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                                                                   EXHIBIT 10.9

                        AMENDMENT TO LETTER OF EMPLOYMENT

         THIS AMENDMENT TO LETTER OF EMPLOYMENT ("Amendment") is made and
entered into by and between Ferdinand Colloredo-Mansfeld ("Employee") and CABOT
INDUSTRIAL PROPERTIES, L.P. ("Employer").

         WHEREAS, Employee and Employer entered into an amended letter of
employment, effective September 10, 1998 (the "Letter of Employment"), under
which Employee is to receive certain benefits if Employee's employment is
terminated under certain circumstances following a Change in Control (as defined
therein) (the "Change in Control Benefits"), with the payment of the Change in
Control Benefits to be made as soon as practicable following such termination;
and

         WHEREAS, the Change in Control Benefits, prior to required payroll tax
withholding or any adjustment in accordance with the provisions of Exhibit A to
the Letter Agreement, is an amount equal to three (3) times the sum of the rate
of the Employee's annual base compensation as in effect on the date of
termination (or as in effect on the date of the Change in Control, if higher)
plus the amount of the Employee's bonus for the year prior to the year in which
the Employee's employment terminates (the "Initial Benefit"); and

         WHEREAS, pursuant to the terms of the Agreement and Plan of Merger,
dated as of October __, 2001 (the "Merger Agreement"), Cabot Industrial Trust
("REIT") and Employer desire to have Rooster Acquisition Corp., a Delaware
corporation, merge with and into REIT with REIT as the surviving corporation
(the "Merger"); and

         WHEREAS, as a result of the contemplated Merger, Employee and Employer
mutually agree that it is in the best interest of both parties for the
definition of Change in Control, the timing of the payment of the Change in
Control Benefits, and the calculation of the Initial Benefit under the Letter of
Employment to be amended; and

         WHEREAS, Employee and Employer mutually agree that if the contemplated
Merger is either: (a) not effected or (b) not effected on or before April 30,
2002, this Amendment shall be without any force and effect and the definition of
Change in Control, the timing of the payment of the Change in Control Benefits,
and the calculation of the Initial Benefit under the Letter of Employment shall
at all times commencing immediately after the execution of this Amendment be the
definition of Change in Control and timing of payment of such benefits in effect
immediately prior to the execution of this Amendment.

         NOW, THEREFORE, for and in consideration of the mutual promises set
forth below, it is hereby agreed by and between the Employee and Employer as
follows:

         1.       The definition of Change in Control under the Letter of
Employment shall be amended in its entirety to read as follows:

         A "Change in Control" means the happening of any of the following:

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         (a)      the  effective  time of a  transaction  under  which the REIT
                  merges  into or  consolidates  with another entity,  sells or
                  otherwise  disposes of all or substantially all of its assets
                  or adopts a plan of liquidation,  provided,  however,  that a
                  Change in Control shall not be deemed to have occurred by
                  reason of a transaction,  or a substantially  concurrent or
                  otherwise  related series of  transactions,  upon the
                  completion of which 50% or more of the  beneficial  ownership
                  of the voting  power of the REIT,  the  surviving  corporation
                   or  corporation  directly or  indirectly controlling  the
                  REIT or the  surviving  corporation,  as the  case  may be,
                  is held by the same persons  (as  defined  below)  (although
                  not  necessarily  in the same  proportion)  as held the
                  beneficial  ownership of the voting power of the REIT
                  immediately  prior to the  transaction  or the substantially
                  concurrent or otherwise  related series of transactions,
                  except that upon the completion  thereof,  employees or
                  employee benefit plans of the REIT may be a new holder of such
                  beneficial  ownership;  provided,  further,  that any
                  transaction described in this paragraph (a) with an
                  "Affiliate"  of the REIT (as defined in the  Securities
                  Exchange Act of 1934, as amended (the "Exchange Act")) shall
                  not be treated as a Change in Control; or

         (b)      the "beneficial ownership" (as defined in Rule 13d-3 under the
                  Exchange Act) of securities representing 25% or more of the
                  combined voting power of the REIT is acquired, other than from
                  the REIT, by any "person" as defined in Sections 13(d) and
                  14(d) of the Exchange Act (other than any trustee or other
                  fiduciary holding securities under an employee benefit or
                  other similar stock plan of the REIT); or

         (c)      at any time during any period of two consecutive years,
                  individuals who at the beginning of such period were members
                  of the Board cease for any reason to constitute at least a
                  majority thereof (unless the election, or the nomination for
                  election by the REIT's shareholders, of each new trustee was
                  approved by a vote of at least two-thirds of the trustees
                  still in office at the time of such election or nomination who
                  were trustees at the beginning of such period).

         2.       The timing of the payment of the Change in Control Benefits
under the Letter of Employment shall be amended in its entirety to provide as
follows:

         The "lump sum payment" to be made pursuant to the terms of the Letter
of Employment shall be made on the earliest to occur of:

         (a)      the effective time of the Merger;

         (b)      the termination of the Merger Agreement as a result of an
                  injunction having been obtained against the Merger; or

         (c)      the 120th  day  following  the close of the  Tender  Offer as
                  contemplated  and set forth in the Merger Agreement.

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         3.       The  calculation  of the Initial  Benefit under the Letter of
                  Employment  shall be amended in its entirety to provide as
                  follows:

         The Initial Benefit shall be an amount equal to three (3) times the sum
         of the rate of the Employee's annual base compensation as in effect on
         the date of termination (or as in effect on the date of the Change in
         Control, if higher) plus the amount of the Employee's bonus for the
         year in which the Employee's employment terminates (provided if
         termination of employment does not occur until the year 2002, the bonus
         shall be the amount of bonus paid with respect to the year 2001).

         4.       In the event the contemplated Merger is either: (a) not
effected or (b) not effected on or before April 30, 2002, this Amendment shall
be without any force and effect and the definition of Change in Control, the
timing of the payment of the Change in Control Benefits, and the calculation of
the Initial Benefit under the Letter of Employment shall at all times
commencing immediately after the execution of this Amendment be the definition
of Change in Control and timing of payment of such benefits in effect
immediately prior to the execution of this Amendment.

         5.       Employee, intending to be legally bound and for and in
consideration of the benefits described in this Amendment, does for himself,
his heirs, executors, administrators, successors and assigns, hereby release
and forever discharge Employer, its successors, predecessors, parents,
subsidiaries, affiliates, assigns, directors, officers, agents and employees
and all persons, corporations or other entities who might claim to be jointly
and severally liable with them, from any and all actions, causes of action,
claims, demands, charges or suits of any kind whatsoever based upon, arising
out of or relating to this Amendment.

         6.       Employee acknowledges that Employee has freely and
voluntarily entered into this Amendment and agrees that he shall not institute
any legal proceedings either individually or as a class representative or
member against Employer as to any matter based upon, arising out of or relating
to this Amendment.

         7.       This Amendment shall be governed by and construed in
accordance with the laws of the State of Massachusetts.

         8.       Except as provided herein, each provision of this Amendment is
intended to be severable. If any term or provision is held to be invalid, void
or unenforceable by a court of competent jurisdiction for any reason whatsoever,
such ruling shall not affect the remainder of this Amendment.

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         IN WITNESS WHEREOF, the parties, intending to be legally bound, apply
their signatures voluntarily and with full understanding of the contents of this
Amendment and after having had ample time to review and study this Amendment.

         Signed and executed this 28th day of October, 2001.

WITNESS:                                 EMPLOYEE

                                         /s/ Ferdinand Colloredo-Mansfeld
                                         --------------------------------

WITNESS:                                 CABOT INDUSTRIAL PROPERTIES, L.P.

                                         By:  /s/ Robert E. Patterson
                                              -----------------------
                                         Title:  President

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