<PAGE>

                                                                   Exhibit 10.31

                               AMENDMENT TO LEASE

     THIS AMENDMENT TO LEASE (this "AMENDMENT") is entered into as of the 24th
day of July, 2000, by and between BCIA NEW ENGLAND HOLDINGS LLC, a Delaware
limited liability company with an address of One Boston Place, Boston,
Massachusetts 02108-4406 ("LANDLORD") and PRI AUTOMATION, INC., a Massachusetts
corporation, formerly known as Precision Robots, Inc., with an address of 805
Middlesex Turnpike, Billerica, Massachusetts 01821 ("TENANT").

                                    RECITALS

A.   Landlord is the owner of certain real property located and known as 805
     Middlesex Turnpike, Billerica, Massachusetts (the "LOT") and the building
     thereon (the "BUILDING") (the Lot, together with the Building and all other
     improvements thereon, are hereinafter collectively referred to as the
     "PREMISES");

B.   Reference is made to that certain lease dated as of May 5, 1994 entered
     into between The Prudential Insurance Company of America, as predecessor in
     interest to Landlord, as landlord (the "ORIGINAL Landlord"), and Precision
     Robots, Inc., as tenant, with respect to the Premises;

C.   Landlord is the current owner of the Premises and the current holder of the
     landlord's interest under the Lease, and Tenant is the current holder of
     the tenant's interest under the Lease;

D.   Pursuant to the Lease, Tenant has been, and is now, in occupancy of the
     Premises;

E.   Pursuant to the Lease, the term thereof is set to expire on July 31, 2001;

F.   Landlord and Tenant desire to amend the Lease in order to, among other
     things, extend the term of the Lease upon the terms and conditions set
     forth herein;

     NOW THEREFORE, for valuable consideration, the receipt and sufficiency of
which is hereby mutually acknowledged, Landlord and Tenant hereby agree as
follows:

                                   AGREEMENTS

     1.   CAPITALIZED TERMS. Each capitalized term appearing but not defined
          herein shall have the meaning, if any, ascribed to such term in the
          Lease.

     2.   RECITALS. The recitals above set forth are true and complete and are
          incorporated herein by reference.

<PAGE>

     3.   AMENDMENTS. As of the date hereof, the Lease is amended as follows:

          a.   LANDLORD. Throughout the Lease, the words "The Prudential
               Insurance Company of America" are hereby deleted and the words
               "BCIA New England Holdings LLC, a Delaware limited liability
               company" are hereby inserted in lieu thereof.

          b.   TENANT. Throughout the Lease, the words "Precision Robots, Inc."
               are hereby deleted and the words "PRI Automation, Inc., a
               Massachusetts corporation" are hereby inserted in lieu thereof.

          c.   REFERENCE DATA. In Exhibit 1 to the Lease (REFERENCE DATA):

               (i)  In the section thereof in which the term "Premises" is
                    defined, the words "consisting of 122,342 square feet (SF)"
                    are hereby deleted and the words "agreed to contain 122,342
                    square feet (SF)" are hereby inserted in lieu thereof.

               (ii) In the section thereof in which the term "Term" is defined,
                    the words "Seven (7) years" are hereby deleted and the words
                    "Seventeen (17) years" are hereby inserted in lieu thereof.

               (iii) In the section thereof in which the term "Rent" is defined,
                    the following language is hereby inserted at the end
                    thereof:

<TABLE>
<S>                                    <C>                    <C>
"Year 8 $19.50 per SF Net, Net, Net,   $2,385,669 per year;   $198,805.75 per month
Year 9 $19.50 per SF Net, Net, Net,    $2,385,669 per year;   $198,805.75 per month
Year 10 $19.50 per SF Net, Net, Net,   $2,385,669 per year;   $198,805.75 per month
Year 11 $19.50 per SF Net, Net, Net,   $2,385,669 per year;   $198,805.75 per month
Year 12 $19.50 per SF Net, Net, Net,   $2,385,669 per year;   $198,805.75 per month
Year 13 $23.50 per SF Net, Net, Net,   $2,875,037 per year;   $239,586.42 per month
Year 14 $23.50 per SF Net, Net, Net,   $2,875,037 per year;   $239,586.42 per month
Year 15 $23.50 per SF Net, Net, Net,   $2,875,037 per year;   $239,586.42 per month
Year 16 $23.50 per SF Net, Net, Net,   $2,875,037 per year;   $239,586.42 per month
Year 17 $23.50 per SF Net, Net, Net,   $2,875,037 per year;   $239,586.42 per month"
</TABLE>

          d.   EXPIRATION DATE. In ARTICLE I of the Lease (TERM), in the third
               (3rd) line of the first (1st) paragraph thereof, the date "July
               31, 2001" is hereby deleted and the date "July 31, 2011" is
               hereby inserted in lieu thereof.

          e.   TAXES. In ARTICLE II of the Lease (PAYMENT OF RENT), in Section
               2.2 thereof (Taxes), the second and third sentences thereof are
               hereby


                                                                               2

<PAGE>

               deleted effective as of August 1, 2000 and the following
               sentences are hereby inserted in place thereof as of such date:

               "Estimated payments by Tenant on account of Taxes shall be made
               on the first day of each and every calendar month during the Term
               of this Lease, in the fashion herein provided for the payment of
               fixed rent. The monthly amount so to be paid to Landlord shall be
               sufficient to provide Landlord by the time real estate tax
               payments are due with a sum equal to Tenant's required payment,
               as reasonably estimated by Landlord from time to time, on account
               of Taxes for the then current Tax Year as hereinafter defined.
               "Tax Year" shall mean a twelve (12) month period commencing on
               July 1 and falling wholly or partially within the Term. Once
               annually, Landlord shall advise Tenant of the amount of the tax
               bills for the prior Tax Year and the computation of Tenant's
               payment on account thereof. If estimated payments theretofore
               made by Tenant for the Tax Year covered by such bills exceed the
               required payment on account thereof for such Tax Year, Landlord
               shall credit the amount of overpayment against subsequent
               obligations of Tenant on account of Taxes (or promptly refund
               such overpayment if the Term of this Lease has ended and Tenant
               has no further obligation to Landlord); but if the required
               payments on account thereof for such Tax Year are greater than
               estimated payments theretofore made on account thereof for such
               Tax Year, Tenant shall pay the difference to Landlord as
               additional rent within thirty (30) days after being so advised by
               Landlord in writing, and the obligation to make such payment for
               any period within the Term shall survive the expiration or
               earlier termination of the Term."

          f.   INSURANCE. In ARTICLE II of the Lease (PAYMENT OF RENT), in
               Section 2.2.3 thereof (Insurance), the following shall be added
               to the end of the first sentence thereof:

               "; provided, however, that from and after August 1, 2000, Tenant
               shall provide Comprehensive Liability Insurance indemnifying
               Landlord and Tenant against all claims and demands for any injury
               to person or property which may be claimed to have occurred on
               the Premises or at the Property as follows: $5,000,000.00 per
               occurrence/$10,000,000.00 aggregate (combined single limit) for
               property damage, bodily injury or death."

          g.   UTILITIES. Section 2.3 of the Lease is hereby deleted and the
               following is hereby inserted in its place: "2.3 UTILITIES Tenant
               agrees to pay directly to the utility companies providing
               utilities to the Premises all charges for utilities consumed at
               the Premises, including without limitation, gas, electricity, and
               water and sewer charges."


                                                                               3

<PAGE>

          h.   ADDITIONAL COVENANTS. In ARTICLE III of the Lease (ADDITIONAL
               COVENANTS OF TENANT):

               (i)  In Section 3.1.2 thereof, (A) the first sentence thereof is
                    hereby amended to insert the words: "the roof and" before
                    the word "both", (B) in the fourth sentence thereof, the
                    phrase "make all repairs to the Building" is hereby replaced
                    by the phrase: "make all repairs and replacements to the
                    Premises except the Landlord's Repair Obligations, as
                    defined below," and (C) the last sentence thereof is hereby
                    deleted and replaced with the following:

                    "Notwithstanding anything to the contrary herein contained,
                    except as otherwise provided in this Lease, Landlord agrees
                    to perform the following ("Landlord's Repair Obligations"):
                    (a) to keep in good order, condition and repair the
                    Structure, as defined below, of the Building and (b) to
                    replace the roof of the Building and the HVAC system of the
                    Building when and if required in Landlord's sole reasonable
                    judgment. If, during the Term of this Lease, Landlord shall
                    make a capital expenditure for replacement of the HVAC
                    system of the Building, then, (1) to the extent that any
                    individual capital expenditure for such purpose shall be
                    less than $25,000.00 or any set of capital expenditures for
                    such purpose shall be less than $50,000.00 in any calendar
                    year, Tenant shall pay to Landlord the amount thereof as
                    additional rent hereunder within thirty (30) days of written
                    notice thereof and (2) to the extent that any individual
                    capital expenditure for such purpose shall exceed $25,000.00
                    or any set of capital expenditures for such purpose shall
                    exceed $50,000.00 in any calendar year, Tenant shall pay to
                    Landlord as additional rent hereunder, in equal monthly
                    installments for the remainder of the Term, from and after
                    the date of such expenditure(s), an amount for each such
                    calendar year equal to the annual charge-off of such capital
                    expenditure. Annual charge-off shall be determined by
                    dividing the original capital expenditure or expenditures
                    PLUS an interest factor, reasonably determined by Landlord,
                    as being the greater of (a) the per annum interest rate then
                    being charged for long-term mortgages by institutional
                    lenders on like properties within the locality in which the
                    Property is located or (b) twelve percent (12%) per annum,
                    by the number of years of useful life of the capital
                    expenditure or expenditures; and the useful life shall be
                    determined reasonably by Landlord in accordance with
                    generally accepted accounting principles and practices in
                    effect at the time of making such expenditure or
                    expenditures. As used herein the term "Structure" means the
                    load bearing portions of the walls, columns, beams, concrete
                    slab, footings, and structural beams of the roof, in each
                    case necessary to preserve the load bearing capacity
                    thereof, and the outer facade of the outer walls
                    (specifically excluding all windows, window casings, glass,
                    and doors)."


                                                                               4

<PAGE>


               (ii) The following is hereby inserted at the end of Section 3.3:
                    "If Tenant assigns this Lease or sublets or otherwise
                    permits occupancy of the Premises or any portion thereof and
                    Landlord consents to the same, Tenant shall pay to Landlord
                    as additional rent, fifty percent (50%) of the amount, if
                    any, by which (a) any and all compensation received by
                    Tenant as a result of such assignment or sublease, or other
                    occupancy, net of reasonable expenses actually incurred by
                    Tenant in connection with such assignment or sublease or
                    other occupancy (with fit-up costs and brokerage fees being
                    amortized without interest over the remaining Term (or, with
                    respect to fit-up costs, the useful life thereof, if greater
                    than the remaining Term) and with such amortization and such
                    excess payments being recalculated upon any extension or
                    renewal of the Term hereof) exceeds (b) in the case of an
                    assignment, the Rent under this Lease, and in the case of a
                    sublease or other occupancy, the portion of the Rent
                    allocable to the portion of the Premises subject to such
                    subletting or other occupancy. Such payments shall be made
                    on the date the corresponding payments under this Lease are
                    due."

          i.   RIGHTS OF MORTGAGEES. In ARTICLE VII of the Lease
               (MISCELLANEOUS), Section 7.2 thereof is hereby amended and
               restated to read in its entirety as follows:

     7.2  RIGHTS OF MORTGAGEES.

          7.2.1 GENERAL. Provided Tenant receives a fully-executed original of
               the SNDA, as defined below, or a similar instrument reasonably
               acceptable to Tenant, this Lease shall be subject and subordinate
               to the lien and terms of any mortgage, deed of trust or ground

               lease or similar encumbrance (collectively, a "Mortgage", and the
               holder thereof from time to time the "Holder") from time to time
               encumbering the Premises, whether executed and delivered prior to
               or subsequent to the date of this Lease; provided, however, that
               the Holder may at any time elect to subordinate the lien and
               terms of any such Mortgage to this Lease. If this Lease is
               subordinate to any Mortgage and the Holder or any other party
               shall succeed to the interest of Landlord pursuant to the
               Mortgage (such Holder or other party, a "Successor"), Tenant
               shall attorn to the Holder or Successor and this Lease shall
               continue in full force and effect between the Holder or Successor
               and Tenant. Tenant agrees to execute such instruments of
               subordination or attornment in confirmation of the foregoing
               agreement as the Holder or Successor reasonably may request. With
               respect to each Mortgage encumbering the Premises from time to
               time during the Term, Tenant agrees to execute a subordination,
               non-disturbance and attornment agreement ("SNDA") in
               substantially the form attached hereto as EXHIBIT C, and Landlord
               shall cause the current Holder of


                                                                               5

<PAGE>

               the current Mortgage, and make reasonable efforts to cause any
               future Holder of any future Mortgage, to execute same, and upon
               any such execution Landlord shall deliver such executed SNDA to
               Tenant.

          7.2.2 ASSIGNMENT OF RENTS AND TRANSFER OF TITLE. With reference to any
               assignment by Landlord of Landlord's interest in this Lease, or
               the rents payable hereunder, conditional in nature or otherwise,
               which assignment is made to the Holder of a Mortgage on property
               which includes the Premises, Tenant agrees that the execution
               thereof by Landlord, and the acceptance thereof by the Holder of
               such Mortgage shall never be treated as an assumption by such
               Holder of any of the obligations of Landlord hereunder unless
               such Holder shall, by notice sent to Tenant, specifically
               otherwise elect and, except as aforesaid, such Holder shall be
               treated as having assumed Landlord's obligations hereunder only
               upon foreclosure of such Holder's Mortgage and the taking of
               possession of the Premises.

               (a)  In no event shall the acquisition of Landlord's interest in
                    the Premises by a purchaser which, simultaneously therewith,
                    leases Landlord's entire interest in the Premises back to
                    the seller thereof be treated as an assumption by operation
                    of law or otherwise, of Landlord's obligations hereunder,
                    but Tenant shall look solely to such seller-lessee, and its
                    successors from time to time in title, for performance of
                    Landlord's obligations hereunder. In any such event, this
                    Lease shall be subject and subordinate to the lease to such
                    purchaser. For all purposes, such seller-lessee, and its
                    successors in title, shall be the Landlord hereunder unless
                    and until Landlord's position shall have been assumed by
                    such purchaser-lessor. Landlord shall, however, make
                    reasonable efforts to cause such purchaser-lessor to execute
                    an SNDA with Tenant substantially in the form of EXHIBIT C
                    hereto, and upon any such execution Landlord shall deliver
                    such executed SNDA to Tenant.

               (b)  Except as provided in subsection (a) above, in the event of
                    any transfer of title to the Premises by Landlord, Landlord
                    shall thereafter be entirely freed and relieved from the
                    performance and observance of all covenants and obligations
                    hereunder which accrue after the date of such transfer.

          7.2.3 NOTICE TO MORTGAGEE. After receiving written notice from
               Landlord of any Holder of a Mortgage which includes the Premises,
               no


                                                                               6

<PAGE>

               notice from Tenant to Landlord alleging any default by Landlord
               shall be effective unless and until a copy of the same is given
               to such Holder (provided Tenant shall have been furnished with
               the name and address of such Holder), and the curing of any of
               Landlord's defaults by such Holder shall be treated as
               performance by Landlord.

          j.   TENANT'S PREPARATION OF PREMISES. In ARTICLE VIII of the Lease
               (LEASEHOLD IMPROVEMENTS):

               (i)  In the last paragraph of Section 8.1 of the Lease
                    (Landlord's Work), the $75,000 payment thereunder shall only
                    be due and payable by Tenant if (a) Tenant is in default
                    under the Lease beyond all applicable notice and cure
                    periods, if any, and (b) Landlord exercises any of its
                    remedies as set forth in Article V.

               (ii) Section 8.2 (Tenant's Preparation of the Premises) is hereby
                    amended to insert the following language at the end of the
                    first paragraph thereof: "The foregoing provisions of this
                    Section 8.2 shall be applicable to Tenant's initial fit up
                    of the Premises at the commencement of the Term. Commencing
                    on August 1, 2000, Landlord shall provide Tenant with a
                    second leasehold improvement allowance (the "Second
                    Leasehold Improvement Allowance") of an amount not to exceed
                    $428,197.00 in the aggregate for painting, carpeting,
                    reconfiguring architecture, engineering and other costs
                    within thirty (30) days of presentation of invoices to
                    Landlord in reasonable detail. Any of the Second Leasehold
                    Improvement Allowance for which disbursement requests have
                    not been made by December 31, 2001 shall be forfeited by
                    Tenant and Landlord shall have no further obligation with
                    respect thereto.

               (iii) The following is hereby inserted into the Lease as a new
                    Section 8.5:

                    "8.5 (Minor Alterations)

                    Notwithstanding any provision of this Lease to the contrary,
                    without the consent of Landlord, Tenant shall have the right
                    to make alterations to the interior of the Building so long
                    as (a) the cost of the same does not exceed $25,000 in any
                    calendar year, (b) the same does not adversely affect any
                    building system or the Structure of the Building."

               (iv) The following is hereby inserted as a new Section 8.6:

                    "8.6 (Reseal/Restripe)


                                                                               7

<PAGE>

                    Landlord agrees to use reasonable efforts to reseal and
                    restripe the Parking Lot adjoining the Building on or before
                    December 31, 2000 or if Landlord is unable to do so, then as
                    soon thereafter as is reasonably practicable."

          k.   NOTICES. ARTICLE IX of the Lease (NOTICES) is hereby amended as
               follows:

               (1)  to change the provision for notice to Landlord to the
                    following: "All notices for Landlord shall be addressed to
                    Landlord c/o Boston Capital Institutional Advisors LLC, One
                    Boston Place, Boston, Massachusetts 02108-4406, Attn: Karl
                    W. Weller, Managing Director, with a copy to Michael F.
                    Burke, Esq., Peabody & Arnold LLP, 50 Rowes Wharf, Boston,
                    Massachusetts 02110, or at such other place as may be
                    designated in written notice to Tenant"; and

               (2)  to delete the last sentence thereof and insert the following
                    in its place: "Unless otherwise directed in writing, all
                    rents shall be payable to Landlord c/o Fleet Lock Box,
                    Boston Capital, Box 31130, 99 Founder's Plaza, Hartford, CT
                    06150 or at such other place as Landlord shall from time to
                    time designate by notice to Tenant."

          l.   OPTION TO EXTEND. The following language is hereby inserted into
               the Lease as Article XIII:

                                  "ARTICLE XIII

                                OPTION TO EXTEND

     13.1 Provided that Tenant is not then in default hereunder beyond
          applicable cure periods, if any, Tenant shall have the option (the
          "Extension Option") to extend the Term of this Lease for an additional
          period of five (5) years commencing on August 1, 2011 and expiring on
          July 31, 2016 (the "Extension Term"). The Extension Option may be
          exercised by Tenant delivering to Landlord written notice thereof (the
          "Tenant Extension Notice") not earlier than February 1, 2010 and not
          later than July 31, 2010. The Extension Term shall be upon all of the
          same terms, covenants and conditions of this Lease as are in effect
          upon Tenant's exercise of such Extension Option, except (i) as to
          Annual Fixed Rent, which shall be determined as set forth below, and
          (ii) that Tenant shall have no further extension rights unless
          otherwise agreed to in writing by Landlord.

               Notwithstanding any provision herein to the contrary, the
          Extension Option shall be null and void upon the occurrence of any of
          the following events: (i) Tenant's failure to exercise the Extension
          Option within the aforementioned time period in accordance with the
          provisions set forth herein, or (ii) Tenant assigning its interest in
          this Lease, or (iii)


                                                                               8

<PAGE>

          Tenant at the time of such exercise having subleases in effect which
          total more than 25% of the square footage in the Building.

     13.2 If Tenant exercises the Extension Option as provided in Section 13.1
          above, then the annual fixed rental (Rent), as described in Section
          2.1 of this Lease and in Exhibit 1 to this Lease, for the Extension
          Term shall be the greater of (i) $2,875,037 or (ii) the Fair Market
          Rent. As used herein, the term "Fair Market Rent" means the Annual
          Fixed Rent as determined: (i) by agreement between Landlord and
          Tenant, negotiating in good faith, no later than thirty (30) days
          after Tenant's timely exercise of the Extension Option, or (ii) if
          Landlord and Tenant shall not have agreed upon the Fair Market Rent by
          said date as aforesaid (an "Impasse"), then Fair Market Rent for the
          Extension Term shall be fixed by means of an Appraisers' Determination
          as defined below.

     13.3 The term "Appraisers' Determination" refers to the following
          procedures and requirements:

          If an Impasse, as defined in Section 13.2 of this Lease, occurs, then,
          for the purpose of fixing the Fair Market Rent for the Extension Term,
          Landlord and Tenant shall agree upon an appraiser who shall be a
          member of the M.A.I. or Counselors of Real Estate (CRE) (or successor
          professional organizations) and shall have at least ten (10) years
          experience appraising rental values of comparable properties in the
          greater Boston market area.

          If Landlord and Tenant are not able to agree upon an appraiser by the
          date which is ten (10) days after such an Impasse (the "Appraiser
          Selection Deadline"), each of Landlord and Tenant shall, within ten
          (10) additional days, that is, by the date which is twenty (20) days
          after an Impasse, select an appraiser with the foregoing
          qualifications whereupon each of said appraisers shall, within five
          (5) days of their selection hereunder, select a third appraiser with
          the foregoing qualifications. The Fair Market Rent for the Extension
          Term shall thereafter be determined to be the amount equal to the
          average of the two appraisals which are closest in dollar amount to
          each other except that if all three appraisals are apart in equal
          amounts, then the appraisal which falls in the middle shall be the
          Fair Market Rent for the Extension Term. If either party fails to
          select an appraiser by the Appraiser Selection Deadline, then the
          appraiser selected by the other party, if selected by the Appraiser
          Selection Deadline, shall be the sole appraiser. Landlord and Tenant
          shall share equally the expense of any and all appraisers. The
          appraiser(s) shall be obligated to make a determination of Fair Market
          Rent within thirty (30) days of the appointment of either the single
          appraiser (if only one) and within thirty (30) days of the appointment
          of the third appraiser (if three are so appointed). In determining the
          Fair Market Rent for the Extension Term, the appraisers shall
          consider, among other things, the then current arms length basic rent


                                                                               9

<PAGE>

          being charged to tenants for comparable properties in the greater
          Boston market area. The appraisers shall not have the right to modify
          any provision of this Lease and shall only determine the Fair Market
          Rent which shall constitute the annual fixed rent (Rent) under this
          Lease for the Extension Term.

          m.   EXHIBIT C attached to this Amendment is hereby inserted into the
               Lease as EXHIBIT C thereto.

4.   BROKERS. Landlord and Tenant each represent that there are no brokers
     involved with respect to this Amendment other than Meredith & Grew
     Incorporated and Spaulding & Slye/Colliers and each party agrees to
     indemnify, defend and hold harmless the other with respect to any other
     broker in connection herewith. Landlord shall be responsible for any
     commission due to Meredith & Grew Incorporated and Spaulding &
     Slye/Colliers with respect to the transaction contemplated by this
     Amendment.

5.   EFFECTIVE DATE. The parties agree that this Amendment shall be effective
     from and after the date hereof and not to any period of time prior thereto.
     To the extent this Amendment contains language which purports to amend the
     Lease with respect to periods of time prior to the date hereof, such
     language is for clarification purposes only and shall not be deemed to
     change the obligations of the parties with respect thereto. In no event
     shall this Amendment be construed to impose any liability on Landlord for
     any period of time preceding its ownership of the Premises.

6.   RATIFICATION OF LEASE PROVISIONS. Except as otherwise expressly amended,
     modified and provided for in this Amendment, Tenant hereby ratifies all of
     the provisions, covenants and conditions of the Lease, and such provisions,
     covenants and conditions shall be deemed to be incorporated herein and made
     a part hereof and shall continue in full force and effect.

7.   ENTIRE AMENDMENT. This Amendment contains all the agreements of the parties
     with respect to the subject matter hereof and supersedes all prior dealings
     between the parties with respect to such subject matter.

8.   BINDING AMENDMENT. This Amendment shall be binding upon, and shall inure to
     the benefit of the parties hereto, and their respective successors and
     assigns.

9.   GOVERNING LAW. This Amendment shall be governed by the law of the state in
     which the Premises is located and the parties hereby submit to the
     jurisdiction of such state.

10.  SEVERABILITY. If any clause or provision of this Amendment is or should
     ever be held to be illegal, invalid or unenforceable under any present or
     future law applicable to the terms hereof, then and in that event, it is
     the intention of the parties hereto that the remainder of this Amendment
     shall not be affected thereby, and that in lieu of each such clause or
     provision of this Amendment that is illegal, invalid or unenforceable, such
     clause or provision shall be judicially construed and interpreted to be as
     similar in substance and content to such illegal,


                                                                              10

<PAGE>

     invalid or unenforceable clause or provision, as the context thereof would
     reasonably suggest, so as to thereafter be legal, valid and enforceable.

11.  NO RESERVATION. Submission of this Amendment for examination or signature
     is without prejudice and does not constitute a reservation, option or
     offer, and this Amendment shall not be effective until execution and
     delivery by all parties.

12.  COUNTERPARTS. This Amendment may be executed simultaneously in two or more
     counterparts, each of which shall be deemed an original, but all of which
     together shall constitute one and the same instrument.

              [The Remainder of this Page Intentionally Left Blank]


                                                                              11

<PAGE>

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment under
seal as of the date and year first above written.

                                      LANDLORD:

                                      BCIA NEW ENGLAND HOLDINGS LLC, a Delaware
                                      limited liability company

                                      By: BCIA NEW ENGLAND HOLDINGS MASTER LLC,
                                          a Delaware limited liability company,
                                          its Manager

                                      By: BCIA NEW ENGLAND HOLDINGS MANAGER LLC,
                                          a Delaware limited liability company,
                                          its Manager

                                      By: BCIA NEW ENGLAND HOLDINGS MANAGER
                                          CORP., a Delaware corporation,
                                          its Manager


                                      By: /s/ Karl W. Weller
                                          --------------------------------------
                                      Name: Karl W. Weller
                                      Title: EVP


                                      TENANT:

                                      PRI AUTOMATION, INC.,
                                      a Massachusetts corporation


                                      By: /s/ Cosmo S. Trapani
                                          --------------------------------------
                                      Name: Cosmo S. Trapani
                                      Title: VP & CFO


                                                                              12

<PAGE>

                                    EXHIBIT C

          Form of Subordination, Non-Disturbance and Attornment Agreement THIS
AGREEMENT is made and entered into as of the _____ day of _________, _____ by
and between THE CHASE MANHATTAN BANK, as Trustee under that certain Pooling and
Servicing Agreement dated as of November 1, 1999 for Certificateholders of the
Office Finance Corp Commercial Mortgage Pass-Through Certificates Series
1999-FL1 ("MORTGAGEE"), and Power-One, Inc., a Delaware corporation ("LESSEE").

                                    RECITALS:

     A. Mortgagee has made a loan (the "LOAN") to BCIA New England Holdings LLC,
a Delaware limited liability company ("BORROWER"), secured by the Borrower's
interest in the real property known and numbered 805 Middlesex Turnpike,
Billerica, Massachusetts, and more particularly described in EXHIBIT A attached
hereto and incorporated herein by reference (said real property and improvements
being herein called the "PROJECT"), such Loan being secured by a Mortgage,
Assignment of Leases and Rents, Security Agreement and Fixture Filing dated
_________________ (the "MORTGAGE"), and recorded with the _____________ Registry
of Deeds in Book ____, Page ___, which Mortgage constitutes a lien or
encumbrance on the Project; and

     B. Lessee is the holder of a leasehold estate in and to the Project (the
"DEMISED PREMISES"), under that Lease Agreement (the "LEASE") dated
_______________, 2000, executed by Borrower, as Landlord (Borrower being
sometimes hereinafter called "LESSOR"), and Lessee, as Tenant; and

     C. Lessee and Mortgagee desire to confirm their understandings with respect
to the Lease and the Mortgage.

                                   AGREEMENT:

     NOW, THEREFORE, in consideration of the foregoing and the mutual covenants
and agreements herein contained, Lessee and Mortgagee agree and covenant as
follows:

          1. NON-DISTURBANCE. Mortgagee agrees that it will not disturb the
possession of Lessee under the Lease upon any judicial or non-judicial
foreclosure of the Mortgage or upon acquiring title to the Project by
deed-in-lieu of foreclosure, or otherwise, if the Lease is in full force and
effect and Lessee is not then in default under the Lease, and that Mortgagee
will accept the attornment of Lessee thereafter so long as Lessee is not in
default under the Lease.

          2. ATTORNMENT. If the interests of Lessor in and to the Demised
Premises are owned by Mortgagee by reason of any deed-in-lieu of foreclosure,
judicial foreclosure, sale pursuant to any power of sale or other proceedings
brought by it or by any other manner, including, but not limited to, Mortgagee's
exercise of its rights under any assignment of leases and rents, and Mortgagee
succeeds to the interest of Lessor under the Lease, Lessee shall be bound to
Mortgagee under all of the terms, covenants and conditions of the Lease for the
balance of the term thereof remaining and any extension thereof duly exercised
by Lessee with the same


                                                                              13

<PAGE>

force and effect as if Mortgagee were the Lessor under the Lease; and Lessee
does hereby attorn to Mortgagee, as its lessor, said attornment to be effective
and self-operative, without the execution of any further instruments on the part
of any of the parties hereto, immediately upon Mortgagee's succeeding to the
interest of Lessor under the Lease; provided, however, that Lessee shall be
under no obligation to pay rent to Mortgagee until Lessee receives written
notice from Mortgagee that Mortgagee has succeeded to the interest of the Lessor
under the Lease or otherwise has the right to receive such rents. The respective
rights and obligations of Lessee and Mortgagee upon such attornment, to the
extent of the then remaining balance of the term of the Lease, shall be and are
the same as now set forth therein, it being the intention of the parties hereto
for this purpose to incorporate the Lease in this Agreement by reference, with
the same force and effect as if set forth in full herein.

          3. MORTGAGEE'S OBLIGATIONS. If Mortgagee shall succeed to the interest
of Lessor under the Lease, Mortgagee, subject to the last sentence of this
Paragraph 3, shall be bound to Lessee under all of the terms, covenants and
conditions of the Lease; provided, however, that Mortgagee shall not be:

               (a) Liable for any act or omission of any prior lessor (including
     Lessor); or

               (b) Subject to the offsets or defenses which Lessee might have
     against any prior lessor (including Lessor); or

               (c) Bound by any rent or additional rent or advance rent which
     Lessee might have paid for more than the current month to any prior lessor
     (including Lessor), and all such rent shall remain due and owing,
     notwithstanding such advance payment; or

               (d) Bound by any security or advance rental deposit made by
     Lessee which is not delivered or paid over to Mortgagee and with respect to
     which Lessee shall look solely to Lessor for refund or reimbursement;

               (e) Bound by any termination, amendment or modification of the
     Lease made without its consent and written approval;

               (f) Liable under any warranty of construction contained in the
     Lease or any implied warranty of construction; or

               (g) Liable for the performance or completion of any construction
     obligations under the Lease or for any loan or contribution or rent
     concession towards construction of the Demised Premises pursuant to the
     Lease.

Neither THE CHASE MANHATTAN BANK, as Trustee under that certain Pooling and
Servicing Agreement dated as of November 1, 1999 for Certificateholders of the
Office Finance Corp Commercial Mortgage Pass-Through Certificates Series
1999-FL1, nor any other party who from time to time shall be included in the
definition of Mortgagee hereunder, shall have any liability or responsibility
under or pursuant to the terms of this Agreement after it ceases to own an
interest in the Project. Nothing in this Agreement shall be construed to require
Mortgagee to see to the application of the proceeds of the Loan, and Lessee's
agreements set forth herein shall


                                                                              14

<PAGE>

not be impaired on account of any modification of the documents evidencing and
securing the Loan. Lessee acknowledges that Mortgagee is obligated only to
Borrower to make the Loan only upon the terms and subject to the conditions set
forth in the Loan Agreement between Mortgagee and Borrower pertaining to the
Loan. In no event shall Mortgagee or any purchaser of the Project at foreclosure
sale or any grantee of the Project named in a deed-in-lieu of foreclosure, nor
any heir, legal representative, successor, or assignee of Mortgagee or any such
purchaser or grantee (collectively the Mortgagee, such purchaser, grantee, heir,
legal representative, successor or assignee, the "SUBSEQUENT LANDLORD") have any
personal liability for the obligations of Lessor under the Lease and should the
Subsequent Landlord succeed to the interests of the Lessor under the Lease,
Tenant shall look only to the estate and property of any such Subsequent
Landlord in the Project for the satisfaction of Tenant's remedies for the
collection of a judgment (or other judicial process) requiring the payment of
money in the event of any default by any Subsequent Landlord as landlord under
the Lease, and no other property or assets of any Subsequent Landlord shall be
subject to levy, execution or other enforcement procedure for the satisfaction
of Tenant's remedies under or with respect to the Lease; provided, however, that
the Lessee may exercise any other right or remedy provided thereby or by law in
the event of any failure by Lessor to perform any such material obligation.

          4. SUBORDINATION. The Lease and all rights of Lessee thereunder are
subject and subordinate to the lien and the terms of the Mortgage and to any
deeds of trust, mortgages, ground leases or other instruments of security which
do now or may hereafter cover the Project or any interest of Lessor therein
(collectively, the "PRIOR ENCUMBRANCES") and to any and all advances made on the
security thereof and to any and all increases, renewals, modifications,
consolidations, replacements and extensions of the Mortgage or of any of the
Prior Encumbrances. This provision is acknowledged by Lessee to be
self-operative and no further instrument shall be required to effect such
subordination of the Lease. Lessee shall, however, upon demand at any time or
times execute, acknowledge and deliver to Mortgagee any and all instruments and
certificates that in Mortgagee's judgment may be necessary or proper to confirm
or evidence such subordination. If Lessee shall fail or neglect to execute,
acknowledge and deliver any such instrument or certificate, Mortgagee may, in
addition to any other remedies Mortgagee may have, as agent and attorney-in-fact
of Lessee, execute, acknowledge and deliver the same and Lessee hereby
irrevocably appoints Mortgagee as Lessee's agent and attorney-in-fact for such
purpose. However, notwithstanding the generality of the foregoing provisions of
this paragraph, Lessee agrees that Mortgagee shall have the right at any time to
subordinate the Mortgage, and any such other mortgagee or ground lessor shall
have the right at any time to subordinate any such Prior Encumbrances, to the
Lease on such terms and subject to such conditions as Mortgagee, or any such
other mortgagee or ground lessor, may deem appropriate in its discretion.

          5. NEW LEASE. Upon the written request of either Mortgagee or Lessee
to the other given at the time of any foreclosure, trustee's sale or conveyance
in lieu thereof, the parties agree to execute a lease of the Demised Premises
upon the same terms and conditions as the Lease between Lessor and Lessee, which
lease shall cover any unexpired term of the Lease existing prior to such
foreclosure, trustee's sale or conveyance in lieu of foreclosure.

          6. NOTICE. Lessee agrees to give written notice to Mortgagee of any
default by Lessor or Borrower under the Lease not less than thirty (30) days
prior to terminating the


                                                                              15

<PAGE>

Lease or exercising any other right or remedy thereunder or provided by law.
Lessee further agrees that it shall not terminate the Lease or exercise any such
right or remedy provided such default is cured within such thirty (30) days;
provided, however, that if such default cannot by its nature be cured within
thirty (30) days, then Lessee shall not terminate the Lease or exercise any such
right or remedy, provided the curing of such default is commenced within such
thirty (30) days and is diligently prosecuted thereafter. Such notices shall be
delivered by certified mail, return receipt requested to:

                    GE Capital Loan Services, Inc.
                    363 North Sam Houston Parkway East, Suite 1200
                    Houston, Texas 77060
                    Attention: Pat McEntee
                    and
                    General Electric Capital Corporation
                    Long Ridge Road
                    Stamford, Connecticut 06927
                    Attention: Vice President, Securitizations

          7. MORTGAGEE. The term "Mortgagee" shall be deemed to include THE
CHASE MANHATTAN BANK, as Trustee under that certain Pooling and Servicing
Agreement dated as of November 1, 1999 for Certificateholders of the Office
Finance Corp Commercial Mortgage Pass-Through Certificates Series 1999-FL1 and
any of its successors and assigns, including anyone who shall have succeeded to
Lessor's interest in and to the Lease and the Project by, through or under
judicial foreclosure or sale under any power or other proceedings brought
pursuant to the Mortgage, or deed in lieu of such foreclosure or proceedings, or
otherwise.

          8. ESTOPPEL. Lessee hereby certifies, represents and warrants to
Mortgagee that:

               (a) That the Lease is a valid lease and in full force and effect.
     That there is no existing default in any of the terms and conditions
     thereof and no event has occurred which, with the passing of time or giving
     of notice or both, would constitute an event of default;

               (b) That the Lease has not been amended, modified, supplemented,
     extended, renewed or assigned, and represents the entire agreement of the
     parties;

               (c) That, except as provided in the Lease, Lessee is entitled to
     no rent concessions or abatements;

               (d) That Lessee shall not pay rental under the Lease for more
     than one (1) month in advance. Lessee agrees that Lessee shall, upon
     written notice by Mortgagee, pay to Mortgagee, when due, all rental under
     the Lease;


                                                                              16

<PAGE>

               (e) That all obligations and conditions under the Lease to be
     performed to date have been satisfied, free of defenses and set-offs;

               (f) That Lessee has not received written notice of any claim,
     litigation or proceedings, pending or threatened, against or relating to
     Lessee, or with respect to the Demised Premises which would affect its
     performance under the Lease. Lessee has not received written notice of any
     violations of any federal, state, county or municipal statutes, laws,
     codes, ordinances, rules, regulations, orders, decrees or directives
     relating to the use or condition of the Demised Premises or Lessee's
     operations thereon.

          9. MODIFICATION AND SUCCESSORS. This Agreement may not be modified
orally or in any manner other than by an agreement, in writing, signed by the
parties hereto and their respective successors in interest. This Agreement shall
inure to the benefit of and be binding upon the parties hereto, their successors
and assigns.

          10. COUNTERPARTS. This Agreement may be executed in several
counterparts, and all so executed shall constitute one agreement, binding on all
parties hereto, notwithstanding that all parties are not signatories to the
original or the same counterpart.


                                                                              17

<PAGE>

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the day and year first above written.

MORTGAGEE:

                                        THE CHASE MANHATTAN BANK, as Trustee
                                        under that certain Pooling and Servicing
                                        Agreement dated as of November 1, 1999
                                        for Certificateholders of the Office
                                        Finance Corp Commercial Mortgage
                                        Pass-Through Certificates Series
                                        1999-FL1

                                        BY: GE CAPITAL LOAN SERVICES, INC., as
                                            Servicer pursuant to that certain
                                            Pooling and Servicing Agreement
                                            dated as of November 1, 1999 for
                                            Certificateholders of the Office
                                            Finance Corp Commercial Mortgage
                                            Pass-Through Certificates Series
                                            1999-FL1.


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


                                        LESSEE:


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


                                                                              18

<PAGE>

STATE OF
         ----------------------------
COUNTY OF
          ---------------------------

     This instrument was acknowledged before me on this ___________ day of
___________________, ______ by __________________________________, as
__________________________________ of GE CAPITAL LOAN SERVICES, INC., a Delaware
corporation, on behalf of said corporation.


(SEAL)                                  ----------------------------------------
                                        Notary Public in and for
                                        the State of
                                                     ---------------------------

                                        ----------------------------------------
                                        Print name of notary
                                        My Commission Expires:
                                                               -----------------

STATE OF
         ----------------------------
COUNTY OF
          ---------------------------

     This instrument was acknowledged before me on this __________ day of
_______, _____ by ______________________, as _________________________ of
_____________________, a _________________, on behalf of said _________________.


(SEAL)                                  ----------------------------------------
                                        Notary Public in and for
                                        the State of
                                                     ---------------------------

                                        ----------------------------------------
                                        Print name of notary
                                        My Commission Expires:
                                                               -----------------


                                                                              19