EXHIBIT 10.07

                                TOWER GROUP, INC.

                           COMMON SECURITY CERTIFICATE

         THIS COMMON SECURITY HAS NOT BEEN  REGISTERED  UNDER THE SECURITIES ACT
OF  1933,  AS  AMENDED,  AND MAY NOT BE  OFFERED,  SOLD,  PLEDGED  OR  OTHERWISE
TRANSFERRED EXCEPT PURSUANT TO AN EXEMPTION FROM REGISTRATION.

         THIS CERTIFICATE IS NOT TRANSFERABLE  EXCEPT IN COMPLIANCE WITH SECTION
8.1 OF THE DECLARATION (DEFINED HEREIN).

         THIS  COMMON  SECURITY  IS IN  REGISTERED  FORM  WITHIN THE  MEANING OF
TREASURY  REGULATIONS  SECTION  1.871-14(c)(1)(i)  FOR U.S.  FEDERAL  INCOME AND
WITHHOLDING TAX PURPOSES.

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                  Certificate Number C-1      403 Common Securities

                                December 21, 2004

             Certificate Evidencing Floating Rate Common Securities

                                       of

                         Tower Group Statutory Trust IV

         Tower Group  Statutory  Trust IV, a statutory  trust  created under the
laws of the State of Delaware (the "Trust"),  hereby certifies that Tower Group,
Inc. (the  "Holder") is the registered  owner of common  securities of the Trust
representing  undivided  beneficial  interests  in the  assets of the Trust (the
"Common Securities").  Subject to the Declaration (as defined below), the Common
Securities are  transferable  on the books and records of the Trust in person or
by a duly authorized attorney,  upon surrender of this Certificate duly endorsed
and in proper form for transfer.  The Common Securities  represented  hereby are
issued  pursuant  to, and the  designation,  rights,  privileges,  restrictions,
preferences and other terms and provisions of the Common Securities shall in all
respects be subject to, the  provisions of the Amended and Restated  Declaration
of Trust of the Trust  dated as of  December  21,  2004,  among  Michael H. Lee,
Francis M. Colalucci and Steven G. Fauth,  as  Administrators,  Chase  Manhattan
Bank USA,  National  Association,  as  Delaware  Trustee,  JPMorgan  Chase Bank,
National Association,  as Institutional  Trustee, Tower Group, Inc., as Sponsor,
and the holders from time to time of undivided beneficial interest in the assets
of the Trust including the designation of the terms of the Common  Securities as
set forth in Annex I to such amended and restated  declaration,  as the same may
be amended from time to time (the "Declaration").  Capitalized terms used herein
but not defined shall have the meaning given them in the Declaration. The Holder
is entitled to the  benefits of the  Guarantee  and the  Indenture to the extent
provided  therein.  The  Sponsor  will  provide a copy of the  Declaration,  the
Guarantee and the Indenture to the Holder without charge upon written request to
the Sponsor at its principal place of business.

         As set forth in the Declaration,  when an Event of Default has occurred
and is  continuing,  the rights of Holders  of Common  Securities  to payment in
respect of Distributions and payments upon Liquidation,  redemption or otherwise
are subordinated to the rights of payment of Holders of the Capital Securities.

         Upon  receipt  of  this  Certificate,   the  Holder  is  bound  by  the
Declaration and is entitled to the benefits thereunder.

         By acceptance  of this  Certificate,  the Holder  agrees to treat,  for
United States federal income tax purposes, the Floating Rate Junior Subordinated
Deferrable  Interest  Debentures  ("Debentures")  as indebtedness and the Common
Securities as evidence of undivided beneficial ownership in the Debentures.

         This  Common  Security  is  governed  by,  and  shall be  construed  in
accordance with, the laws of the State of Delaware, without regard to principles
of conflict of laws.



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         IN WITNESS WHEREOF, the Trust has duly executed this certificate.

                                        TOWER GROUP STATUTORY TRUST IV


                                        By:  /s/   Francis M. Colalucci
                                        -------------------------------
                                             Name: Francis M. Colalucci
                                             Title: Administrator

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                          [REVERSE OF COMMON SECURITY]

         Distributions payable on each Commonl Security will be identical to the
amount of Distributions payable on each Capital Security, which is at a variable
per annum rate of interest,  reset quarterly,  equal to LIBOR (as defined in the
Declaration) plus 3.40% (the "Coupon Rate") of the stated  liquidation amount of
$1,000 per Capital Security, such Coupon Rate being the rate of interest payable
on the  Debentures to be held by the  Institutional  Trustee.  Distributions  in
arrears for more than one quarterly period will bear interest thereon compounded
quaraterly at the then applicable Coupon Rate for each such quarterly period (to
the extent  permitted by  applicable  law).  The terms  "Distributions"  as used
herein includes cash  distributions,  any such compounded  distributions and any
Additional  Interest  payable  on the  Debentures  unless  otherwise  stated.  A
Distribution  is payable only to the extent that payments are made in respect of
the  Debentures  held  by  the  Institutional  Trustee  and to  the  extent  the
Institutional  Trustee  has funds  legally  available  in the  Property  Account
therefor.  The amount of  Distributions  payable for any period will be computed
for any full quarterly  Distribution  period on the basis of a 360-The  Interest
Rate for any Distribution Period will at no time be higher than the maximum rate
then permitted by New York law as the same may be modified by United States law.

         All  percentages   resulting  from  any   calculations  on  the  Common
Securities will be rounded, if necessary,  to the nearest one hundred-thousandth
of a percentage  point,  with five  one-millionths of a percentage point rounded
upward (e.g.,  9.876545% (or .09876545) being rounded to 9.87655% (or .0987655),
and all  dollar  amounts  used in or  resulting  from such  calculation  will be
rounded to the nearest cent (with one-half cent being rounded upward)).

         Except  as  otherwise  described  below,  Distributions  on the  Common
Securities  will be cumulative,  will accrue from the date of original  issuance
and will be payable  quarterly in arrears on March 15, June 15, September 15 and
December  15 of each year or if such day is not a  Business  Day,  then the next
succeeding  Business  Day (each  such  date,  a  "Distribution  Payment  Date"),
commencing on the Distribution  Payment Date in March 2005. The Debenture Issuer
has the  right  under  the  Indenture  to  defer  payments  of  interest  on the
Debentures,  so long as no  Indenture  Event  of  Default  has  occurred  and is
continuing,  by extending the interest  payment  period for up to 20 consecutive
quarterly periods (each an "Extension Period") at any time and from time to time
on the  Debentures,  subject to the  conditions  described  below,  during which
Extension  Period no interest  shall be due and  payable.  During any  Extension
Period, interest will continue to accrue on the Debentures, and interest on such
accrued interest will accrue at an annual rate equal to the Distribution Rate in
effect for each such Extension Period,  compounded  quarterly from the date such
interest  would have been payable were it not for the Extension  Period,  to the
extent  permitted  by law (such  interest  referred  to  herein  as  "Additional
Interest").  No  Extension  Period may end on a date  other than a  Distribution
Payment  Date. At the end of any such  Extension  Period,  the Debenture  Issuer
shall pay all interest then accrued and unpaid on the Debentures  (together with
Additional Interest thereon);  PROVIDED,  HOWEVER,  that no Extension Period may
extend  beyond the Maturity  Date.  Prior to the  termination  of any  Extension
Period, the Debenture Issuer may further extend such period,  provided that such
period  together  with all such  previous  and  further  consecutive  extensions
thereof shall not exceed 20 consecutive  quarterly periods, or extend beyond the
Maturity Date. Upon the termination of any Extension Period and upon the payment
of all accrued and unpaid interest and Additional Interest, the Debenture Issuer
may commence a new Extension Period, subject to the foregoing  requirements.  No
interest or  Additional  Interest  shall be due and payable  during an Extension
Period,  except at the end thereof,  but each installment of interest that would
otherwise  have been due and payable  during such  Extension  Period  shall bear
Additional  Interest.  During any Extension Period,  Distributions on the Common
Securities  shall be deferred for a period  equal to the  Extension  Period.  If
Distributions are deferred, the Distributions due shall be paid on the date that
the related Extension Period terminates,  to Holders of the Common Securities as
they appear on the books and records of the Trust on the record date immediately
preceding such date.  Distributions on the Common Securities must be paid on the
dates payable  (after giving effect to any Extension  Period) to the extent that
the Trust has funds  available  for the  payment  of such  distributions  in the
Property  Account of the Trust.  The Trust's funds available for Distribution to
the Holders of the Common  Securities will be limited to payments  received from
the Debenture Issuer.


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         The  Common   Securities   shall  be  redeemable  as  provided  in  the
Declaration.


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                                   ASSIGNMENT

         FOR VALUE RECEIVED,  the undersigned  assigns and transfers this Common
Security Certificate to:


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         (Insert assignee's social security or tax identification number)

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         (Insert address and zip code of assignee) and irrevocably appoints





                                                                         agent
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                           to transfer this Common  Security  Certificate on the
                           books of the Trust. The agent may substitute  another
                           to act for him or her.

                           Date:
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                           Signature:
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                           (Sign  exactly as your name appears on the other side
                           of this Common Security Certificate)

                           Signature:
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                           (Sign  exactly as your name appears on the other side
                           of this Common Security Certificate)

         Signature Guarantee(1)








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(1)      Signature  must be  guaranteed by an "eligible  guarantor  institution"
         that is a bank,  stockbroker,  savings and loan  association  or credit
         union,  meeting  the  requirements  of the  Security  registrar,  which
         requirements  include  membership or  participation  in the  Securities
         Transfer Agents  Medallion  Program  ("STAMP") or such other "signature
         guarantee  program" as may be determined  by the Security  registrar in
         addition to, or in substitution  for, STAMP, all in accordance with the
         Securities Exchange Act of 1934, as amended.

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