement or the good faith
performance by the Underwriting Agent of its obligations hereunder.

16.      ARBITRATION

Any controversy or claim arising out of or relating to this Agreement, or the
breach thereof, shall be submitted to a panel of three arbitrators, to be
appointed by the American Insurance Association. Each such arbitrator shall be a
current or former senior official of a Bermuda insurance or reinsurance company
but shall not be associated with any of the parties to this Agreement. Any
arbitration hereunder shall take place in Bermuda, and shall be conducted in
accordance with the Rules of the American Arbitration Association. The decision
of a majority of the arbitrators shall be in writing, shall state reasons for
the award, and shall be final and not subject to appeal, and judgment upon the
award or determination rendered by the arbitrators may be entered in any court
having jurisdiction thereof or having jurisdiction over the parties or their
assets.

17.      ASSIGNMENT

No assignment of this Agreement by one party shall be valid unless authorized in
advance in writing by the other party hereto.

18.      ENTIRE AGREEMENT, AMENDMENT & WAIVER

         18.1     This Agreement constitutes the entire agreement between the
                  parties with respect to the appointment by the Company of the
                  Underwriting Agent to solicit, bind, write and administer
                  Subject Business, and supersedes and extinguishes any
                  warranty, representation or arrangement previously given or
                  made with respect thereto, other than those expressly set out
                  herein. The express terms hereof supersede any course of
                  performance or usage of the trade. This Agreement may not be
                  amended except in writing signed by each of the parties
                  hereto.

         18.2     Neither the failure nor delay on the part of any party in
                  exercising any right, remedy, power or privilege under this
                  Agreement shall operate as a waiver thereof, nor shall any
                  single or partial exercise of any right, remedy, power or
                  privilege preclude any other or further exercise of the same
                  or of any other right, remedy, power or privilege, nor shall
                  any waiver of any right or remedy, power or privilege with
<PAGE>
                  respect to any occurrence be construed as a waiver of such
                  right, remedy, power or privilege with respect to any other
                  occurrence. No waiver hereunder shall be effective unless it
                  is in writing and is signed by the party asserted to have
                  granted such waiver.

19.      NOTICES

All notices required or permitted to be given hereunder shall be in writing and
shall be given as follows:

         19.1     If given by the Company:

         Delivered to the Underwriting Agent at American International Building,
         29 Richmond Road, Pembroke HM 08, Attention: President, or to such
         other address as the Underwriting Agent may have subsequently specified
         to the Company in writing; or

         19.2     If given by the Underwriting Agent:

         Delivered to the Company at American International Building, 29
         Richmond Road, Pembroke HM 08, Attention: President, or to such other
         address as the Company may have subsequently specified to the
         Underwriting Agent in writing.

20.      SERVICE OF PROCESS

In the event any legal process or notice is served on the Underwriting Agent in
a suit or proceeding against the Company, the Underwriting Agent shall forthwith
forward such process or notice to the Company.

21.      REGULATORY NOTICES

The Underwriting Agent shall forward promptly to the Company all correspondence
pertaining to this Agreement received from any government regulatory agency.

22.      GOVERNING LAW

This Agreement shall be governed by and construed in accordance with the laws of
Bermuda, without reference to the principles of conflicts of law thereof. If any
suit is instituted by any of the parties to enforce any of the terms or
conditions of this Agreement, each of the parties hereby submits to the
exclusive jurisdiction of and venue in the courts of Bermuda.

23.      COUNTERPARTS

This Agreement may be executed in any number of counterparts, each of which
shall be an original with the same effect as if the signatures thereto and
hereto were upon the same instrument, and such counterparts together shall
constitute one and the same instrument.

24.      HEADINGS

The section headings contained herein are for convenience only and shall not
alter or limit or define the provisions hereof.

25.      SEVERABILITY

In the event that any word, sentence, paragraph, provision, section, subsection
or article of this Agreement is found to be void or voidable, the remainder of
this Agreement shall nevertheless be legal and binding with the same force and
effect as though the void or voidable parts were deleted.

<PAGE>

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be executed
in duplicate in Pembroke, Bermuda, on the date first written above.

For and on behalf of                       For and on behalf of
IPCRe Underwriting Services Limited        Allied World Assurance Company, Ltd


   /s/ S.Fallon               for             /s/ Michael Morrison
------------------------------             ------------------------------
James P. Bryce
President                                  President
<PAGE>
                                   ADDENDUM A

                                Geographic Zones

In writing Subject Business, the Underwriting Agent will divide (A) the United
States into eight geographic zones and (B) its other markets, including Europe
and Japan, into ten zones, as follows:

                               UNITED STATES ZONES
<TABLE>
<CAPTION>
         ZONE #                                ZONE                              STATES
         ------                                ----                              ------
         <S>                           <C>                   <C>
           1                           New England           Connecticut, Massachusetts, Maine, New
                                                             Hampshire, Rhode Island, Vermont

           2                           Atlantic              District of Columbia, Delaware, Florida,
                                                             Georgia, Maryland, North Carolina, New Jersey,
                                                             New York, Pennsylvania, South Carolina,
                                                             Virginia

           3                           Gulf of Mexico        Alabama, Louisiana, Mississippi, Texas

           4                           North Central         Illinois, Indiana, Kentucky, Michigan, Ohio,
                                                             Tennessee, Wisconsin, West Virginia

           5                           Midwest               Arkansas, Colorado, Iowa, Kansas, Minnesota,
                                                             Missouri, Montana, North Dakota, Nebraska, New
                                                             Mexico, Oklahoma, South Dakota, Wyoming

           6                           West                  Arizona, Idaho, Nevada, California, Oregon,
                                                             Utah, Washington

           7                           Alaska                Alaska

           8                           Hawaii                Hawaii
</TABLE>

                         NON UNITED STATES (OTHER) ZONES
<TABLE>
<CAPTION>
                 ZONE                                      COUNTRIES
                 ----                                      ---------
<S>                                     <C>
Northern Europe                         Europe, Scandinavia, UK, Ireland

Japan                                   Japan

Asia                                    Korea, China, Micronesia, Taiwan

Australia/NZ                            Australia, New Zealand

Central America and Caribbean           Belize, Costa Rica, El Salvador, Honduras,
                                        Mexico, Nicaragua, Panama, Bahamas, Bermuda,
                                        Cayman Islands, Greater Antilles, Lesser
                                        Antilles, Leeward Islands, Turks & Caicos,
                                        Windward Islands

South America                           Argentina, Bolivia, Brazil, Chile, Colombia,
                                        Ecuador, French Guiana, Guyana, Paraguay,
                                        Peru, Surinam, Uruguay, Venezuela

Africa and Middle East                  Africa, Bahrain, Cyprus, Egypt, Iran, Iraq,
                                        Israel, Jordan, Kuwait, Lebanon, Oman, Qatar,
                                        Saudi Arabia, South Yemen, Syria, UAR, Yemen

Canada                                  Canada

Worldwide                               WW Inc US, WW X USA

Other                                   East Europe (i.e., Warsaw Pact), any other area
</TABLE>

The Underwriting Agent has designated the above geographic zones which, based on
historic catastrophe loss experience reflecting actual catastrophe events and
property development patterns, it believes are most likely to absorb a large
percentage of losses from one catastrophic event. These zones have been
determined using computer modeling techniques and underwriting assessments. The
parameters of these geographic zones will be subject to periodic review and
change and upon any change, the Underwriting Agent shall promptly notify the
Company of such change and the revised geographic composition of each zone.
<PAGE>

The Underwriting Agent recognizes that events may affect more than one zone, and
to the extent the Underwriting Agent accepts reinsurance from a ceding insurer
with a loss exposure in more than one zone, the Underwriting Agent will consider
such potential loss in testing the zonal limits in all such affected zones. For
example, the program for a U.S. national insurance company typically will be
subject to limits and exposure in each U.S. zone. A program with worldwide
exposure will also be subject to limits and exposure in U.S. zones and other
zones around the world, as applicable. In instances such as the above, where the
Underwriting Agent accepts reinsurance from a ceding insurer with a loss
exposure in more than one geographic zone, the accepted exposure will be counted
against the zonal limit in each zone where exposure exists, regardless of the
probability of loss from such exposure. The Underwriting Agent and the Company
understand that this method of monitoring and aggregating zonal limit exposure
can result in a substantial "double counting" of exposure in determining the
utilization of zonal limits in each zone.