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                                                                    EXHIBIT 10.6

                     DARWIN PROFESSIONAL UNDERWRITERS, INC.
                            LONG TERM INCENTIVE PLAN
                    (AS AMENDED, EFFECTIVE NOVEMBER 11, 2005)

By action of the Board of Directors of Darwin Professional Underwriters, Inc.,
the Darwin Professional Underwriters, Inc. Long Term Incentive Plan has been
amended and restated in its entirety to read as set forth below, such amendment
and restatement to be effective as of November 11, 2005 and to be applicable to
awards made in respect of all calendar years beginning with calendar year 2003.

I.       Purpose

         The purposes of the Darwin Professional Underwriters, Inc. Long Term
         Incentive Plan (the "Plan") are to:

         -        Reward successful management of the business

         -        Support retention of key executives

         -        Provide a vehicle through which the Board of Directors of the
                  Company (the "Board") can base incentive compensation on the
                  Company's performance.

         The Plan consists of interests in successive annual profit pools (each,
         a "Profit Pool") to be established for each calendar year (each, a
         "Profit Pool Year") beginning in calendar year 2003. Each Participant
         (as defined herein) in a Profit Pool will be awarded a percentage
         interest in such Profit Pool (an "Award"). A payment in respect of an
         Award ("Payout") will be made in part following the end of the
         four-year period commencing with the Profit Pool Year (the "Year Four
         Payout"), in part following the end of the five-year period commencing
         with the Profit Pool Year (the "Year Five Payout"), and in part
         following the end of the six-year period commencing with the Profit
         Pool Year (the "Year Six Payout"), all as provided and subject to the
         terms and conditions provided herein.

         Payout amounts will be determined by the Committee (as defined herein),
         consistent with the terms hereof. The Plan is intended to produce
         Payouts consistent with long term profitability. Accordingly, negative
         balances in any Outstanding Profit Pool (as defined herein) or in any
         Closed Profit Pool (as defined herein) will affect positive balances in
         any Outstanding Profit Pools. The 2003 Profit Pool Year would be paid
         out in part following completion of the Darwin Group Financial
         Statements for the year ended December 31, 2006 (i.e., the Year Four
         Payout would be made in spring 2007), in part following completion of
         the Darwin Group Financial Statements for the year ended December 31,
         2007 (i.e., the Year Five Payout would be made in spring 2008), and in
         part following completion of the Darwin Group Financial Statements for
         the year ended December 31, 2008 (i.e., the Year Six Payout would be
         made in spring 2009).

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II.      Definitions

         In addition to the terms otherwise defined in this Plan, the following
         definitions are applicable to this Plan:

         (1)      AFFILIATE, when used with reference to any person, shall mean
                  another person that, directly or indirectly, through one or
                  more intermediaries, controls or is controlled by or is under
                  common control with the person specified. The term "control"
                  (including the terms "controlled by" and "under common control
                  with") means the ability, directly or indirectly, to direct or
                  cause the direction of the management and policies of the
                  person in question.

         (2)      AIHL INSURANCE COMPANIES means Capitol Indemnity Corporation,
                  Capitol Specialty Insurance Corporation, Platte River
                  Insurance Company, Darwin Select Insurance Company and Darwin
                  National Assurance Company.

         (3)      ALLEGHANY means Alleghany Corporation.

         (4)      BENEFICIARY means the person or persons designated, in a
                  written notice delivered to the Company, by the Participant to
                  receive the amount, if any, payable under the Plan upon the
                  Participant's death. If there is no such surviving
                  Beneficiary, any amounts due with respect to the Participant
                  shall be payable to the Participant's estate.

         (5)      CAUSE means, with respect to a Participant, (i) the commission
                  by such Participant of gross misconduct in connection with the
                  performance of any of such Participant's duties to the Company
                  or any Affiliate of the Company, (ii) willful failure by such
                  Participant to implement reasonable directives of the Board of
                  Directors, or the person(s) to whom such Participant reports,
                  after written notice of such failure to such Participant,
                  which failure is not corrected within 10 days following
                  delivery of such written notice, or (iii) such Participant's
                  conviction of a felony. Notwithstanding the foregoing, if a
                  Participant is a party to an Employment Agreement which
                  contains a definition of "Cause", such definition shall be
                  applicable for purposes of the Plan.

         (6)      CHANGE OF CONTROL EVENT means (i) prior to an IPO, (x) the
                  occurrence of any Person, other than Alleghany or an Affiliate
                  of Alleghany, owning directly or indirectly more than 50% of
                  the outstanding voting securities (weighted by voting power)
                  of the Company, or (y) a sale of more than 50% of the total
                  gross fair market value of the assets of the Company to any
                  Person other than Alleghany or an Affiliate of Alleghany, and
                  (ii) subsequent to an IPO, (x) the occurrence of any Person or
                  Group, other than Alleghany or an Affiliate of Alleghany,
                  owning directly or indirectly more than 50% of the outstanding
                  voting securities (weighted by

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                  voting power) of the Company, or (y) a sale of more than 50%
                  of the total gross fair market value of the assets of the
                  Company to any Person or Group other than Alleghany or an
                  Affiliate of Alleghany.

         (7)      CLOSED PROFIT POOL means any Profit Pool in respect of which
                  the final Profit Pool Amount has been determined (i.e., a
                  Profit Pool in respect of which a Year Six Payout has been
                  determined).

         (8)      COMMITTEE means the Compensation Committee of the Board or, if
                  no such committee exists, the entire Board.

         (9)      COMPANY means Darwin Professional Underwriters, Inc. or any
                  successor corporation.

         (10)     DARWIN GROUP means Darwin Group, Inc., or any successor
                  corporation.

         (11)     DARWIN GROUP FINANCIAL STATEMENTS means the most recently
                  available audited consolidated financial statements of Darwin
                  Group as prepared in accordance with generally accepted
                  accounting principles as in effect as of the date of
                  reference, as certified by Darwin Group's independent auditors
                  and, if required, filed with the Securities and Exchange
                  Commission; provided, however, that for any year for which the
                  results of the Company and the Subsidiaries of Darwin Group
                  are included in the consolidated financial statements of
                  Alleghany or for any year that any of the AIHL Insurance
                  Companies are not Subsidiaries of Darwin Group, as to such
                  AIHL Insurance Companies, "Darwin Group Financial Statements"
                  means the most recently available audited consolidated
                  financial statements of Alleghany as prepared in accordance
                  with generally accepted accounting principles as in effect as
                  of the date of reference, as certified by Alleghany's
                  independent auditors and filed with the Securities and
                  Exchange Commission.

         (12)     DISABILITY means the inability of a Participant to discharge
                  his or her duties to the Company or any Affiliate of the
                  Company due to physical or mental illness for one or more
                  periods totaling six months during any consecutive
                  twelve-month period.

         (13)     EMPLOYMENT AGREEMENT means an employment agreement, if any,
                  entered into between a Participant and the Company or any
                  Affiliate of the Company.

         (14)     GOOD REASON means a Participant's termination of employment
                  with the Company if and only if such termination shall be the
                  result of: (i) a material reduction, without such
                  Participant's consent, of such Participant's responsibilities;
                  or (ii) relocation of the principal executive offices of the
                  Company, without such Participant's consent, to a location
                  more than 25 miles from their current location in Farmington,

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                  Connecticut. Notwithstanding the foregoing, if a Participant
                  is a party to an Employment Agreement which contains a
                  definition of "Good Reason", such definition shall be
                  applicable for purposes of the Plan.

         (15)     GROUP has the meaning set forth in Rule 13d-5 under the
                  Securities Exchange Act of 1934, as amended, as of the date
                  hereof; provided, however, that no Person (including without
                  limitation Alleghany and any Affiliate of Alleghany) who holds
                  shares of Series B Preferred Stock of the Company, or who
                  holds shares of common stock of the Company acquired upon
                  conversion of shares of Series B Preferred Stock, shall be
                  deemed to be a member of a Group, notwithstanding such
                  Person's being party to a voting agreement or any other
                  agreement with other Persons who are holders of shares of
                  Series B Preferred Stock or of shares of common stock of the
                  Company acquired upon conversion of shares of Series B
                  Preferred Stock.

         (16)     IPO means the initial public offering of shares of common
                  stock of the Company pursuant to an effective registration
                  statement under the Securities Act of 1933, as amended, in
                  connection with which the shares of common stock of the
                  Company become listed on a U.S. national securities exchange
                  or traded on the Nasdaq National Market System.

         (17)     NEGATIVE BALANCE has the meaning set forth in Paragraph V.(a)
                  below.

         (18)     OUTSTANDING PROFIT POOL means any Profit Pool which is not a
                  Closed Profit Pool.

         (19)     PARTICIPANT means, with respect to the Profit Pool for any
                  Profit Pool Year, any member of the management of the Company
                  or any Affiliate of the Company who is designated by the
                  Committee to receive an Award in respect of such Profit Pool.

         (20)     PAYOUT has the meaning set forth in Paragraph I above.

         (21)     PAYOUT PROFIT POOL has the meaning set forth in Paragraph
                  V.(a) below.

         (22)     PERSON shall mean any natural person, corporation,
                  partnership, limited partnership, limited liability company,
                  joint venture, firm, association, trust, unincorporated
                  organization, government or governmental agency or any other
                  entity.

         (23)     POSITIVE CREDIT has the meaning set forth in Paragraph V.(a)
                  below.

         (24)     PROFIT POOL YEAR BUSINESS means business underwritten by the
                  Company and the Subsidiaries of Darwin Group during a Profit
                  Pool Year,

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                  and for Profit Pool Years prior to 2006, shall include the
                  business underwritten for the AIHL Insurance Companies
                  pursuant to the Underwriting Management Agreements.

         (25)     PROFIT POOL AMOUNT has the meaning set forth in Paragraph
                  IV.(c) below.

         (26)     RETIREMENT means the termination of a Participant's employment
                  with the Company and all Affiliates of the Company, at or
                  after reaching age 65, based on a decision by such Participant
                  to retire. Notwithstanding the foregoing, if a Participant is
                  a party to an Employment Agreement which contains a definition
                  of "Retirement", such definition shall be applicable for
                  purposes of the Plan.

         (27)     SERIES B PREFERRED STOCK means the Series B Convertible
                  Preferred Stock of the Company.

         (28)     SUBSIDIARY means, with respect to any person, (i) a
                  corporation of which shares of stock having ordinary voting
                  power (other than stock having such power only by reason of
                  the happening of a contingency) to elect a majority of the
                  board of directors or other managers of such corporation are
                  at the time owned, directly or indirectly, through one or more
                  intermediaries, by such person, or (ii) in the case of
                  unincorporated entities, any such entity with respect to which
                  such person has the power, directly or indirectly, to
                  designate more than 50% of the individuals exercising
                  functions similar to a board of directors.

         (29)     UNDERWRITING MANAGEMENT AGREEMENT means any underwriting
                  management agreement between the Company and any AIHL
                  Insurance Company in effect prior to 2006 whereby the Company
                  has been authorized to write D&O, E&O and/or professional
                  liability insurance for such AIHL Insurance Company.

         (30)     VESTED PERCENTAGE has the meaning set forth in Paragraph V.(b)
                  below.

III.     Administration and Awards

         (a)      Committee

                  The Plan shall be administered by the Committee. The Committee
                  shall have the authority, in its sole discretion, to (i)
                  interpret the Plan, adopt, amend and rescind rules and
                  regulations relating to the Plan and take all other action
                  necessary or advisable for the implementation and
                  administration of the Plan, (ii) designate employees who are
                  to be Participants in the Plan with respect to the Profit Pool
                  for each Profit Pool Year, (iii) determine the percentage
                  interest in a Profit Pool to be awarded to each Participant,
                  (iv) determine Payout amounts in respect of each

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                  Profit Pool, and (v) determine Payout amounts to be made to
                  each Participant in a Profit Pool.

                  Decisions and determinations of the Committee on matters
                  relating to the Plan shall be made in good faith and in
                  accordance with the terms of the Plan. All such decisions and
                  determinations of the Committee shall be conclusive. No member
                  of the Committee shall be liable for any action taken or
                  decision made in good faith relating to the Plan or any Awards
                  thereunder.

         (b)      Eligibility for Participation

                  Participants in the Profit Pool for each Profit Pool Year
                  shall be designated by the Committee. In making such
                  designations and in determining the percentage interest in
                  such Profit Pool to be awarded to each Participant,
                  consideration will be given to the functions and
                  responsibilities of the individual, past and potential
                  contributions to the Company's growth, the value of his or her
                  services to the Company and any other factors deemed relevant
                  by the Committee. It is the intention of the Company that
                  Awards representing 100% of the interests in the Profit Pool
                  for each Profit Pool Year will be made to Participants. The
                  Committee may, in its sole discretion, determine that previous
                  Awards of interests in a Profit Pool which are forfeited will
                  be reallocated among other Participants, with the terms and
                  conditions of such reallocations to be determined by the
                  Committee.

                  Each Participant selected to receive an Award in the Profit
                  Pool for a Profit Pool Year shall receive written notice of
                  his or her selection and of the percentage interest in the
                  Profit Pool represented by such Award.

IV.      Profit Pools

         (a)      Determination of Profit Pool Amounts Before 2006

                  In determining Profit Pools for Profit Pool Years 2003 through
                  and including 2005, each Profit Pool for a Profit Pool Year
                  shall represent an amount, positive or negative, equal to 20%
                  of (A) the sum of (i) Affiliates' Investment Income (which may
                  not be a negative number) for the Profit Pool Year and (ii)
                  Underwriting Profit (which may be a positive or negative
                  number), less (B) the Commission Shortfall (which may not be a
                  negative number), if any, for the Profit Pool Year. For
                  purposes of this Paragraph IV.(a), the following terms have
                  the following meanings, and each shall be computed on basis of
                  the Darwin Group Financial Statements:

                           AFFILIATES' INVESTMENT INCOME means, with respect to
                           a Profit Pool Year, (i) an amount equal to the
                           average amount of Affiliates' Investable Funds
                           (determined as the average of the twelve such

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                           amounts on the last day of each month of such Profit
                           Pool Year), multiplied by (ii) the average yield on
                           the 10-year Treasury Note for such year (determined
                           as the average of the yields on the 10-year Treasury
                           Note on the last day of each month of such year).

                           AFFILIATES' INVESTABLE FUNDS means, on the date of
                           measurement, an amount, determined in all respects on
                           a cash basis, equal to (i) net premiums received by
                           the AIHL Insurance Companies in respect of Profit
                           Pool Business for all Profit Pool Years before 2006
                           (net of paid acquisition costs, including
                           Underwriting Management Commission and Profit
                           Commission, and ceded reinsurance premiums,
                           commissions and expenses), less (ii) net losses and
                           net loss adjustment expense paid by the AIHL
                           Insurance Companies in respect of Profit Pool
                           Business for all Profit Pool Years before 2006.

                           UNDERWRITING PROFIT means, at any time of
                           determination, an amount equal to the profitability
                           or loss, before income taxes and investment income,
                           of the Profit Pool Year Business to the AIHL
                           Insurance Companies, taking into account, without
                           limitation, net premiums earned, reinsurance premiums
                           ceded, commissions on reinsurance ceded, paid losses
                           and loss adjustment expense, reserves for known
                           claims, reserves for incurred but not reported
                           claims, Commissions (as defined in the Underwriting
                           Management Agreements), and any other expenses (but
                           exclusive of Profit Commissions, as defined in the
                           Underwriting Management Agreements) incurred by the
                           AIHL Insurance Companies in respect of the Profit
                           Pool Year Business.

                           COMMISSION SHORTFALL means, with respect to any
                           Profit Pool Year other than the 2003 Profit Pool
                           Year, the excess, if any, of the Company's expenses
                           over the Underwriting Management Commission. The
                           UNDERWRITING MANAGEMENT COMMISSION with respect to a
                           Profit Pool Year means the aggregate Underwriting
                           Management Commission paid by the AIHL Insurance
                           Companies pursuant to the Underwriting Management
                           Agreements and shall be an amount equal to the lesser
                           of (i) the Company's expenses for the Profit Pool
                           Year and (ii) an amount equal to (x) 32% of the gross
                           premium earned for the Profit Pool Year Business less
                           (y) all premium taxes and other acquisition expenses
                           (other than Underwriting Management Commissions or
                           Profit Commissions paid to the Company pursuant to
                           the Underwriting Management Agreements) payable by
                           the AIHL Insurance Companies in respect of such
                           Profit Pool Year Business for the Profit Pool Year.
                           For the 2003 Profit Pool Year, COMMISSION SHORTFALL
                           means the amount (which may not be a negative number)
                           by which (i) an amount equal to (x) the Company's
                           expenses for the 2003 Profit Pool Year

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                           less (y) an amount equal to (A) 32% of gross premium
                           earned for the 2003 Profit Pool Year Business less
                           (B) all premium taxes and other acquisition expenses
                           (other than Underwriting Management Commissions or
                           Profit Commissions paid to the Company pursuant to
                           the Underwriting Management Agreements) payable by
                           the AIHL Insurance Companies in respect of the 2003
                           Profit Pool Year Business exceeds (ii) $8 million.

         (b)      Determination of Profit Pool Amounts Beginning in 2006

                  In determining Profit Pools for Profit Pools beginning with
                  and including calendar year 2006, each Profit Pool for a
                  Profit Pool Year shall represent an amount, positive or
                  negative, equal to 20% of (A) the Underwriting Profit for the
                  Profit Pool Year (which may be a positive or negative number),
                  less (B) 5% of the Net Premiums Earned for the Profit Pool
                  Year. For purposes of this Paragraph VI.(b), the following
                  terms have the following meanings, and each shall be computed
                  on basis of the Darwin Group Financial Statements.

                           UNDERWRITING PROFIT means, at any time of
                           determination, an amount equal to the profitability
                           or loss, before income taxes and investment income,
                           of the Profit Pool Year Business of the Company and
                           the Subsidiaries of Darwin Group, taking into
                           account, without limitation, net premiums earned,
                           reinsurance premiums ceded, commissions on
                           reinsurance ceded, paid losses and loss adjustment
                           expense, reserves for known claims, reserves for
                           incurred but not reported claims, commissions, and
                           any other expenses incurred in respect of the Profit
                           Pool Year Business.

                           NET PREMIUMS EARNED means the amount of the premiums
                           earned in respect of the Profit Pool Year Business,
                           less the unearned premiums ceded to third party
                           insurers and adjusted for any changes in the
                           provision for unearned premiums.

         (c)      Following completion of the Darwin Group Financial Statements
                  for each year beginning with calendar year 2003, the Committee
                  shall determine the amount represented by each Outstanding
                  Profit Pool (each such amount, a "Profit Pool Amount"), and,
                  promptly following such determination, the Committee shall
                  provide written notice to each Participant in an Outstanding
                  Profit Pool of the Profit Pool Amount for such Profit Pool.

V.       Payouts

         (a)      Subject to the terms and conditions provided herein, at the
                  time of the Year Four Payout for a Profit Pool, payment shall
                  be made in an amount equal to 70% of the Profit Pool Amount
                  (as then determined) for such

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                  Profit Pool; at the time of the Year Five Payout for a Profit
                  Pool, payment shall be made in an amount so that an aggregate
                  amount equal to 85% of the Profit Pool Amount (as then
                  determined) for such Profit Pool shall have been paid; and at
                  the time of the Year Six Payout for a Profit Pool, a final
                  payment shall be made so that an aggregate amount equal to
                  100% of the Profit Pool Amount (as then determined) for such
                  Profit Pool (a "Closing Profit Pool") shall have been paid.
                  All such Payouts shall be made no later than two and one-half
                  (2-1/2) months following the end of the year of the Payout
                  (i.e., the Four Year Payout - - for the 2003 Profit Pool Year
                  will be paid no later than March 15, 2007) unless
                  administratively impracticable, in which case payment shall be
                  made as soon as reasonably practicable.

                  Upon determination of a final Profit Pool Amount for a Closing
                  Profit Pool, any amounts theretofore paid in excess of the
                  final Profit Pool Amount shall constitute a negative Profit
                  Pool Amount for that Profit Pool, which shall then be a Closed
                  Profit Pool. No Participant shall be required to make any cash
                  payment to the Company in respect of any negative Profit Pool
                  Amount in a Closing Profit Pool; provided, however, that any
                  negative Profit Pool Amount shall be applied against
                  Outstanding Profit Pools. In determining the Profit Pool
                  Amount for a Profit Pool as to which a Payout amount for a
                  Year Four Payout, a Year Five Payout or a Year Six Payout is
                  being determined (a "Payout Profit Pool"), any negative Profit
                  Pool Amount for any Closed Profit Pool or for any Outstanding
                  Profit Pool (a "Negative Balance") shall be applied to reduce
                  the Payout made in respect of any Payout Profit Pool. To the
                  extent that a Negative Balance in respect of a Closed Profit
                  Pool or an Outstanding Profit Pool is applied to reduce a
                  Payout in respect of a Payout Profit Pool, such Negative
                  Balance shall be reduced by the amount of the Negative Balance
                  so applied to reduce the Payout in respect of such Payout
                  Profit Pool. If a Negative Balance for an Outstanding Profit
                  Pool is applied to reduce a Payout in respect of a Payout
                  Profit Pool, a positive credit (a "Positive Credit") will be
                  given to the extent that the Profit Pool Amount for the
                  Outstanding Profit Pool which gave rise to the reduced Payout
                  of such Payout Profit Pool improves in future years. The
                  Committee shall allocate Negative Balances and Positive
                  Credits in an equitable manner, with a view to providing long
                  term compensation commensurate with long term results. The
                  Committee shall allocate Negative Balances and Positive
                  Credits first to the oldest of the Payout Profit Pools and
                  last to the newest of the Payout Profit Pools. Determinations
                  made by the Committee with regard to allocations of Negative
                  Balances and Positive Credits shall be final and binding.

         (b)      Allocation of Payouts to Participants.

                  Each time that a Payout amount is finally determined in
                  respect of an Outstanding Profit Pool, each Participant in
                  such Outstanding Profit Pool

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                  shall receive a payment in respect of his or her Award in such
                  Profit Pool equal to (x) the aggregate Payout amount so
                  determined multiplied by (y) the percentage interest in the
                  Profit Pool represented by his or her Award, multiplied by (z)
                  the Participant's Vested Percentage with respect to such
                  Profit Pool.

                  Unless otherwise agreed in writing by the Company and a
                  Participant in a Profit Pool, for purposes hereof, VESTED
                  PERCENTAGE means, with respect to a Participant, 25% at the
                  end of the two-year period commencing with the Profit Pool
                  Year, 50% at the end of the three-year period commencing with
                  the Profit Pool Year, and 100% at the end of the four-year
                  period commencing with the Profit Pool Year, provided that a
                  Participant is employed by the Company on the applicable
                  vesting date.

                  Notwithstanding the foregoing, (i) in the event of the
                  termination of a Participant's employment with the Company (x)
                  by the Company, which is a termination for Cause, or (y) by
                  such Participant other than for Good Reason, and provided that
                  such termination is not as a result of death, Retirement or
                  Disability, then all such Participant's Awards in Outstanding
                  Profit Pools, whether vested or unvested prior to the date of
                  such termination, shall be forfeited, (ii) in the event of the
                  termination of a Participant's employment with the Company (x)
                  by the Company, which is not a termination for Cause or (y) by
                  such Participant for Good Reason, and provided that such
                  termination is not as a result of death, Retirement or
                  Disability, then, effective on the date of such termination,
                  such Participant's Vested Percentage with respect to all
                  Awards in Outstanding Profit Pools shall be 100%, (iii) in the
                  event of the termination of a Participant's employment as a
                  result of death, Retirement or Disability, then all such
                  Participant's Awards in Outstanding Profit Pools which are
                  unvested on the date of such termination shall be forfeited,
                  (iv) in the event of a Change of Control Event, then all
                  Participants' Vested Percentage with respect to all Awards in
                  Outstanding Profit Pools shall be 100%, effective on the date
                  of such Change of Control Event. The rules contained in
                  clauses (ii), (iii) and (iv) above shall not affect the timing
                  of the payments made to Participants in respect of Awards; any
                  such payments shall be made at the same time that Payouts for
                  such Profit Pools are made to other Participants in those
                  Profit Pools whose employment with the Company is continuing.
                  For these purposes, employment by any Affiliate of the Company
                  shall be deemed to be employment by the Company.

VI.      Miscellaneous

         (a)      Effective Date of the Plan

                  The Plan became effective as of January 1, 2003 with respect
                  to the 2003 Profit Pool Year. The terms and provisions of the
                  Plan as amended shall

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                  be applicable to each Profit Pool Year since the Plan became
                  effective (i.e., beginning with the 2003 Profit Pool Year).

         (b)      Rights to Awards

                  No person shall have any claim or right to receive Awards
                  under this Plan. Neither a Participant to whom Awards have
                  been made nor his or her designated Beneficiary or legal
                  representative shall have any right or interest in the Awards
                  until the Awards for the Profit Pool Year have been made and
                  Payouts in respect thereof shall have become due in accordance
                  with the provisions of Paragraph V hereof.

         (c)      Non-Assignability

                  The rights of a Participant under the Plan are not assignable
                  during his or her lifetime, except by will or by the laws of
                  descent and distribution.

         (d)      Right to Employment

                  Nothing in the Plan shall confer upon any Participant the
                  right to continue in the employ of the Company or any
                  Affiliate of the Company or affect the right of the Company or
                  any Affiliate of the Company to terminate the employment of
                  such Participant.

         (e)      Withholding Taxes

                  Plan payments are to be made in cash and shall be net of an
                  amount sufficient to satisfy any Federal, state and/or local
                  withholding or other employment tax requirements.

         (f)      Newly Eligible Employees

                  The Committee shall be entitled to make such rules,
                  regulations, determinations and Awards as it deems appropriate
                  in respect of any employee who becomes eligible to participate
                  in the Plan after the commencement of a Profit Pool Year.

         (g)      Amendment and Termination

                  The Plan may be amended or terminated by the Committee at any
                  time or from time to time, provided that no such amendment
                  shall adversely affect any Participant's rights or obligations
                  with respect to any Outstanding Profit Pools without such
                  Participant's consent. Notwithstanding the foregoing, the
                  Committee may (but shall not be obligated to) amend the Plan
                  from time to time so that the Plan does not constitute a
                  "non-qualified deferred compensation plan" within the meaning
                  of Section 409A of the Internal Revenue Code of 1986, as
                  amended, and no consent of any Participant shall be required
                  to any such amendment.

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         (h)      Beneficiaries

                  If a Participant dies prior to the Payout of Awards for a
                  Profit Pool Year, any funds due to the Participant shall be
                  paid to the Participant's Beneficiary.

         (i)      Funding

                  The Plan shall be unfunded. The Company shall not be required
                  to establish any special segregation of assets to assure
                  payments of Awards.

         (j)      Governing Law

                  All questions pertaining to the construction, validity and
                  effect of the provisions of the Plan shall be determined in
                  accordance with the law of the State of Delaware.

                                       12<PAGE>
                                                                    Exhibit 10.7

                          AMENDED TAX SHARING AGREEMENT

          AGREEMENT, dated as of January 1, 2005, by and between Alleghany
Insurance Holdings LLC, a Delaware limited liability company ("AIHL"), and
Darwin Professional Underwriters, Inc. ("Darwin').

                                   WITNESSETH:

          WHEREAS, AIHL is wholly-owned by Alleghany Corporation, a Delaware
corporation ("Alleghany"), and is treated as a "disregarded entity" for Federal
income tax purposes; and

          WHEREAS, Alleghany is the "common parent" corporation of an
"affiliated group" of corporations (the "Alleghany Group"), as those terms are
defined in Section 1504(a) of the Internal Revenue Code of 1986, as amended (the
"Code"), which group, by reason of Alleghany's ownership of AIHL, includes
Darwin, and any corporation that is or subsequently becomes a member of an
"affiliated group" of which Darwin would be the "common parent," as such terms
are defined in Section 1504(a) of the Code, if Darwin were owned by individuals
(Darwin and any current or future member of its affiliated group being referred
to herein as the "Darwin Group"); and

          WHEREAS, AIHL has agreed with Alleghany for determining on an
equitable basis the amount to be paid by AIHL to Alleghany on account of the
ownership by AIHL of any entity included in the Alleghany Group; and

          WHEREAS, AIHL and Darwin desire to agree on an equitable basis for
determining the amount to be paid by Darwin to AIHL on account of the inclusion
of the Darwin Group in the Alleghany Group; and that it may have under this
Agreement. Alleghany shall have full and sole responsibility and discretion in
handling, settling,

<PAGE>

compromising or contesting any tax audit or contest involving such Tax Claim;
provided, however, that at the time that Darwin is no longer a member of the
Alleghany Group, Alleghany shall keep Darwin informed as to the progress of any
tax audit or contest and, if requested by Darwin, shall consult with, and
consider in good faith any recommendation by, Darwin (or its counsel) concerning
the conduct of such tax audit or contest.

          1. Resolution of Disputes as to the Darwin Group's Hypothetical Tax.
In the event of a disagreement between the parties hereto as to the amount of
the Darwin Group's hypothetical tax for any taxable year covered by this
Agreement, such amount shall be determined by the independent certified public
accountants who audit the certified financial statements of Alleghany for such
taxable year, and the determination of such accountants shall be final and
binding on the parties hereto; provided, however, that if the independent
certified public accountants who audit the certified financial statements of
Alleghany for such taxable year are not permitted or are unwilling to resolve
any such disagreement, then Alleghany and Darwin shall submit such disagreement
to a mutually acceptable national accounting firm (which shall not be the
accountants who regularly audit the financial statements of Darwin), whose
decision shall be conclusive and binding on Alleghany and Darwin. Alleghany and
Darwin shall each pay one-half of the fees and expenses of such mutually
acceptable national accounting firm.

          2. Earnings and Profits and Characterization of Payments. Earnings and
profits of each member of the Alleghany Group shall be calculated by allocating
the federal income tax liability of the Alleghany Group to each member in
accordance with

                                       2

<PAGE>

the method described in Section 1552(a)(2) of the Code and the applicable
Treasury Regulations thereunder.

          3. Termination of Membership in the Alleghany Group.

          (a) If Darwin should cease to be a member of the Alleghany Group at
any time, Darwin and AIHL agree that for income tax purposes the taxable period
of the Darwin Group which began on January 1 of the calendar year in which
Darwin ceases to be a member of the Alleghany Group shall be terminated as of
the close of business on the date Darwin ceases to be a member of the Alleghany
Group (the "Termination Date") in accordance with Treasury Regulations Section
1.1502-76(b)(1) and items of income, gain, loss, deduction or credit (other than
transactions properly allocable thereunder to the portion of the day after the
Termination Date shall occur) shall be apportioned based upon a closing of the
books for income tax purposes in accordance with Treasury Regulation Section
1.1502-76(b), as reasonably applied by Alleghany. No election shall be made
under Treasury Regulation Section 1.1502-76(b)(2)(ii) (relating to ratable
allocation of a year's items), and Treasury Regulation Section
1.150276(b)(2)(iii) will be applied to ratably allocate the items (other than
extraordinary items, including, without limiting the generality of the
foregoing, compensation items) for the month which includes the Closing Date.
All amounts attributable to any deferred intercompany transactions (as defined
in Treasury Regulation Section 1.1502-13) any "excess loss accounts" (as defined
in Treasury Regulation Section 1.1502-19) and other similar items among or
involving the members of the Darwin Group required to be taken into account at
the time Darwin ceases to be a member of the Alleghany Group shall be taken into
account in computing the Darwin Group's hypothetical tax for the taxable period
that

                                       3

<PAGE>

includes the Termination Date. Darwin agrees to file all tax returns, handle the
contest of any audit and otherwise act for all Tax purposes consistent with the
provisions of this Section 7(a).

          (b) Except as otherwise expressly contemplated by this Agreement, from
and after the Termination Date, Darwin will not without the prior written
consent of Alleghany (which consent shall not be unreasonably conditioned,
delayed or withheld), directly or indirectly make, change or revoke, or permit
to be made, changed or revoked, any election or method of accounting with
respect to federal income taxes affecting the liability of the Darwin Group for
tax periods prior to the Termination Date or that is intended to be effective
prior to the Termination Date.

          (c) All of the obligations of Darwin under this Agreement shall
continue in full force and effect following the Termination Date notwithstanding
that neither Darwin nor the Darwin Group may be members of the Alleghany Group,
including without limiting the generality of the foregoing, Darwin's obligation
to pay AIHL any additional federal income taxes arising by reason of any
adjustments to the Darwin Group's hypothetical tax for any taxable year that
Darwin was a member of the Alleghany Group. All of the obligations of AIHL shall
be terminated effective as of the Termination Date, except the obligations of
AIHL under Sections 3(b), 3(e) and 9.

          (d) None of Darwin, the Darwin Group, or any affiliated group (within
the meaning of Section 1504(a) of the Code), which includes any member of the
Darwin Group shall claim in, or carryback to, any taxable year for which a
consolidated federal income tax return is or was filed by Alleghany any item of
loss, deduction or credit arising in any tax period beginning after the
Termination Date.

                                       4

<PAGE>

          (e) Notwithstanding that Darwin may not have been paid for all of the
net operating losses, net capital losses, credits against tax or other tax
deductions or benefits (the "Tax Benefits") generated while Darwin was a member
of the Alleghany Group or that the Tax Benefits of the Darwin Group following
the Termination Date may be less than the Tax Benefits immediately preceding the
Termination Date, neither AIHL nor any other member of the Alleghany Group shall
have any obligation to pay or otherwise compensate Darwin or any member of the
Darwin Group for or in respect of such Tax Benefits.

          4. Retention and Access to Tax Records.

          (a) Darwin shall, and shall cause the members of the Darwin Group, to
preserve and keep all information returns with respect to federal income taxes,
or any other similar reports, statements, declarations, or documents required to
be filed by, or furnished to, any member of the Darwin Group under the Code,
including any attachments, exhibits, or other materials submitted with any of
the foregoing, including any amendments or supplements to any of the foregoing,
any federal income tax return work papers, any books and records relating to or
effecting, federal income taxes, any documentation relating to any audit,
review, examination, or any other administrative or judicial proceeding with the
purpose of effect of redetermining federal income taxes, and any other books of
account or records required to be maintained under the Code or Treasury
Regulation or under any record retention agreement with the Internal Revenue
Service ("Tax Records") relating to the assets and activities of the Darwin
Group for tax periods for which any were members of the Alleghany Group for so
long as the contents thereof may become material in the administration of any
matter under the Code, but in

                                       5

<PAGE>

any event until the later of (i) the expiration of any applicable statutes of
limitation, and (ii) seven years after the Termination Date. If, prior to the
expiration of the applicable statute of limitation and such seven-year period,
Darwin reasonably determines that any Tax Records which it is required to
preserve and keep under this Section 8(a) are no longer material in the
administration of any matter under the Code, Darwin may dispose, or may permit
the members of the Darwin Group to dispose, of such records upon 90 days' prior
notice to Alleghany. Such notice shall include a list of the records to be
disposed of describing in reasonable detail each file, book, or other record
accumulation being disposed. Alleghany shall have the opportunity, at its cost
and expense, to copy or remove, within such 90-day period, all or any part of
such Tax Records.

          (b) Darwin shall, and shall cause each member of the Darwin Group to,
cooperate in good faith with AIHL (and AIHL's legal and accounting
representatives) (including by copying relevant records and providing access to
or making available relevant personnel) in connection with the preparation of
any federal consolidated income tax returns (including any amended consolidated
federal income tax returns), the determination of the Alleghany Group's own
liability for federal income taxes, the determination of any item or matter
effecting the Darwin Group's hypothetical tax for any year and any audit or
other examination by any taxing authority, or any judicial or administrative
proceedings relating to the determination of any item or matter effecting the
Darwin Group's hypothetical tax. Any information obtained pursuant to this
Section 9 shall be held in strict confidence by AIHL and shall be used solely in
connection with the reason for which it was requested.

                                       6

<PAGE>

          5. AIHL Liability. Provided that Darwin and the members of the Darwin
Group have performed each and every obligation under this Agreement (whether or
not material), AIHL shall be liable for, and shall indemnify and hold harmless
Darwin and each member of the Darwin Group from and against any liability for
federal income taxes of the Alleghany Group imposed by Subtitle A or F of the
Code or Chapter 43 of Subtitle D of the Code.

          6. Miscellaneous Provisions.

          (a) Entire Understanding. This Agreement contains the entire agreement
and understanding among the parties with respect to the subject matter hereof
and supersedes and preempts any prior understandings, agreements or
representations by or among the parties, written or oral, which may have related
to the subject matter hereof in any way.

          (b) Choice of Law. This Agreement shall be governed by and construed
in accordance with the laws of the State of New York applicable to agreements
made and to be performed entirely within such state.

          (c) Further Assurances. The parties hereto shall execute and deliver
such further instruments and do such further acts and things (including, without
limitation, by causing their subsidiaries to execute and deliver such
instruments and to do such acts and things) as may be required to carry out the
intent and purpose of this Agreement.

          (d) Fees and Expenses. All fees and expenses of the preparation of any
tax returns, any fees and expenses related to, or arising out of, the
examination of any such tax returns and all costs of defending any adjustments
or proposed adjustments, as

                                       7

<PAGE>

the case may be, which are attributable to the Darwin Group shall be allocated
by AIHL to Darwin, and the amounts so allocable to the Darwin Group shall be
paid by Darwin to AIHL promptly upon request.

          (e) Interest and Penalties. If any interest is to be paid or received
as a result of any tax deficiency or refund, or any penalties are imposed with
respect to the treatment of any item on any return or schedule, in each case
attributable to the Darwin Group, then such interest or penalty shall be
allocated by AIHL, and the amounts so allocable to the Darwin Group shall be
paid by Darwin to AIHL, or from AIHL to Darwin, as the case may be, promptly
following the demand therefore by any taxing authority or the receipt thereof by
Alleghany, as the case may be.

          (f) Allocations and Apportionments. Whenever any amount or item is
required to be apportioned or allocated pursuant to this Agreement, such amount
shall be allocated in good faith and a manner that is reasonable in view of all
applicable circumstances. However, any amount allocated or apportioned shall be
deemed correct absent bad faith or manifest error.

          (g) Third Party Beneficiary. AIHL and Darwin intend that Alleghany is
a third party beneficiary of this Agreement, entitled to enforce all of the
rights of AIHL and the obligations of Darwin hereunder as if it were a party
hereto. Notwithstanding the foregoing, Alleghany shall not be subject to any of
the obligations of AIHL, nor shall any of the rights of Darwin be enforceable
against Alleghany.

          (h) Interpretation of Terms. Unless otherwise indicated, the words and
concepts used in this Agreement shall be given the same definitions and meanings
ascribed to them by the Code or the Treasury Regulations. Any alteration,
modification,

                                       8

<PAGE>

addition, deletion, or other change in the applicable provisions of the Code or
the Treasury Regulations shall automatically be applicable to this Agreement
mutatis mutandis. Unless otherwise indicated, all references herein to a
particular section of the Code or the Treasury Regulations shall include any
successor provision designated by a different or additional section reference.

          (i) Subsidiary Tax Sharing Agreements. Darwin shall enter into tax
sharing agreements with each member of the Darwin Group ("Darwin Group
Agreements") which Darwin Group Agreements shall not contain any terms or
provisions inconsistent with this Agreement. In addition, to the extent that
this Agreement imposes any obligation on the Darwin Group, Darwin shall cause
the Darwin Group Agreements to also impose that obligation on each member of the
Darwin Group.

          (j) Amendment and Waiver. No modification, amendment or waiver of any
provision of this Agreement shall be effective unless such modification,
amendment or waiver is approved in writing by each of AIHL and Darwin. The
failure of any party to enforce any of the provisions of this Agreement shall in
no way be construed as a waiver of such provisions and shall not affect the
right of such party thereafter to enforce each and every provision of this
Agreement in accordance with its terms.

          (k) Successors and Assigns. This Agreement shall bind and inure to the
benefit of and be enforceable by AIHL and Darwin and each of their respective
successors, assigns, heirs and personal representatives. Except for the
assignment by AIHL of its rights and obligations to Alleghany, no party shall
have the right to assign all

                                       9

<PAGE>

or part of its rights and obligations under this Agreement without the consent
of the other party hereto.

          (l) Notices. All notices, requests and other communications pursuant
to this Agreement shall be in writing and shall be deemed to have been duly
given, if delivered in person or by courier, or sent by express, registered or
certified mail, postage prepaid, to AIHL or to Darwin at the address set forth
below:

          If to AIHL:

               Alleghany Insurance Holdings LLC
               c/o Alleghany Corporation
               7 Times Square Tower
               17th Floor
               New York, NY 10036
               Attention: Chairman

          with a copy to:

               Alleghany Corporation
               7 Times Square Tower
               17th Floor
               New York, NY 10036
               Attention: General Counsel

          If to Darwin:

               Darwin Professional Underwriters, Inc.
               9 Farm Springs Road Farmington
               Connecticut 06032
               Attention: Chairman

Any party may, by written notice to the other party hereto, change the address
to which notices to such party are to be delivered or mailed.

          (m) Descriptive Headings. The descriptive headings of this Agreement
are inserted for convenience only and do not constitute a part of this
Agreement.

                                       10

<PAGE>

          (n) Invalidity of Provisions. If any provision of this Agreement is or
becomes invalid, illegal or unenforceable in any respect, the validity, legality
and enforceability of the remaining provisions contained herein shall not be
affected thereby.

          (o) Effective Date. This Agreement shall be effective from and after
January 1, 2005 for all tax periods, whether before or after January 1, 2005.

                                       11

<PAGE>

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

                                        ALLEGHANY INSURANCE HOLDINGS LLC

                                        By:  /s/ Roger B. Gorham
                                             -----------------------------------
                                        Name Roger B. Gorham
                                             -----------------------------------
                                        Title: Senior Vice President
                                               ---------------------------------

                                        DARWIN PROFESSIONAL UNDERWRITERS, INC.

                                        By: /s/ John L. Sennott, Jr.
                                            ------------------------------------
                                        Name John L. Sennott, Jr.
                                             -----------------------------------
                                        Title:  SVP, CFO
                                                --------------------------------

                                       12

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