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F7/6/99
WTCEGAWL


                                                                Exhibit 10.1





                             WORLD TRADE CENTER EAST

                                    L E A S E



                                 by and between


                              EAST OFFICE OPERATING
                              LIMITED PARTNERSHIP,
                                   as Landlord


                                       and


                           BREAKAWAY SOLUTIONS, INC.,
                                    as Tenant



                                   dated as of
                                 October 7, 1999


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                             WORLD TRADE CENTER EAST

                                    L E A S E


                                TABLE OF CONTENTS

<TABLE>
<S>                                                                                                              <C>
ARTICLE 1 -- REFERENCE DATA

1.1      Subjects Referred To.....................................................................................1
1.2      Exhibits.................................................................................................5
1.3      Definitions .............................................................................................5

ARTICLE 2 -- PREMISES AND TERM

2.1      Premises................................................................................................10
2.2      Right of First Offer....................................................................................11
2.3      Term....................................................................................................11
2.4      Extension Option........................................................................................12

ARTICLE 3 -- IMPROVEMENTS

3.1      Construction of Building and Performance of Landlord's Work.............................................14
3.2      Substantial Completion..................................................................................15
3.3      Plans and Specifications................................................................................16
3.4      Tenant's Contractor.....................................................................................18
3.5      Funding of Allowance....................................................................................18
3.6      Mechanic's Liens........................................................................................19


ARTICLE 4 -- RENT

4.1      Fixed Rent..............................................................................................20
4.2      Additional Rent.........................................................................................20
         4.2.1    Real Estate Taxes..............................................................................20
         4.2.2    Personal Property Taxes........................................................................23
         4.2.3    Operating Costs................................................................................23
         4.2.4    Insurance......................................................................................26
         4.2.5    Utilities......................................................................................27
4.3      Late Payment of Rent....................................................................................28

</TABLE>

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<TABLE>
<S>                                                                                                              <C>
ARTICLE 5 -- LANDLORD'S COVENANTS

5.1      Affirmative Covenants...................................................................................28
         5.1.1    Heat and Air Conditioning......................................................................28
         5.1.2    Electricity....................................................................................29
         5.1.3    Cleaning; Water................................................................................29
         5.1.4    Elevator Service...............................................................................29
         5.1.5    Security.......................................................................................29
         5.1.6    Repairs........................................................................................29
         5.1.7    Shuttle Service................................................................................29
         5.1.8    Indemnification................................................................................29
5.2      Interruption............................................................................................30
5.3      Outside Services........................................................................................30

ARTICLE 6 -- TENANT'S ADDITIONAL COVENANTS

6.1      Affirmative Covenants...................................................................................30
         6.1.1    Perform Obligations............................................................................30
         6.1.2    Use............................................................................................31
         6.1.3    Repair and Maintenance.........................................................................31
         6.1.4    Compliance with Law............................................................................31
         6.1.5    Indemnification................................................................................31
         6.1.6    Landlord's Right to Enter......................................................................32
         6.1.7    Personal Property at Tenant's Risk.............................................................32
         6.1.8    Yield Up.......................................................................................32
         6.1.9 Rules and Regulations.............................................................................33
         6.1.10 Estoppel Certificate.............................................................................33
         6.1.11   Non-Discrimination and Affirmative Action .....................................................33

6.2      Negative Covenants......................................................................................34
         6.2.1    Assignment and Subletting......................................................................34
         6.2.2    Nuisance.......................................................................................37
         6.2.3    Hazardous Wastes and Materials.................................................................37
         6.2.4    Floor Load; Heavy Equipment....................................................................38
         6.2.5    Installation, Alterations or Additions.........................................................38
         6.2.6    Abandonment....................................................................................40
         6.2.7    Signs..........................................................................................40

ARTICLE 7 -- CASUALTY OR TAKING

7.1      Termination.............................................................................................40

7.2      Restoration.............................................................................................40
7.3      Award...................................................................................................41

</TABLE>

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<TABLE>
<S>                                                                                                              <C>
ARTICLE 8 -- DEFAULTS

8.1      Events of Default.......................................................................................41
8.2      Remedies................................................................................................42
8.3      Remedies Cumulative.....................................................................................43
8.4      Landlord's Right to Cure Defaults.......................................................................43
8.5      Effect of Waivers of Default............................................................................43
8.6      No Waiver, etc..........................................................................................44
8.7      No Accord and Satisfaction..............................................................................44

ARTICLE 9 -- RIGHTS OF RIGHTS OF MORTGAGEES AND GROUND LESSORS

9.1      Rights of Mortgagees and Ground Lessors ................................................................44
9.2      Modifications...........................................................................................45

ARTICLE 10 - APPRAISAL OF FAIR RENTAL VALUE

10.1     Dispute as to Fair Rental Value.........................................................................46
         10.1.1   Appointment of Appraisers......................................................................46
         10.1.2   Decision by Two Appraisers.....................................................................46
         10.1.3   Decision by Three Appraisers...................................................................47
10.2     Binding Effect; Costs...................................................................................47


ARTICLE 11 -- MISCELLANEOUS PROVISIONS

11.1     Notices From One Party to the Other.....................................................................47
11.2     Quiet Enjoyment.........................................................................................47
11.3     Lease Not to be Recorded................................................................................48
11.4     Limitation of Landlord's Liability......................................................................48
11.5     Acts of God.............................................................................................48
11.6     Landlord's Default......................................................................................48
11.7     Brokerage...............................................................................................49
11.8     Applicable Law and Construction.........................................................................49
11.9     Litigation Expenses.....................................................................................49
11.10    Roof Space..............................................................................................49


ARTICLE 12 - SECURITY DEPOSIT

12.1     Initial Security Deposit................................................................................52
12.2     Reduction Schedule......................................................................................52

</TABLE>

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<TABLE>
<S>                                                                                                              <C>
ARTICLE 13 - TENANT'S EMERGENCY GENERATOR

13.1     Tenant's Emergency Generator............................................................................53
13.2     Terms of Use............................................................................................53
13.3     Installation, Operation, Maintenance and Removal........................................................53
13.4     Access to Generator and Tank Areas......................................................................54

</TABLE>


EXHIBITS:

<TABLE>
         <S>                        <C>
         EXHIBIT A..................Legal Description
         EXHIBIT B..................Plan Showing the Premises
         EXHIBIT C..................Commencement Date Agreement
         EXHIBIT D..................Building Description
         EXHIBIT E..................Base Building Specifications
         EXHIBIT F..................Office Space Cleaning Specifications
         EXHIBIT G..................Rules and Regulations
         EXHIBIT H..................Tenant Estoppel Certificate
         EXHIBIT I..................Nondiscrimination and Affirmative Action Covenants
         EXHIBIT J..................Rentable Area Definition and Measurement Method
         EXHIBIT K..................Landlord'sWiring Instructions

</TABLE>


<PAGE>


                                    ARTICLE 1

                                 REFERENCE DATA


1.1      SUBJECT REFERRED TO.

         Each reference in this Lease to any of the following subjects shall be
         construed to incorporate the data stated for that subject in this
         Section 1.1.

<TABLE>
         <S>                                <C>
         Date of this Lease:                October    , 1999
                                                   ----

         Building:                          The 16 story building in the City of
                                            Boston being constructed on a parcel
                                            of land described in Exhibit A
                                            attached hereto and known as World
                                            Trade Center East, Two Seaport Lane
                                            (the Building and such parcel of
                                            land hereinafter being collectively
                                            referred to as the "Property").
                                            Specifically excluded from the
                                            Building is the Garage.

         Landlord:                          East Office Operating
                                            Limited Partnership

         Original Notice
         Address of Landlord:               Suite 75
                                            World Trade Center Boston
                                            Boston, MA  02210

                                            With a copy to:

                                            General Counsel
                                            FMR Corp.
                                            82 Devonshire Street
                                            Boston, MA 02109

         Tenant:                            Breakaway Solutions, Inc.
                                            (a Delaware corporation)

         Original Notice
         Address of Tenant:                 50 Rowes Wharf
                                            Boston, Massachusetts  02110

         Premises:                          The aggregate of (1) the Initial
                                            Space and the Additional Space
                                            commencing as of the Commencement
                                            Date therefor and (2) the Expansion
                                            Space commencing on the Commencement
                                            Date therefor.

</TABLE>


                                       1
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<TABLE>
         <S>                                <C>
         Initial Space and
         Additional Space:                  The entire 8th Floor, the entire 7th
                                            Floor of the Building and a portion
                                            of the 6th Floor of the Building,
                                            substantially as shown on Exhibit B
                                            attached hereto.

         Initial Space:                     An undesignated portion of the
                                            Initial Space and Additional Space
                                            containing approximately 60,000
                                            square feet of Rentable Area.

         Additional Space:                  An undesignated portion of the
                                            Initial Space and Additional Space
                                            containing approximately 10,179
                                            square feet of Rentable Area.

         Expansion Space:                   A portion of the 6th Floor of the
                                            Building, substantially as shown on
                                            Exhibit B attached hereto.

         Rentable Area
         of the Premises:                   Initial Space: approximately 60,000
                                                           square feet of
                                                           Rentable Area;

                                            Additional Space:  approximately
                                                           10,179 square feet of
                                                           Rentable Area; and

                                            Expansion Space:  approximately
                                                           9,891 square feet of
                                                           of Rentable Area.
                                                           --------------------

                                            Total Premises:  approximately
                                                             80,070 square feet
                                                             of Rentable Area.


         Rentable Area
         of  the Building:                  Approximately 503,989 square feet.

         Office Area:                       All areas of the Building designated
                                            by Landlord from time to time for
                                            leasing for office use.

         Rentable Area of
         The Office Area:                   Approximately 490,882 square feet.

         Original Term:                     The period commencing on the
                                            Commencement Date for the Initial
                                            Space and ending on the last day of
                                            the 7th Lease Year.

         Commencement Dates:                The Commencement Date for the
                                            Initial Space and the Additional
                                            Space shall be the Substantial
                                            Completion Date for the Initial
                                            Space and the Additional Space.

                                            The Commencement Date for the
                                            Expansion Space shall be the later
                                            of (a) the Substantial Completion
                                            Date for the Expansion Space or (b)
                                            July 15, 2001.

</TABLE>

                                       2
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<TABLE>
        <S>                                <C>
         Extension Option:                  Tenant has the right to extend the
                                            Original Term for 1 additional
                                            period of 5 years in accordance with
                                            and subject to Section 2.4 hereof.

         Scheduled Delivery Dates:          The Scheduled Delivery Date for the
                                            Initial Space and the Additional
                                            Space shall be August 7, 2000.

                                            The Scheduled Delivery Date for the
                                            Expansion Space shall be July 15,
                                            2001.


         Allowance:                         $3,158,055 for the Initial Space and
                                            the Additional Space, and $445,095
                                            for the Expansion Space, totaling
                                            $3,603,150 for the entire Premises.

         Annual Fixed Rent Rate and
         Monthly Fixed Rent Rate:

</TABLE>


         The following rates shall apply for the Initial Space and the
Additional Space:

<TABLE>
                  Fixed Rent Period                 Annual Fixed Rent Rate          Monthly Fixed Rent Rate
                  -----------------                 ----------------------          -----------------------
                         <S>                             <C>                             <C>

                         1st                             $2,610,000.00                   $217,500.00
                         2nd                             $3,052,786.50                   $254,398.88
                         3rd                             $3,105,420.75                   $258,785.06
                         4th                             $3,333,502.50                   $277,791.88

</TABLE>


         In addition to the above, the following rates shall apply for the
         Expansion Space from and after the Fixed Rent Commencement Date
         therefor (which is scheduled to occur during the 2nd Fixed Rent Period
         at the beginning of the 2nd Lease Year):

<TABLE>
<CAPTION>
                  Fixed Rent Period                 Annual Fixed Rent Rate          Monthly Fixed Rent Rate
                  -----------------                 ----------------------          -----------------------
                         <S>                              <C>                             <C>

                         2nd                              $430,258.50                     $35,854.88
                         3rd                              $437,676.75                     $36,473.06
                         4th                              $469,822.50                     $39,151.88

</TABLE>

<TABLE>
<S>                                 <C>
1st Fixed Rent Period:              The period from the Fixed Rent Commencement
                                    Date for the Initial Space through the day
                                    before the Fixed Rent Commencement Date for
                                    the Additional Space.

2nd Fixed Rent Period:              The period from the Fixed Rent Commencement
                                    Date for the Additional Space through the
                                    end of the 2nd Lease Year.

</TABLE>


                                       3
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<TABLE>
<S>                                 <C>
3rd Fixed Rent Period:              The period from the beginning of the 3rd
                                    Lease Year through the end of the 4th Lease
                                    Year.

4th Fixed Rent Period:              The period from the beginning of the 5th
                                    Lease Year through the end of the 7th Lease
                                    Year.

Fixed Rent
Commencement Dates:                 The Fixed Rent Commencement Date for the
                                    Initial Space shall be the date 100 days
                                    after the Commencement Date for the Initial
                                    Space and the Additional Space.

                                    The Fixed Rent Commencement Date for the
                                    Additional Space shall be the date 281 days
                                    after the Commencement Date for the Initial
                                    Space and the Additional Space.

                                    The Fixed Rent Commencement Date for the
                                    Expansion Space shall be the date 120 days
                                    after the Commencement Date for the
                                    Expansion Space.

Base Operating Costs:               An amount equal to the greater of (a) $7.50
                                    times the Rentable Area of the Office Area
                                    (i.e., $3,681,615.00) based upon the
                                    currently anticipated Rentable Area of the
                                    Office Area), or (b) the actual amount of
                                    Operating Costs incurred during calendar
                                    year 2001.

Base Taxes:                         An amount equal to $3.18 times the total
                                    Rentable Area of the Building (i.e.,
                                    $1,602,685.02 based upon the currently
                                    anticipated total Rentable Area of the
                                    Building).

Tenant's Tax Percentage:            The ratio of the Rentable Area of the
                                    Premises to the total Rentable Area of the
                                    Building, which shall be deemed to be as
                                    follows:

                                    Initial Space:   11.91%
                                    Additional Space: 2.02%
                                    Expansion Space:  1.96%
                                    -----------------------
                                    Total Premises:  15.89%

</TABLE>


                                       4
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<TABLE>
<S>                                 <C>
Tenant's                            Office Percentage: The ratio of the
                                    Rentable Area of the Premises to the total
                                    Rentable Area of the Office Area, which
                                    shall initially be deemed to be as follows:

                                    Initial Space:   12.22%
                                    Additional Space: 2.07%
                                    Expansion Space:  2.02%
                                    -----------------------
                                    Total Premises:  16.31%

Permitted Uses:                     General business offices.

Commercial General
Liability Insurance Limits:         $3,000,000 per occurrence
                                    $5,000,000 general aggregate.

Broker:                             Spaulding & Slye and Cresa Partners

Security Deposit Amount:            $2,000,000.00

</TABLE>

1.2      EXHIBITS

         The Exhibits listed in the Table of Contents and attached hereto are
         incorporated in this Lease by reference and are to be construed as a
         part of this Lease.

1.3      DEFINITIONS

         For the purposes of this Lease, the following terms shall be as defined
         below or as defined in the Section of this Lease referenced below:

         "ABATEMENT THRESHOLD" shall be as defined in Section 4.2.5.

         "ADA" shall mean the Americans With Disabilities Act of 1990 and all
         rules and regulations promulgated thereunder.

         "AIR CONDITIONING DESIGN CONDITIONS" shall be as defined in Section
         5.1.1(a).

         "ALLOWANCE" shall be as defined in Section 1.1.

         "ANNUAL FIXED RENT RATE" shall be as defined in Section 1.1.

         "ARCHITECT" shall be as defined in Section 3.3.

         "BASE BUILDING WORK" shall be as defined in Section 3.1.

         "BASE OPERATING COSTS" shall be as defined in Section 1.1.

                                       5
<PAGE>

         "BASE TAXES" shall be as defined in Section 1.1.

         "BROKER" shall be the broker or brokers listed in Section 1.1.

         "BUILDING" shall be as defined in Section 1.1.

          "BUILDING HOLIDAYS" shall mean New Year's Day, Martin Luther King's
          Day, Presidents' Day, Memorial Day, Independence Day, Labor Day,
          Thanksgiving Day and the Friday thereafter, and Christmas Day, or such
          weekday as may be generally observed when any such holiday occurs on a
          weekend.

         "CAPITAL EXPENDITURES" shall be as defined in Section 4.2.3(d).

         "CHANGE ORDER COSTS"  shall be as defined in Section 3.6.

         "COMMENCEMENT DATE" shall be as defined in Section 2.2.

         "COMMUNICATIONS EQUIPMENT" shall be as defined in Section 11.10(a).

         "CONSTRUCTION DOCUMENTS" shall be as defined in Section 3.3(a).

         "DEFAULT RATE" shall mean a fluctuating rate per annum equal to the
         lesser of (a) 4% above the Prime Rate, or (b) the maximum legally
         permitted rate.

         "DOCUMENTS" shall be as defined in Section 3.3(a).

         "ENVIRONMENTAL LAWS" "shall be as defined in Section 6.2.3.

         "EXTENSION TERM" shall be as defined in Section 2.3(a).

         "EXPANSION SPACE" shall be as defined in Section 1.1.

         "FAA" shall be as defined in Section 11.10(f).

         "FAIR RENTAL VALUE" shall be as defined in Section 2.4(c).

         "FCC" shall be as defined in Section 11.10(f).

         "1ST FIXED RENT PERIOD" shall be as defined in Section 1.1.

         "FIXED RENT COMMENCEMENT DATE" shall be as defined in Section 1.1.

         "FIXED RENT PERIOD" shall mean each of the 1st Fixed Rent Period, 2nd
         Fixed Rent Period, 3rd Fixed Rent Period and 4th Fixed Rent Period.

                                       6
<PAGE>

         "4TH FIXED RENT PERIOD" shall be as defined in Section 1.1.

         "GARAGE" shall mean the underground parking garage serving the Building
         and the complex of which the Building will be a part.

         "GENERATOR" shall be as defined in Section 13.1.

         "HAZARDOUS MATERIALS" shall be as defined in Section 6.2.3.

         "HAZARDOUS MATERIALS ACTIVITIES" shall be as defined in Section 6.2.3.

         "INITIAL SPACE" shall be as defined in Section 1.1.

         "LANDLORD" shall be as defined in Sections 1.1 and 11.4.

         "LANDLORD AFFILIATE" shall mean any entity controlled by, controlling
         or under common control with Landlord.

         "LANDLORD'S ENGINEERS" shall be as defined in Section 3.3(a).

         "LANDLORD PLAN NOTICE" shall be as defined in Section 3.3(b).

         "LANDLORD'S RESTORATION WORK"  shall be as defined in Section 7.2.

         "LANDLORD'S WORK" shall be as defined in Section 3.1.

         "LEASE YEAR" shall mean any 12 month period beginning on the Fixed Rent
         Commencement Date for the Initial Space or on any anniversary of the
         Fixed Rent Commencement Date for the Initial Space, except that the
         last Lease Year shall end on the expiration or earlier termination of
         the term.

         "MASSPORT" shall be as defined in Section 9.1(a).

         "MASSPORT LEASE" shall be as defined in Section 9.1(a).

         "MEASUREMENT METHOD" shall be as defined in Exhibit J.

         "MONTHLY FIXED RENT RATE" shall be as defined in Section 1.1.

         "NON-DISTURBANCE AGREEMENT" shall be as defined in Section 9.1(a).

         "NORMAL BUSINESS HOURS" shall mean from 8:00 a.m. to 6:00 p.m. Monday
         through Friday and from 9:00 a.m. to 1:00 p.m. on Saturdays, except on
         Building Holidays.

                                       7
<PAGE>


         "NORMAL OFFICE CHEMICALS" shall be as defined in Section 6.2.2.

         "OFFICE AREA" shall be as defined in Section 1.1.

         "121A OWNER" shall be as defined in Section 4.2.1(f).

         "OPERATING COSTS" shall be as defined in Section 4.2.3(b).

         "ORIGINAL NOTICE ADDRESS OF LANDLORD" shall be as defined in Section
         1.1.

         "ORIGINAL NOTICE ADDRESS OF TENANT" shall be as defined in Section 1.1.

         "ORIGINAL TERM" shall be as defined in Section 1.1.

         "OUTSIDE SERVICES" shall be as defined in Section 5.3.

         "PART OF THE PREMISES" shall mean each of the Initial Space, the
         Additional Space and the Expansion Space.

         "PERMITTED TRANSFER"  shall be as defined in Section 6.2.1(f).

         "PERMITTED USES" shall be as defined in Section 1.1.

         "PREMISES" shall be as defined in Section 1.1

          "PRIME RATE" shall mean the prime rate published (or the highest
          published prime rate if more than one is published) by the Wall Street
          Journal (or if such publication ceases, a comparable substitute
          reasonably designated by Landlord).

         "PROPERTY" shall be as defined in Section 1.1.

         "RENTABLE AREA" shall be as defined in Exhibit J.

         "RENTABLE AREA OF THE PREMISES" shall be as defined in Section 1.1.

          "RETAIL AREA" shall mean all areas of the Building designated by
          Landlord from time to time for leasing for retail use.

         "ROOF SPACE" shall be as defined in Section 11.10(a).

         "SCHEDULED DELIVERY DATE" shall be as defined in Section 1.1.

         "SECURITY DEPOSIT" shall be as defined in Section 12.1.

                                       8
<PAGE>


         "SECURITY DEPOSIT AMOUNT" shall be as defined in Section 1.1, as the
         same may be reduced in accordance with and subject to Section 12.02.

         "6A CONTRACT" shall be as defined in Section 4.2.1(f).

         "6A PAYMENT" shall be as defined in Section 4.2.1(e).

         "2ND FIXED RENT PERIOD" shall be as defined in Section 1.1.

         "STAIRWAY" shall be as defined in Section 3.3(f).

         "SUBSTANTIALLY COMPLETED" shall be as defined in Section 3.2.

         "SUBSTANTIAL COMPLETION DATE FOR THE INITIAL SPACE AND THE ADDITIONAL
         SPACE" shall be as defined in Section 3.2(a).

         "SUBSTANTIAL COMPLETION DATE FOR THE EXPANSION SPACE" shall be as
         defined in Section 3.2(a).

         "SUCCESSOR LANDLORD" shall be as defined in Section 9.1(b)

         "SUPERIOR LEASE" shall be as defined in Section 9.1(a).

         "SUPERIOR LESSOR" shall be as defined in Section 9.1(a).

         "SUPERIOR MORTGAGE" shall be as defined in Section 9.1(a).

         "SUPERIOR MORTGAGEE" shall be as defined in Section 9.1(a).

         "TANK" shall be as defined in Section 13.1.

         "TAXES" shall be as defined in Section 4.2.1(d).

         "TAX OBLIGATION" shall be as defined in Section 4.2.1.

         "TAX YEAR" shall mean any calendar year all or part of which occurs
         during the term.

         "TENANT" shall be as defined in Section 1.1.

         "TENANT AFFILIATE" shall be as defined in Section 6.2.1(f)(1).

         "TENANT DELAY" shall be as defined in Section 3.2(b).

         "TENANT'S MARKET VALUE OF EQUITY" shall be as defined in Section
         6.2.1(e).

                                       9

<PAGE>

         "TENANT'S OFFICE PERCENTAGE" shall be as defined in Section 1.1.

         "TENANT'S SHARE OF OPERATING COSTS" shall be as defined in Section
         4.2.3(a).

         "TENANT'S SHARE OF TAXES" shall be as defined in Section 4.2.1(a).

         "TENANT SUCCESSOR"  shall be as defined in Section 6.2.1(f)(2).

         "TENANT'S TAX PERCENTAGE" shall be as defined in Section 1.1.

         "TERM" shall be as defined in Section 2.3(a).

         "TERMINATION DEADLINE" shall be as defined in Section 3.1(c).

         "3RD FIXED RENT PERIOD" shall be as defined in Section 1.1.

         "TIW" shall be as defined in Section 3.1.

                                    ARTICLE 2

                                PREMISES AND TERM

2.1      PREMISES. (a) Landlord hereby leases to Tenant and Tenant hereby leases
         from Landlord, subject to and with the benefit of the terms, covenants,
         conditions and provisions of this Lease, the Premises, excluding the
         roof, exterior faces of exterior walls, the common stairways,
         stairwells, elevators and elevator shafts, and pipes, ducts, conduits,
         wires, and appurtenant fixtures serving exclusively or in common other
         parts of the Building, and if the Premises includes less than entire
         rentable area of any floor, excluding the central core area of such
         floor.

         (b) Tenant shall have, as appurtenant to the Premises, rights to use in
         common, subject to reasonable rules of general applicability to tenants
         of the Building from time to time made by Landlord of which Tenant is
         given notice: (1) the common lobbies, hallways, stairways, and
         elevators of the Building, (2) common walkways necessary for access to
         the Building, and (3) if the Premises include less than the entire
         rentable area of any floor, the common toilets and other common
         facilities in the central core area of such floor.

         (c) Landlord shall make available to the Tenant during the term of this
         lease up to 70 parking spaces in the Garage, on an unassigned basis and
         subject to the reasonable rules and regulations from time to time in
         force. Tenant shall pay for such spaces monthly at the prevailing rate
         in effect from time to time. Tenant shall notify Landlord on or before
         the Commencement Date for the Initial Space and the Additional Space
         how many of

                                       10
<PAGE>

         such parking spaces Tenant desires to use and the amount so elected
         shall remain fixed for the term of this Lease.

         (d) Landlord reserves the right from time to time, upon reasonable
         notice (except in the case of emergency) and without unreasonable
         interference with Tenant's use of the Premises: (1) to install, use,
         maintain, repair, replace and relocate for service to the Premises
         and/or other parts of the Building, pipes, ducts, conduits, wires and
         appurtenant fixtures, wherever located in the Premises or Building, (2)
         to alter or relocate any other common facility, (3) to make any repairs
         and replacements to the Premises which Landlord may reasonably deem
         necessary, and (4) in connection with any excavation made upon adjacent
         land of Landlord or others, to enter, and to license others to enter,
         upon the Premises to do such work as the person causing such excavation
         deems necessary to preserve the wall of the Building from injury or
         damage and to support the same.

2.2      RIGHT OF FIRST OFFER. If any space on the 6th floor of the Building
         that is not subject to any rights of the first tenant thereof or the
         first expansion rights granted by Landlord to another tenant with
         regard to such space nor previously occupied by nor previously offered
         to Tenant pursuant to this Section 2.2 becomes available during the
         Original Term of this Lease, prior to marketing such space, other than
         to the then tenant thereof, Landlord shall first offer to Tenant the
         opportunity to lease such space, provided that (a) the initial Tenant
         named herein (and/or the transferee in a Permitted Transfer) occupies
         at least 70% of the Premises, and (b) Tenant is not in default
         hereunder beyond any applicable grace period at such time. The rent,
         length of term and other terms and conditions offered to Tenant shall
         be the same as Landlord would then offer for such to the general
         market, including market tenant improvements (if any), leasing
         commissions, rents and other terms on which Landlord would offer
         comparable space in the Building. Such offer may be for a term that is
         not coterminous with the term hereof. Tenant shall have 10 business
         days to accept or reject such offer with respect to the entirety of
         such space. If Tenant accepts such offer, Landlord and Tenant shall
         both negotiate in good faith an amendment to this Lease with respect to
         such space, acceptable to both parties. If Tenant rejects such offer,
         or fails to accept such offer in writing to Landlord within such 10
         business day period, Landlord will then be free to offer such space to
         the general market, but Landlord may not lease such space at a net
         effective rent (taking into account any tenant improvements, free rent
         or other concessions) which is less than 90% of that offered to Tenant
         without again offering such space to Tenant at such lesser rent in
         accordance herewith.

2.3      TERM. The Original Term shall begin with regard to each of the Initial
         Space, Additional Space and Expansion Space on the respective
         Commencement Date therefor and shall continue for the Original Term,
         unless sooner terminated as hereinafter provided. When the dates of the
         beginning and end of the term have been determined for each of the
         Initial Space, Additional Space and Expansion Space, such dates shall
         be evidenced by a document, in the form attached hereto as Exhibit C,
         executed by Landlord and Tenant and delivered each to the other.
                                       11

<PAGE>

2.4      EXTENSION OPTION. (a) Provided that as of the date of the notice
         specified below and at the commencement of the Extension Term, as
         defined below, Tenant is not in default beyond any applicable grace
         period and has not previously been in default of its obligations under
         this Lease beyond any applicable grace period during the immediately
         preceding 12 months and that Tenant has not assigned this Lease or
         sublet more than 30% of the Premises (excluding Permitted Transfers),
         Tenant shall have the right to extend the term of this Lease for 1
         additional period of 5 years, such period to begin immediately upon the
         expiration of the then current term of this Lease (the "Extension
         Term"). All of the terms, covenants and provisions of this Lease shall
         apply to such Extension Term except that the Annual Fixed Rent Rate for
         such Extension Term shall be the Fair Rental Value of the Premises at
         the commencement of such Extension Term, as designated by Landlord. If
         Tenant shall elect to exercise any of the aforesaid options, it shall
         do so by giving Landlord notice in writing of its intention to do so
         not later than 15 months prior to the expiration of the then current
         term of this Lease. It is agreed that time is of the essence of this
         Section 2.3. Accordingly, if Tenant fails timely to exercise its option
         for any Extension Term on or before the applicable exercise date
         specified above, Tenant shall have no further right or option to extend
         the term of this Lease hereunder or otherwise. The Original Term and
         the Extension Term are herein together called the "term."

         (b) If Tenant timely and properly gives such notice with regard to the
         Extension Term, the term of this Lease shall be automatically extended
         for the Extension Term without the execution of any additional
         documents.

         (c)      (1) For the purposes hereof, the "Fair Rental Value" of the
                  Premises shall mean the fair rental value thereof that that
                  would be agreed upon between a landlord and a tenant executing
                  a lease with respect to comparable space in a comparable
                  building located in Boston, Massachusetts for a comparable
                  term, upon all of the other business terms of this Lease
                  assuming the following:

                  (A) the landlord and tenant are well informed and well advised
                  and each is acting in what it considers to be its own best
                  interests;

                  (B) the rental shall reflect the condition of the Premises and
                  all residual value of any improvements to the Premises; and

                  (C) the transaction takes into consideration the additional
                  rent to be paid by Tenant and all applicable brokerage
                  commissions.

                  (2) In no event, however, shall the Fair Rental Value be less
                  than the Annual Fixed Rent Rate in effect immediately prior to
                  the Extension Term.

                  (3) Notwithstanding anything to the contrary herein contained,
                  the parties hereby agree that in connection with any
                  determination of Fair Rental Value hereunder, Landlord shall
                  have the right, exercisable by written notice to Tenant
                                       12

<PAGE>

                  on or before the time that Landlord gives Tenant its
                  designation of Fair Rental Value hereunder :

                  (A)      to change Base Operating Costs from the amount stated
                           in Section 1.1 to an amount equal to the actual
                           amount of Operating Costs for the immediately
                           preceding Lease Year; and/or

                  (B)      to change the Base Taxes from the amount stated in
                           Section 1.1 to an amount equal to the actual amount
                           of the 6A Payment or Taxes for the immediately
                           preceding fiscal/tax year for which Landlord has
                           actual data.

                  If Landlord exercises such right, such new base amounts shall
                  then apply for the Extension Term and shall be taken into
                  account in determining the Fair Rental Value.

         (d) If Tenant disagrees with Landlord's designation of the Fair Rental
         Value, and the parties cannot agree thereon, then the Fair Rental Value
         shall be determined by the appraisal process set forth in Article 10
         hereof.

         (e) If Tenant exercises its right of appraisal and the appraisal has
         not been concluded at the commencement of the Extension Term, Tenant
         shall pay annual Fixed Rent as so determined by Landlord and additional
         rent as provided in Section 4.2 hereof. If the Fair Rental Value as
         determined by appraisal is greater than or less than Fair Rental Value
         as determined by Landlord, then any adjustment required to correct the
         amount previously paid shall be made by payment by the appropriate
         party 10 days after such determination of Fair Rental Value.

         (f) Notwithstanding any contrary provision of this Section 2.4 or any
         other provision of this Lease, any purported exercise by Tenant of its
         rights hereunder shall be void and of no effect unless on the date of
         Tenant's notice to Landlord exercising its right to extend the term for
         the Extension Term and on the date of commencement of the Extension
         Term: (i) this Lease is in full force and effect; (ii) Tenant is not in
         default of any of its obligations under this Lease beyond any
         applicable grace period; and (iii) the original Tenant hereunder
         (and/or the transferee in a Permitted Transfer) continues in occupancy
         of at least 70% of the Premises; provided, however, that Landlord
         reserves the right to waive by written notice the provisions of this
         paragraph with respect to any Extension Term.

         (g) In the event Tenant elects to exercise the extension option as set
         forth in this Section 2.4, Landlord and Tenant agree to enter into an
         amendment to this Lease to confirm such exercise and to document all
         changes to this Lease resulting from any exercise of such option;
         provided, however, the execution of any such amendment shall not be a
         condition precedent to the valid exercise by Tenant of the extension
         option granted herein.

                                       13

<PAGE>



                                    ARTICLE 3

                                  IMPROVEMENTS

3.1      CONSTRUCTION OF BUILDING AND PERFORMANCE OF LANDLORD'S WORK. (a) The
         Building will be constructed substantially in accordance with Exhibit
         D, the Building Description. Landlord shall cause to be performed the
         work required by Exhibit D and Exhibit E, Base Building Specifications
         (collectively, referred to as the "Base Building Work" or "Landlord's
         Work"). The parties acknowledge and agree that Landlord's Work in the
         Premises will be performed in two phases, the first being Landlord's
         Work in the Initial Space and the Additional Space and the second being
         Landlord's Work in the Expansion Space, and that the provisions of this
         Article 3 shall apply to each of such phases separately except as
         otherwise expressly provided or implied by the context. All work other
         than Landlord's Work that is necessary or desirable to prepare the
         Premises for Tenant's occupancy shall be performed by Tenant in
         accordance with and subject to the requirements of this Lease (such
         work being referred to herein as the "TIW"). All such Landlord's Work
         shall be done in a good and workmanlike manner employing new first
         quality materials and in compliance with all applicable zoning,
         building, fire, health and other codes, regulations, ordinances and
         laws. Without limiting the foregoing, Landlord agrees that Landlord's
         Work (including construction of the common areas and all Base Building
         Work within each part of the Premises) shall be performed in compliance
         with the ADA. Landlord shall have the right, for the purpose of
         reducing costs or insuring availability, to substitute materials of at
         least equal kind and quality for those specified in Exhibit E. Subject
         to the provisions of Section 11.5 hereof and to delay caused by Tenant
         Delay, Landlord shall use diligence (1) to cause Landlord's Work in the
         Initial Space and the Additional Space to be substantially completed by
         the Scheduled Delivery Date therefor, and (2) to cause Landlord's Work
         in the Expansion Space to be performed on or before the Scheduled
         Delivery Date therefor; provided, however that Landlord shall have no
         responsibility or liability for failing to do so except to the extent
         otherwise expressly provided in Sections 3.1(b) and 3.1(c) below.

         (b) Notwithstanding Section 3.1(a) above, if the Substantial Completion
         Date for the Initial Space and the Additional Space has not occurred on
         or before the Scheduled Delivery Date therefor, which date shall be
         extended for any delays in the performance of Landlord's Work caused by
         Tenant Delay or causes beyond Landlord' reasonable control, then Tenant
         shall be entitled to a credit against the Fixed Rent and Additional
         Rent first payable after the Fixed Rent Commencement Date for the
         Initial Space and the Additional Space in the amount of 1 day's Fixed
         Rent for the Initial Space for each day of such delay until the
         Substantial Completion Date for the Initial Space and the Additional
         Space occurs.

         (c) Notwithstanding Section 3.1(a) above, if the Commencement Date has
         not occurred on or before December 31, 2000, which date shall be
         extended for any delays caused by Tenant Delay (as so extended the
         "Termination Deadline"), Tenant may terminate this Lease by giving
         Landlord written notice of its election to do so on or

                                       14

<PAGE>

         before the earlier of the Commencement Date or 1 month after the
         Termination Deadline. In such event, if Tenant timely gives such
         notice, this Lease shall terminate unless the Commencement Date occurs
         within 30 days thereafter, in which case this Lease shall continue in
         full force and effect and Tenant's termination notice shall be void. If
         Tenant fails timely to give such notice, Tenant shall have no further
         right to terminate this Lease under this Section 3.1(c), time being of
         the essence hereof.

3.2      SUBSTANTIAL COMPLETION. (a) The term "substantially completed" as used
         herein with regard to any part of the Premises shall mean that (1)
         Landlord's architect has certified that Landlord's Work therein has
         been completed, with the exception of minor items which can be fully
         completed without material interference with Tenant and other items
         which because of the seasonal nature of the item (such as HVAC
         balancing) are not practicable to do at the time, and (2) a certificate
         of occupancy has been issued for so much of the Base Building Work as
         is necessary to obtain a certificate of occupancy for the Premises,
         which may be issued on a temporary basis so long as Tenant may occupy
         the Premises for the performance of the TIW and any requirements for
         obtaining a permanent certificate of occupancy may be satisfied by
         Landlord without material interference with the performance of the TIW.
         If Landlord's Work in any part of the Premises is delayed due to Tenant
         Delay, then, for the purposes of determining the Commencement Date
         therefor, the Landlord's Work shall be deemed to be substantially
         completed on the date that such work would have been substantially
         completed but for such Tenant Delay. If the Landlord's Work is deemed
         substantially completed, pursuant to the foregoing (and the term shall
         have commenced by reason thereof), but the Landlord's Work is not in
         fact substantially completed, Tenant shall not (except with Landlord's
         consent) be entitled to take possession of the Premises for any purpose
         until the Landlord's Work is in fact substantially completed. Any of
         Landlord's Work not fully completed on the date when Landlord's work is
         in fact substantially completed shall thereafter be so completed within
         60 days thereafter by Landlord. The date when Landlord's Work in the
         Initial Space and the Additional Space has been (or is deemed to have
         been) substantially completed in accordance herewith is referred to
         herein as the "Substantial Completion Date for the Initial Space and
         the Additional Space." The date when Landlord's Work in the Expansion
         Space has been (or is deemed to have been) substantially completed in
         accordance herewith is referred to herein as the "Substantial
         Completion Date for the Expansion Space."

         (b) For the purposes hereof "Tenant Delay" shall be defined as any
         delay in the performance of Landlord's Work caused in fact by (i)
         special work, long lead-time items, changes, alterations or additions
         to Landlord's Work requested by Tenant and agreed to by Landlord (in
         its sole discretion), (ii) delay and/or default on the part of Tenant
         or its contractors including, without limitation, the utility companies
         or other entities furnishing communications, data processing or other
         service or equipment to Tenant who may have been granted access to the
         Premises by Landlord prior to the Commencement Date, (iv) any
         interference with the performance of Landlord's Work by Tenant,
         Tenant's Architect or any of its agents, employees, engineers or
         contractors, or (v) any other action or inaction by Tenant or any of
         its agents, employees or contractors.

                                       15

<PAGE>


         (c) On or about the date when Landlord's Work is in fact substantially
         completed, Landlord's Project Manager and Tenant's Architect shall
         conduct a joint walkthough of the Premises and Tenant's Architect shall
         prepare a mutually acceptable punchlist setting forth any items of
         Landlord's Work which are uncompleted or do not conform to Exhibit E
         based on such walkthrough, and deliver the same to Landlord's Project
         Manager, and Landlord's Project Manager shall give Tenant's Architect
         its final comments thereon within 10 business days after receipt
         thereof. Any dispute concerning the items to be included on such
         punchlist shall be resolved by Landlord's architect for the Building,
         subject to Tenant's right to dispute the same by written notice to
         Landlord within 10 business days of after receipt of notice thereof.
         Landlord's Work shall be deemed approved by Tenant when Tenant occupies
         the Premises for the performance of the TIW, except for items on such
         punchlist, and any defects in materials or workmanship or seasonal
         adjustments not reasonably observable on the Commencement Date of which
         Tenant shall give Landlord written notice within 1 year after the
         Commencement Date (or as to any punchlist items, 1 year after their
         completion).

3.3      PLANS AND SPECIFICATIONS. (a) Tenant agrees to prepare, at Tenant's
         sole cost and expense, and furnish to Landlord, architectural,
         mechanical, electrical, plumbing, fire protection and structural
         engineering schematic design documents, design development documents
         and final construction documents for the TIW (such documentation and
         the constituent items thereof are referred to herein collectively and
         respectively as the "Documents"; and the final construction documents
         approved by Landlord hereunder are referred to herein as the
         "Construction Documents"). The Documents shall be prepared by an
         architect ("Tenant's Architect") experienced in the construction of
         tenant improvements in first-class buildings in the Boston area,
         retained by Tenant and approved by Landlord in advance. Landlord hereby
         approves Gensler and Associates as Tenant's Architect. There shall be
         no requirement for Tenant to use any particular building standard
         materials or items; however, the TIW shall be consistent with tenant
         improvements typically installed in comparable first-class office
         buildings in Boston. Tenant shall also retain at market rates the
         services of the mechanical, electrical, plumbing and structural
         engineers engaged by Landlord for the Base Building Work ("Landlord's
         Engineers") to assist in the preparation of the Documents. Tenant shall
         cause Tenant's Architect to perform all architectural services
         typically and reasonably required under typical construction contracts
         for similar leasehold improvements and shall be solely responsible for
         the cost of all architectural and engineering services required for the
         TIW. The Construction Documents shall comply with all applicable laws,
         ordinances and regulations (including, without limitation, the
         applicable requirements of the ADA) and shall be in a form satisfactory
         to appropriate governmental authorities responsible for issuing the
         permits, approvals and licenses required for construction. Tenant's
         interior furnishings (i.e., specifications, coordination, supply and
         installation of furniture, furnishings, telephone and moveable
         equipment) will also be the responsibility of Tenant.

         (b) The Documents (and each item thereof, e.g., Tenant's design
         documents, design development documents, and final construction
         documents) shall require Landlord's

                                       16

<PAGE>



         approval, which approval shall not be unreasonably withheld,
         conditioned or delayed. Landlord will give Tenant notice ("Landlord
         Plan Notice") of any objections it may have with respect to any
         Documents promptly after Landlord's receipt thereof. Landlord shall not
         be deemed unreasonable for withholding approval of such plans and
         specifications which (i) involve or affect any structural or exterior
         element of the Building or any portion thereof, (ii) would require
         changes in the Base Building, (iii) might, in Landlord's reasonable
         opinion, materially adversely affect the value of the Building or any
         portion thereof, (iv) materially adversely affect the proper
         functioning of the Building systems or other facilities, or (v) will
         increase the cost of construction or insurance or Taxes on the Building
         or any portion thereof, unless Tenant first gives assurances acceptable
         to Landlord for payment of such increased cost.

         (c) Tenant shall cause the Documents to be revised in a manner
         sufficient to remedy Landlord's objections and/or respond to Landlord's
         concerns and redelivered to Landlord as soon as reasonably possible
         after Tenant is given a Landlord Plan Notice and shall use diligence to
         complete the Construction Documents.

         (d) Landlord's approval of any plans and specifications furnished to
         and approved by Landlord, or of any changes thereto, shall in no way be
         deemed an agreement by Landlord that the work contemplated therein
         fulfills the requirements of Section 3.3(a) hereof. Tenant shall be
         responsible for the design of the TIW.

         (e) Core drilling for the TIW shall be permitted, subject to prior
         review and approval by Landlord's Engineers and scheduling with
         Landlord so as not to disturb other Tenants.

         (f) Landlord agrees that the TIW may include an internal stairway (the
         "Stairway") between the Premises on the 7th and 8th floors provided
         that:

                  (1) the location of the Stairway and all other particulars
                      thereof shall be set forth in the Documents which shall be
                      subject to Landlord's approval in accordance herewith;

                  (2) there shall not be more than 1 Stairway in the Premises;

                  (3) the Stairway shall comply with all applicable building
                      code requirements and the slab around the stair opening
                      penetration in the 8th floor shall be reinforced to the
                      extent reasonably required by Landlord; and

                  (4) unless otherwise agreed by Landlord in writing, upon the
                      expiration or earlier termination of the term hereof,
                      Tenant shall be required to remove the Stairway and
                      restore the area in which it was located to the condition
                      it was in before the installation thereof, including,
                      without limitation, in-filling the stair opening
                      penetration and reinforcing the same so that the in-filled
                      slab has the load bearing capacity and other
                      characteristics set forth in Section H of Exhibit D
                      attached hereto.

                                       17

<PAGE>



3.4      TENANT'S CONTRACTOR. (a) Tenant agrees to employ for the TIW a
         responsible general contractor reasonably approved by Landlord who
         shall (1) employ, and hire subcontractors who employ, union labor to do
         all union trade work, (2) employ, and hire subcontractors who employ,
         labor which will work without interference with other labor working on
         the Premises or Building for any work that is not union trade work, and
         (3) carry builder's risk insurance covering Landlord and Tenant as
         their interest may appear, against loss or damage by fire, vandalism,
         malicious mischief and such risks as are customarily covered by a
         so-called "extended coverage endorsement" to the full insurable value
         of the TIW, in addition to all other insurance required by Section
         6.2.5 and submit certificates evidencing such coverage to Landlord
         prior to the commencement of the TIW. Tenant shall obtain Landlord's
         approval of the Construction Documents for the TIW and all necessary
         governmental licenses and permits therefor and deliver to Landlord the
         statements and insurance certificates required under Section 6.2.5 on
         or before the Commencement Date for the part of the Premises in
         question and promptly thereafter Tenant shall commence and diligently
         prosecute to completion the TIW in accordance with the Construction
         Documents in a good and workmanlike manner employing materials of good
         quality and in compliance with all applicable zoning, building, fire,
         health and other codes, regulations, ordinances and laws. Any changes
         in the Construction Documents shall require Landlord's prior written
         approval, which shall not be unreasonably withheld, conditioned or
         delayed. The TIW shall otherwise be performed in accordance with the
         applicable provisions of this Lease, including, without limitation,
         Section 6.2.5 hereof.

         (b) With Landlord's prior written consent (which may be withheld
         without challenge for unreasonableness), Tenant may enter the Premises
         prior to the Commencement Date in order to commence the TIW therein but
         only if in Landlord's judgement it can be done without interference
         with Landlord's Work. Any such entry shall be upon all of the terms and
         conditions of this Lease except that no rent shall be payable therefor.
         Tenant shall have the right to enter each part of the Premises from and
         after the Commencement Date therefor to perform the TIW therein, and
         shall have the right to occupy any part of the Premises for the
         Permitted Uses prior to the Fixed Rent Commencement Date therefor (and
         without triggering an obligation to pay Fixed Rent) upon satisfaction
         of the requirements for the final advance of the Allowance for such
         part of the Premises under Section 3.5 below. Tenant shall provide a
         project manager who will be the point of contact with Landlord's
         Project Manager for all matters dealing with the design and
         construction of the TIW.

3.5      FUNDING OF ALLOWANCE. (a) Landlord shall pay to Tenant a contribution
         toward the cost of the TIW in the Initial Space, the Additional Space
         and the Expansion Space, in an amount not to exceed the Allowance for
         the Initial Space, Additional Space and Expansion Space, respectively,
         in accordance with and subject to the requirements of this Section 3.5.
         When Tenant has incurred costs for the TIW in any part of the Premises,
         Tenant shall submit to Landlord from time to time (but not more
         frequently than monthly) requisitions for payment, in the form of AIA
         Document G702 setting forth any

                                       18

<PAGE>



         costs incurred for the TIW in such part of the Premises, together with
         a partial lien waiver executed by Tenant's general contractor, and
         within 30 days following Landlord's receipt thereof, Landlord shall pay
         to Tenant the amount of each such requisition, provided that the last
         requisition hereunder shall not be paid until 30 days after Tenant's
         requisition accompanied by a written statement from Tenant's Architect
         that such TIW has been completed in accordance with Tenant's
         Construction Documents, a final lien waiver executed by Tenant's
         general contractor and a final certificate of occupancy and other
         required governmental approvals for such TIW. The costs of the TIW
         shall include all costs incurred by Tenant for architectural and
         engineering fees, hard construction, telecommunications equipment and
         for purchase and installation of improvements (but excluding any trade
         fixtures or personal property); provided, however, that the amount of
         the Allowance for any part of the Premises that shall be available for
         architectural and engineering services and other soft costs and
         relocation expenses shall be limited to $7 per square foot of Rentable
         Area of such part of the Premises. Landlord shall be entitled to deduct
         from the Allowance an amount sufficient to reimburse Landlord for its
         actual costs in connection with the TIW including additional security
         if reasonably required as a result of TIW, the costs of any freight
         elevator operation in excess of normal use and a construction
         management fee equal to 1% of TIW hard costs and general conditions.
         Subject to the limitation in the second preceding sentence, in the
         event Tenant does not use the entire Allowance for any part of the
         Premises as described above, such unused Allowance may be applied by
         Tenant toward such reasonable costs incurred in connection with any
         other portion of the Premises or for its relocation to the Premises,
         payable by Landlord to Tenant within 30 days of receipt of appropriate
         third party invoices or paid receipts. Tenant shall not be entitled to
         any payment or credit for any portion of the Allowance that is not used
         for the purposes permitted hereunder. If any lien is filed against the
         Property or any part thereof or interest therein arising out of or in
         connection with any TIW and such lien or encumbrance is not discharged,
         insured or bonded over or otherwise disposed of to Landlord's
         reasonable satisfaction within 10 days after the filing or
         establishment thereof, then Landlord shall have no further obligation
         to disburse any funds from the Allowance to Tenant unless and until the
         same is so discharged or otherwise disposed, in addition to, and not in
         lieu of, Landlord's rights and remedies and Tenant's obligations on
         account thereof under Section 3.6 or otherwise.

         (b) If Landlord fails to pay Tenant any portion of the Allowance
         properly payable by Landlord to Tenant under Section 3.5(a) hereof and
         such failure continues for 30 days after written notice thereof from
         Tenant to Landlord and any Superior Mortgagee, then Tenant shall have,
         as Tenant's sole and exclusive remedy, the right to set-off the amount
         thereof against the rent next payable by Tenant hereunder until the
         aggregate amount so set-off by Tenant shall equal the amount due from
         Landlord.

3.6      MECHANIC'S LIENS. Tenant hereby indemnifies Landlord against liability
         for any and all mechanic's and other liens filed in connection with the
         TIW or any other work performed by Tenant under this Lease. Tenant, at
         its expense, shall procure the discharge of, or shall bond over, all
         such liens within 10 days after the filing of any such lien against the
         Premises or the Property. If Tenant shall fail to cause any such lien
         to be discharged or

                                       19



<PAGE>



         bonded over within the period aforesaid, then, in addition to any other
         right or remedy, Landlord may, but shall not be obligated to, discharge
         the same either by paying the amount claimed to be due or by deposit or
         bonding proceedings, and in any such event Landlord shall be entitled,
         if it elects, to compel the prosecution of an action for the
         foreclosure of such lien and to pay the amount of the judgment in favor
         of the lienor with interest, costs and allowances. Any amount so paid
         by Landlord, and all costs and expenses reasonably incurred by Landlord
         in connection therewith, shall constitute additional rent and shall be
         paid by Tenant to Landlord on demand.


                                    ARTICLE 4

                                      RENT

4.1      FIXED RENT. (a) From and after the Fixed Rent Commencement Date for
         each part of the Premises, Tenant covenants and agrees to pay rent to
         Landlord at the Original Address of Landlord or at such other place or
         to such other person or entity as Landlord may by notice in writing to
         Tenant from time to time direct, at the Annual Fixed Rent Rate, in
         equal installments at the Monthly Fixed Rent Rate (which is 1/12th of
         the Annual Fixed Rent Rate), for the applicable Fixed Rent Period, in
         advance, on the first day of each calendar month thereafter included in
         the term without abatement, offset, deduction or counterclaim except as
         otherwise expressly provided herein; and for any portion of a calendar
         month at the beginning or end of the term, at that rate prorated on a
         daily basis payable in advance for such portion.

         (b) Tenant acknowledges and agrees that the Annual Fixed Rent Rate may
         not be reduced by agreement of Landlord and Tenant without the prior
         written consent of Massport, except pursuant to the express provisions
         of this Lease.

4.2      ADDITIONAL RENT.  Tenant covenants and agrees to pay the following,
         as additional rent:

         4.2.1    REAL ESTATE TAXES.  (a) Tenant shall pay the following amounts
                  as additional rent during the following periods:

                  (1) during the period from the Fixed Rent Commencement Date
                      for the Initial Space through the day before the Fixed
                      Rent Commencement Date for the Expansion Space, Tenant
                      shall pay to Landlord, as additional rent, Tenant's Tax
                      Percentage for the Initial Space of the amount if any by
                      which the Tax Obligation for such period exceeds Base
                      Taxes;

                  (2) during the period from the Fixed Rent Commencement Date
                      for the Initial Space through the day before the Fixed
                      Rent Commencement Date for the Additional Space, Tenant
                      shall pay to Landlord, Tenant's Tax Percentage for the
                      Additional Space of the Tax Obligation for such period;

                                       20


<PAGE>

                  (3) during the period from the Fixed Rent Commencement Date
                      for the Additional Space through the day before the Fixed
                      Rent Commencement Date for the Expansion Space, Tenant
                      shall pay Landlord, Tenant's Tax Percentage for the
                      Additional Space of the amount (if any) by which the Tax
                      Obligation for such period exceeds Base Taxes;

                  (4) during the period from the Fixed Rent Commencement Date
                      for the Initial Space through the day before the Fixed
                      Rent Commencement Date for the Expansion Space, Tenant
                      shall pay Landlord Tenant's Tax Percentage for the
                      Expansion Space of the Tax Obligation for such period; and

                  (5) from and after the Fixed Rent Commencement Date for the
                      Expansion Space, Tenant shall pay to Landlord Tenant's Tax
                      Percentage for the entire Premises of the amount (if any)
                      by which the Tax Obligation for each Tax Year or part
                      thereof exceeds the Tax Base.

                  The additional rent payable by Tenant under the preceding
                  sentence is referred to herein as "Tenant's Share of Taxes."
                  In calculating Tenant's Share of Taxes for any period that is
                  less than 12 months, the Tax Base shall be prorated on a daily
                  basis. For so long as the 6A Contract remains in effect, the
                  "Tax Obligation" for any Tax Year shall be defined as the 6A
                  Payment for such Tax Year; and if the 6A Contract is
                  terminated or expires at any time during the term and Taxes
                  are assessed on the Property, the "Tax Obligation" for all or
                  part of any Tax Year thereafter shall mean such Taxes. Tenant
                  shall remit to Landlord, on the first day of each calendar
                  month, estimated payments on account of Tenant's Share of
                  Taxes, such monthly amounts to be sufficient to provide
                  Landlord, by the time real estate tax payments are due and
                  payable to any governmental authority responsible for
                  collection of same, a sum equal to the Tenant's Share of
                  Taxes, as reasonably estimated by Landlord from time to time
                  on the basis of the most recent tax data available. If the
                  total of such monthly remittances for any Tax Year is greater
                  than the actual Tenant's Share of Taxes for such Tax Year,
                  Landlord shall promptly pay to Tenant, or credit against the
                  next accruing payments to be made by Tenant pursuant to this
                  subsection 4.2.1, the difference; if the total of such
                  remittances is less than the actual Tenant's Share of Taxes
                  for such Tax Year, Tenant shall pay the difference to Landlord
                  at least 10 days prior to the date or dates within such Tax
                  Year that any Taxes become due and payable to the governmental
                  authority (but in any event no earlier than 10 business days
                  following a written notice to Tenant, which notice shall set
                  forth the manner of computation of Tenant's Share of Taxes).

                  (b) If, after Tenant shall have made reimbursement to
                  Landlord pursuant to this subsection 4.2.1, Landlord shall
                  receive a refund of any portion of Taxes paid by Tenant with
                  respect to any Tax Year during the term hereof as a result of
                  an abatement of such Taxes by legal proceedings, settlement or
                  otherwise (without Landlord having any obligation to undertake
                  any such proceedings), Landlord

                                       21

<PAGE>

                  shall promptly pay to Tenant, or credit against the next
                  accruing payments to be made by Tenant pursuant to this
                  subsection 4.2.1, the Tenant's Tax Percentage of the refund
                  (less the proportional, pro rata expenses, including
                  attorneys' fees and appraisers' fees, incurred in connection
                  with obtaining any such refund), as relates to Tenant's Share
                  of Taxes paid by Tenant to Landlord with respect to any Tax
                  Year for which such refund is obtained.

                  (c) In the event this Lease shall commence, or shall
                  end (by reason of expiration of the term or earlier
                  termination pursuant to the provisions hereof), on any date
                  other than the first or last day of the Tax Year, or should
                  the Tax Year or period of assessment of real estate taxes be
                  changed or be more or less than 1 year, as the case may be,
                  then the amount of Tenant's Share of Taxes which may be
                  payable by Tenant as provided in this subsection 4.2.1 shall
                  be appropriately apportioned and adjusted.

                  (d) The term "Taxes" shall mean all taxes, assessments,
                  betterments and other charges and impositions (including, but
                  not limited to, fire protection service fees and similar
                  charges) levied, assessed or imposed at any time during the
                  term by any governmental authority upon or against the
                  Property, or taxes in lieu thereof, and additional types
                  of taxes to supplement real estate taxes due to legal limits
                  imposed thereon. If, at any time during the term of this
                  Lease, any tax or excise on rents or other taxes, however
                  described, are levied or assessed against Landlord with
                  respect to the rent reserved hereunder, either wholly or
                  partially in substitution for, or in addition to, real estate
                  taxes assessed or levied on the Property, such tax or excise
                  on rents shall be included in Taxes; however, Taxes shall not
                  include franchise, estate, inheritance, succession, capital
                  levy, transfer, income or excess profits taxes assessed on
                  Landlord. Taxes shall include any estimated payment made by
                  Landlord on account of a fiscal tax period for which the
                  actual and final amount of taxes for such period has not been
                  determined by the governmental authority as of the date of
                  any such estimated payment.

                  (e) The term "6A Payment" shall mean an amount equal
                  to the product of (1) the rate per square foot under Exhibit A
                  of the 6A Contract applicable to the period in question for
                  occupied and vacant space, if applicable, times (2) the Total
                  Rentable Area of the Building that is occupied and vacant, if
                  applicable, respectively.

                  (f) The term "6A Contract" shall mean a certain contract dated
                  June 30, 1998 between the City of Boston and Commonwealth
                  Flats Development 121A East Limited Partnership, a
                  Massachusetts limited partnership ("121A Owner") which has
                  leased the Property to Landlord, pursuant to Section 6A of
                  Chapter 121A of the Massachusetts General Laws, a copy of
                  which has been delivered to Tenant, pursuant to which certain
                  payments provided for thereunder are to be made in lieu of
                  real estate taxes on the Property.

                                       22

<PAGE>



         4.2.2    PERSONAL PROPERTY TAXES. Tenant shall pay all taxes charged,
                  assessed or imposed upon the personal property of Tenant in or
                  upon the Premises.

         4.2.3    OPERATING COSTS. (a) Tenant shall pay Landlord, as additional
                  rent, the following amounts during the following periods:

                  (1) during the period from the Fixed Rent Commencement Date
                      for the Initial Space through the day before the Fixed
                      Rent Commencement Date for the Expansion Space, Tenant
                      shall pay to Landlord, as additional rent, Tenant's Office
                      Percentage for the Initial Space of the amount if any by
                      which the Operating Costs for such period exceed Base
                      Operating Costs;

                  (2) during the period from the Fixed Rent Commencement Date
                      for the Initial Space through the day before the Fixed
                      Rent Commencement Date for the Additional Space, Tenant
                      shall pay to Landlord, Tenant's Office Percentage for the
                      Additional Space of Operating Costs for such period;

                  (3) during the period from the Fixed Rent Commencement Date
                      for the Additional Space through the day before the Fixed
                      Rent Commencement Date for the Expansion Space, Tenant
                      shall pay Landlord, Tenant's Office Percentage for the
                      Additional Space of the amount (if any) by which Operating
                      Costs for such period exceed Base Operating Costs;

                  (4) during the period from the Fixed Rent Commencement Date
                      for the Initial Space through the day before the Fixed
                      Rent Commencement Date for the Expansion Space, Tenant
                      shall pay Landlord Tenant's Office Percentage for the
                      Expansion Space of Operating Costs for such period; and

                  (5) from and after the Fixed Rent Commencement Date for the
                      Expansion Space, Tenant shall pay to Landlord Tenant's
                      Office Percentage for the entire Premises of the amount
                      (if any) by which Operating Costs for any calendar year or
                      part thereof exceed Base Operating Costs for such period.

                  The additional rent payable by Tenant under the preceding
                  sentence is referred to herein as "Tenant's Share of Operating
                  Costs." In calculating Tenant's Share of Operating Costs for
                  any period that is less than 12 months, Base Operating Costs
                  shall be prorated on a daily basis. Tenant shall remit to
                  Landlord, on the first day of each calendar month, estimated
                  payments on account of Tenant's Share of Operating Costs, such
                  monthly amounts to be sufficient to provide Landlord, by the
                  end of the calendar year, a sum equal to the Tenant's Share of
                  Operating Costs, as reasonably estimated by Landlord from time
                  to time. If, at the expiration of the year in respect of which
                  monthly installments of Tenant's Share of Operating Costs
                  shall have been made as aforesaid, the total of such monthly
                  remittances is greater than the actual Tenant's Share of
                  Operating Costs for such year, Landlord shall promptly pay to
                  Tenant, or credit against the next accruing

                                       23

<PAGE>



                  payments to be made by Tenant pursuant to this subsection
                  4.2.3, the difference; if the total of such remittances is
                  less than the Tenant's Share of Operating Costs for such year,
                  Tenant shall pay the difference to Landlord within 20 days
                  from the date Landlord shall furnish to Tenant an itemized
                  statement of the Tenant's Share of Operating Costs, prepared,
                  allocated and computed in accordance with generally accepted
                  accounting principles. Any reimbursement for Operating Costs
                  due and payable by Tenant with respect to periods of less than
                  12 months shall be equitably prorated.

                  (b) The term "Operating Costs" shall mean all costs or
                  expenses incurred for the operation, cleaning, maintenance,
                  repair and upkeep of the Property, including, without
                  limitation, all costs of maintaining and repairing the
                  Property (including snow removal, security, operation and
                  repair of heating and air-conditioning equipment, elevators,
                  lighting and any other Building equipment or systems) and of
                  all repairs and replacements (other than repairs or
                  replacements for which Landlord has received full
                  reimbursement from contractors, other tenants of the Building
                  or from others) necessary to keep the Property in good working
                  order, repair, appearance and condition; all costs, including
                  material and equipment costs, for cleaning and janitorial
                  services to the Building (including window cleaning of the
                  Building); all costs of any reasonable insurance carried by
                  Landlord relating to the Property; all costs related to
                  provision of heat (including oil, electric, steam and/or gas),
                  air-conditioning, ventilation, and water (including sewer
                  charges) and other utilities to the Building (exclusive of
                  reimbursement to Landlord for any of same received as a result
                  of direct billing to any tenant of the Building); payments
                  under all service contracts relating to the foregoing; all
                  compensation, fringe benefits, payroll taxes and worker's
                  compensation insurance premiums related thereto with respect
                  to any employees of Landlord or its affiliates or manager
                  directly engaged in security and maintenance of the Property
                  at or below the grade of general manager; attorneys' fees and
                  disbursements (exclusive of any such fees and disbursements
                  incurred in tax abatement proceedings or the preparation or
                  enforcement of leases) and auditing and other professional
                  fees and expenses; shuttle services; a management fee which
                  shall not exceed the market rate for owner managed buildings;
                  fire protection service fees and similar governmental charges;
                  and the portion fairly allocable to the Property of any and
                  all of the foregoing costs incurred with regard to the
                  operation, maintenance and repair of the structural support
                  system and other elements and facilities which are shared by
                  the Property and the Garage.

                  (c) There shall not be included in such Operating Costs (1)
                  brokerage fees (including rental fees) related to the
                  operation of the Building; (2) interest and depreciation
                  charges incurred on the Property; (3) expenditures made by
                  Tenant with respect to (x) cleaning, maintenance and upkeep of
                  the Premises, or (y) the provision of electricity to the
                  Premises, (3) costs and expenses incurred with respect to or
                  fairly allocable to the Retail Area, (4) ground lease
                  payments, (5) costs to repair any item of Landlord's Work
                  which was not constructed in

                                       24

<PAGE>



                  accordance with the plans and specifications therefor or any
                  item of the Base Building Work that was not designed in
                  accordance with applicable laws as of the Commencement Date,
                  (6) costs for which Landlord is reimbursed by insurance,
                  taking awards, warranties or as direct charges to other
                  tenants (as opposed to their share of Operating Costs), (7)
                  any payments to any affiliates of Landlord (other than the
                  management fee provided for above) for services in excess of
                  the costs of arms-length, third-party providers for services
                  of comparable quality and scope, and (8) legal and other fees
                  for financing, sale or ownership organizational matters of
                  Landlord.

                  (d) If, during the term of this Lease, Landlord shall replace
                  any capital items or make any capital expenditures
                  (collectively called "capital expenditures") the total amount
                  of which is not properly included in Operating Costs for the
                  calendar year in which they were made, there shall
                  nevertheless be included in Operating Costs for each calendar
                  year in which and after such capital expenditure is made the
                  annual charge-off of such capital expenditure. The annual
                  charge-off shall be determined by (i) dividing the original
                  cost of the capital expenditure by the number of years of
                  useful life thereof (the useful life shall be reasonably
                  determined by Landlord in accordance with generally accepted
                  accounting principles and practices in effect at the time of
                  acquisition of the capital item.); and (ii) adding to such
                  quotient an interest factor computed on the unamortized
                  balance of such capital expenditure based upon an interest
                  rate reasonably determined by Landlord as being the interest
                  rate then being charged for long-term mortgages by
                  institutional lenders on like properties within the locality
                  in which the Building is located. Provided, further, that if
                  Landlord reasonably concludes on the basis of engineering
                  estimates that a particular capital expenditure will effect
                  savings in Operating Costs and that such annual projected
                  savings will exceed the annual charge-off of capital
                  expenditure computed as aforesaid, then and in such event, the
                  annual charge-off shall be determined by dividing the amount
                  of such capital expenditure by the number of years over which
                  the projected amount of such savings shall fully amortize the
                  cost of such capital item or the amount of such capital
                  expenditure; and by adding the interest factor, as aforesaid.

                  (e) If during any portion of any year for which Operating
                  Costs are being computed, the Building was less than 95%
                  occupied by tenants, or if less than 95% of the Building is
                  occupied by tenants paying fixed rent, or if Landlord was
                  supplying the services being supplied hereunder to tenants
                  occupying less than 95% of the Building, then actual Operating
                  Costs incurred shall be reasonably extrapolated by Landlord to
                  the estimated Operating Costs that would have been incurred if
                  95% of the Building were occupied by tenants, tenants
                  occupying 95% of the Building were then paying fixed rent, and
                  such services were being supplied to tenants occupying 95% of
                  the Building, and such extrapolated amount shall, for the
                  purposes of this Section 4.2.3, be deemed to be the Operating
                  Costs for such year.

                                       25

<PAGE>



                  (f) The parties acknowledge and agree that once the MBTA
                  Silver Line is complete and operational the shuttle service
                  component of Operating Costs and Base Operating Costs
                  thereafter will be reduced appropriately to the extent that
                  Landlord reasonably determines to reduce the frequency of or
                  eliminate such service in response to a reduction in demand
                  therefor.

          4.2.4   INSURANCE. Tenant shall, at its expense, take out and maintain
                  throughout the term the following insurance protecting
                  Landlord and all Landlord Affiliates requested by Landlord:

                  4.2.4.1  Commercial general liability insurance naming
                           Landlord, Tenant, and Landlord's managing agent,
                           Landlord Affiliates and any mortgagee of which Tenant
                           has been given notice as additional insureds and
                           indemnifying the parties so named on an occurrence
                           basis against all claims and demands for death or any
                           injury to person or damage to property which may be
                           claimed to have occurred on the Premises (or the
                           Property, insofar as used by customers, employees,
                           servants or invitees of the Tenant), in amounts which
                           shall, at the beginning of the term, be at least
                           equal to the limits set forth in Section 1.1, and,
                           which, from time to time during the term, shall be
                           for such higher limits, if any, as are customarily
                           carried in the area in which the Premises are located
                           on property similar to the Premises and used for
                           similar purposes; and worker's compensation insurance
                           with statutory limits covering all of Tenant's
                           employees working on the Premises.

                  4.2.4.2  Fire insurance with the usual extended coverage
                           endorsements covering all Tenant's furniture,
                           furnishings, fixtures and equipment.

                  4.2.4.3  All such policies shall be obtained from responsible
                           companies qualified to do business and in good
                           standing in Massachusetts, which companies and the
                           amount of insurance allocated thereto shall be
                           subject to Landlord's approval, not to be
                           unreasonably withheld. Tenant agrees to furnish
                           Landlord with certificates evidencing all such
                           insurance prior to the beginning of the term hereof
                           and evidencing renewal thereof at least 30 days prior
                           to the expiration of any such policy. Each such
                           policy shall be non-cancelable with respect to the
                           interest of Landlord without at least 10 days' prior
                           written notice thereto. In the event provision for
                           any such insurance is to be by a blanket insurance
                           policy, the policy shall allocate a specific and
                           sufficient amount of coverage to the Premises.

                  4.2.4.4  All insurance which is carried by either party with
                           respect to the Building, the Premises or furniture,
                           furnishings, fixtures, or equipment therein or
                           alterations or improvements thereto, whether or not
                           required, shall include provisions which either
                           designate the other party as one of the insured or

                                       26

<PAGE>



                           deny to the insurer acquisition by subrogation of
                           rights of recovery against the other party to the
                           extent such rights have been waived by the insured
                           party prior to occurrence of loss or injury, insofar
                           as, and to the extent that, such provisions may be
                           effective without making it impossible to obtain
                           insurance coverage from responsible companies
                           qualified to do business in the state in which the
                           Premises are located (even though extra premium may
                           result therefrom). In the event that extra premium is
                           payable by either party as a result of this
                           provision, the other party shall reimburse the party
                           paying such premium the amount of such extra premium.
                           If at the request of one party, this non-subrogation
                           provision is waived, then the obligation of
                           reimbursement shall cease for such period of time as
                           such waiver shall be effective, but nothing contained
                           in this subsection shall derogate from or otherwise
                           affect releases elsewhere herein contained of either
                           party for claims. Each party shall be entitled to
                           have certificates of any policies containing such
                           provisions. Each party hereby waives all rights of
                           recovery against the other for loss or injury against
                           which the waiving party is protected by insurance
                           containing said provisions, reserving, however, any
                           rights with respect to any excess of loss or injury
                           over the amount covered by such insurance. Tenant
                           shall not acquire as insured under any insurance
                           carried on the Premises any right to participate in
                           the adjustment of loss or to receive insurance
                           proceeds and agrees upon request promptly to endorse
                           and deliver to Landlord any checks or other
                           instruments in payment of loss in which Tenant is
                           named as payee.

         4.2.5    UTILITIES. Tenant shall pay to Landlord all charges for
                  electricity supplied by Landlord and separately metered (which
                  shall include electricity for lights, outlets and heating,
                  ventilation and cooling, including reheat coils, fan boxes,
                  compressors and refrigerating units serving the Premises), and
                  to the appropriate third party all charges for telephone and
                  other utilities or services not supplied by Landlord pursuant
                  to Subsections 5.1.1, 5.1.2, and 5.1.3, whether designated as
                  a charge, tax, assessment, fee or otherwise, all such charges
                  to be paid as the same from time to time become due. Except as
                  otherwise provided in Article 5, it is understood and agreed
                  that Tenant shall make its own arrangements for the
                  installation or provision of all such utilities and that
                  Landlord shall be under no obligation to furnish any utilities
                  to the Premises and shall not be liable for any interruption
                  or failure in the supply of any such utilities to the
                  Premises, except to the extent expressly provided in Section
                  5.2 below. Notwithstanding the foregoing, if Landlord fails to
                  provide any service that it is required to provide above so
                  that Tenant cannot reasonably continue to operate its business
                  in the Premises and such failure continues for the Abatement
                  Threshold after written notice thereof from Tenant to Landlord
                  and each Superior Mortgagee and Superior Lessor of which
                  Tenant has been given notice hereunder, then, provided that
                  such failure or Landlord's inability to cure such condition is
                  not due to the fault or negligence of Tenant or any of its
                  agents, employees or contractors or a fire or other casualty
                  or taking (which shall be governed by Article 7 below), then
                  the Fixed Rent and Additional Rent shall be equitably abated
                  based

                                       27

<PAGE>

                  upon the impact thereof on Tenant's ability to conduct
                  business in the Premises until such service(s) is completely
                  restored. The "Abatement Threshold" shall mean 5 consecutive
                  business days, unless such failure or Landlord's inability to
                  cure such condition is due to a cause beyond Landlord's
                  reasonable control generally affecting other buildings in the
                  vicinity of the Premises (such as a neighborhood power outage)
                  in which case the "Abatement Threshold" shall be 30
                  consecutive days.

4.3      LATE PAYMENT OF RENT. If any installment of rent is paid after the date
         the same was due, and if on 2 or more prior occasions in the 12 month
         period prior to the date such installment was due an installment of
         rent was paid after the same was due, then Tenant shall pay Landlord a
         late payment fee equal to 5% percent of the overdue payment.

                                    ARTICLE 5

                              LANDLORD'S COVENANTS

5.1      AFFIRMATIVE COVENANTS.  Landlord covenants with Tenant:

         5.1.1    HEAT AND AIR-CONDITIONING. (a) To furnish condenser water to
                  the air handling units serving the Premises (reserving the
                  right, at any time, to change energy sources) sufficient to
                  enable Tenant to maintain the Premises at comfortable
                  temperatures (subject to all federal, state, and local
                  regulations relating to the provision of heat and the Air
                  Conditioning Design Conditions) during Normal Business Hours
                  by the operation of the system of air handling units,
                  refrigerating units, VAV boxes and reheat coils that serve the
                  Premises which are connected to Tenant's separately metered
                  electrical system, the charges for which Tenant is responsible
                  under Section 5.1.2 below. The "Air Conditioning Design
                  Conditions" shall be 78 degrees F dry bulb and 50% relative
                  humidity with outside conditions of 91 degrees F dry bulb and
                  75 degrees F wet bulb, based upon an occupancy within each
                  separately partitioned area in the Premises of not more than 1
                  person per 150 feet of Rentable Area and a combined lighting
                  and standard electrical load not to exceed 6 watts per square
                  foot of Rentable Area.

                  (b) If Tenant shall require condenser water outside Normal
                  Business Hours, Landlord shall, upon the written request of
                  Tenant received at least 24 hours prior to the time such
                  additional air conditioning or heat is required, but only to
                  the extent it is reasonably able to do so, furnish such
                  service or cause such service to be furnished and Tenant shall
                  pay therefor such reasonable charges as may from time to time
                  be established by Landlord and be in effect to cover
                  Landlord's incremental costs of providing such service.
                  Landlord currently estimates that the initial rate for such
                  service will be $25 per floor per hour, but the actual rate
                  may vary or be changed at any time and from time to time in
                  accordance with and subject to the preceding sentence.

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<PAGE>



         5.1.2    ELECTRICITY. To furnish to the Premises, separately metered
                  and at the direct expense of Tenant as provided in Section
                  4.2.5, up to 6 watts per square foot of Rentable Area of the
                  Premises of electricity for Tenant's Permitted Uses (i.e., 2
                  watts for lighting and 4 watts for general power). If Tenant
                  shall require electricity in excess of such 6 watts per square
                  foot of Rentable Area of the Premises for Tenant's Permitted
                  Uses, an additional 3 watts per square foot of Rentable Area
                  of the Premises is available at the floor electrical room,
                  which may be brought to the Premises at Tenant's expense.

         5.1.3    CLEANING; WATER. To provide cleaning to the Premises and the
                  common areas of the Building substantially in accordance with
                  Exhibit F, Office Space Cleaning Specifications; and to
                  furnish water for ordinary cleaning, lavatory and toilet
                  facilities.

         5.1.4    ELEVATOR SERVICE. To furnish 24 hour elevator service from the
                  lobby to the Premises.

         5.1.5    SECURITY. To furnish at least 1 lobby attendant in the
                  Building 24 hours per day, and a card access control system
                  for access to the Building and Premises after Normal Business
                  Hours, which, in conjunction with the elevator system, will be
                  capable of limiting floor by floor access in the Building
                  after Normal Business Hours.

         5.1.6    REPAIRS. Except as otherwise expressly provided herein, to
                  make such repairs and replacements to the roof, exterior
                  walls, floor slabs and other structural components of the
                  Building, and to the common areas, facilities and plumbing,
                  electrical, heating, ventilating and air-conditioning systems
                  of the Building as may be necessary to keep them in good
                  repair and condition (exclusive of equipment installed by
                  Tenant and except for those repairs required to be made by
                  Tenant pursuant to Section 6.1.3 hereof and repairs or
                  replacements occasioned by any act or negligence of Tenant,
                  its servants, agents, customers, contractors, employees,
                  invitees, or licensees). Landlord will provide and maintain
                  fire extinguishers in the common areas of the Building as
                  required by law and Tenant shall provide and maintain them in
                  the Premises as required by law. Landlord shall also maintain
                  the fire alarm speakers, strobes and alarms within the
                  Premises.

         5.1.7    SHUTTLE SERVICE. To cause shuttle service to and from the
                  Boston Financial District to be provided with frequent
                  headways scheduled (at least every 15 minutes during Normal
                  Business Hours) until the MBTA Silver Line is available to the
                  Building whereupon service will be reduced in frequency or
                  eliminated to reflect any reduction in demand therefor as
                  reasonably determined by Landlord.

         5.1.8    INDEMNIFICATION. To save Tenant harmless, and to exonerate and
                  indemnify Tenant from and against any and all claims,
                  liabilities or penalties asserted by or

                                       29

<PAGE>



                  on behalf of any person, firm, corporation or public authority
                  on account of injury, death, damage or loss to person or
                  property in or upon the common areas of the Building and the
                  Property to the extent caused by the negligence, fault or
                  misconduct of Landlord or any of its agents, employees or
                  contractors. The foregoing indemnity shall include all costs,
                  expenses (including reasonable attorneys' fees), and
                  liabilities incurred by Tenant in or in connection with any
                  such claim. In case of any action or proceeding brought
                  against Tenant by reason of any such claim, Tenant shall give
                  Landlord prompt notice thereof and Landlord, upon notice from
                  Tenant and at Landlord's expense, shall resist or defend such
                  action or proceeding.

5.2      INTERRUPTION. Landlord shall be under no responsibility or liability
         for failure or interruption of any of the above-described services,
         repairs or replacements caused by breakage, accident, strikes, repairs,
         inability to obtain supplies, labor or materials, or for any other
         causes beyond the reasonable control of the Landlord, and in no event
         for any indirect or consequential damages to Tenant; and failure or
         omission on the part of the Landlord to furnish any of same for any of
         the reasons set forth in this paragraph shall not be construed as an
         eviction of Tenant, actual or constructive, nor entitle Tenant to an
         abatement of rent, nor render the Landlord liable in damages, nor
         release Tenant from prompt fulfillment of any of its covenants under
         this Lease, except to the extent provided in Section 4.2.5.

5.3      OUTSIDE SERVICES. In the event Tenant wishes to provide outside
         services for the Premises over and above those services to be provided
         by Landlord as set forth herein, Tenant shall first obtain the prior
         written approval of Landlord for the installation and/or utilization of
         such services ("outside services" shall include, but shall not be
         limited to, cleaning services, television, so-called "canned music"
         services, security services, catering services and the like), such
         approval not to be unreasonably withheld or delayed. In the event
         Landlord approves the installation and/or utilization of such services,
         such installation and utilization shall be at Tenant's sole cost, risk
         and expense.


                                    ARTICLE 6

                          TENANT'S ADDITIONAL COVENANTS

6.1      AFFIRMATIVE COVENANTS. Tenant covenants at all times during the term
         and for such further time (prior or subsequent thereto) as Tenant
         occupies the Premises or any part thereof:

         6.1.1    PERFORM OBLIGATIONS. To perform promptly all of the
                  obligations of Tenant set forth in this Lease; and to pay when
                  due the Fixed Rent and additional rent and all charges, rates
                  and other sums which by the terms of this Lease are to be paid
                  by Tenant.

                                       30

<PAGE>

         6.1.2    USE. To use the Premises only for the Permitted Uses, and from
                  time to time to procure all licenses and permits necessary
                  therefor, at Tenant's sole expense, except that building
                  permits for Landlord's Work and the certificate of occupancy
                  for the base building shall be obtained by Landlord. All
                  licenses, permits and approvals required for the TIW
                  (including, without limitation, the building permit and
                  certificate of occupancy) shall be obtained by Tenant. With
                  respect to any licenses or permits for which Tenant may apply,
                  pursuant to this subsection 6.1.2 or any other provision
                  hereof, Tenant shall furnish Landlord copies of applications
                  therefor on or before their submission to the governmental
                  authority.

         6.1.3    REPAIR AND MAINTENANCE. To maintain the Premises in neat order
                  and condition and to perform all routine and ordinary repairs
                  to the Premises and to any plumbing, heating, electrical,
                  ventilating and air-conditioning systems located within the
                  Premises and installed by Tenant such as are necessary to keep
                  them in good working order, appearance and condition, as the
                  case may require, reasonable use and wear thereof and damage
                  by fire or casualty only excepted; to keep all glass in
                  windows and doors of the Premises (except glass in the
                  exterior walls of the Building) whole and in good condition
                  with glass of the same quality as that injured or broken; and
                  to make as and when needed as a result of misuse by, or
                  neglect or improper conduct of Tenant or Tenant's servants,
                  employees, agents, invitees or licensees or otherwise, all
                  repairs necessary, which repairs and replacements shall be in
                  quality and class equal to the original work. (Landlord, upon
                  default of Tenant hereunder and upon prior notice to Tenant,
                  may elect, at the expense of Tenant, to perform all such
                  cleaning and maintenance and to make any such repairs or to
                  repair any damage or injury to the Building or the Premises
                  caused by moving property of Tenant in or out of the Building,
                  or by installation or removal of furniture or other property,
                  or by misuse by, or neglect, or improper conduct of, Tenant or
                  Tenant's servants, employees, agents, contractors, customers,
                  patrons, invitees, or licensees.)

         6.1.4    COMPLIANCE WITH LAW. To make all repairs, alterations,
                  additions or replacements to the Premises required by any law
                  or ordinance or any order or regulation of any public
                  authority; to keep the Premises equipped with all safety
                  appliances (other than those to be maintained by Landlord
                  under Section 5.1.6 above) so required; and to comply with the
                  orders and regulations of all governmental authorities with
                  respect to zoning, building, fire, health and other codes,
                  regulations, ordinances or laws applicable to the Premises,
                  except that Tenant may defer compliance so long as the
                  validity of any such law, ordinance, order or regulations
                  shall be contested by Tenant in good faith and by appropriate
                  legal proceedings, if Tenant first gives Landlord appropriate
                  assurance or security against any loss, cost or expense on
                  account thereof.

         6.1.5    INDEMNIFICATION. To save Landlord and all Landlord Affiliates
                  harmless, and to exonerate and indemnify Landlord from and
                  against any and all claims, liabilities or penalties asserted
                  by or on behalf of any person, firm, corporation or public


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<PAGE>



                  authority on account of injury, death, damage or loss to
                  person or property in or upon the Premises or the negligence
                  or willful misconduct of Tenant or any of its agents,
                  employees or contractors outside of the Premises, except to
                  the extent the same was caused by the willful negligence,
                  fault or misconduct of Landlord, its agents, employees or
                  contractors. In respect of all of the foregoing, Tenant shall
                  indemnify Landlord from and against all costs, expenses
                  (including reasonable attorneys' fees), and liabilities
                  incurred in or in connection with any such claim, action or
                  proceeding brought thereon; and, in case of any action or
                  proceeding brought against Landlord by reason of any such
                  claim, Tenant, upon notice from Landlord and at Tenant's
                  expense, shall resist or defend such action or proceeding.

         6.1.6    LANDLORD'S RIGHT TO ENTER. To permit Landlord and its agents
                  to enter into and examine the Premises at reasonable times
                  upon reasonable advance notice (except in emergencies) and to
                  show the Premises, and to make repairs to the Premises, and,
                  during the last 12 months prior to the expiration of this
                  Lease, to keep affixed in suitable places notices of
                  availability of the Premises.

         6.1.7    PERSONAL PROPERTY AT TENANT'S RISK. All of the furnishings,
                  fixtures, equipment, effects and property of every kind,
                  nature and description of Tenant and of all persons claiming
                  by, through or under Tenant which, during the continuance of
                  this Lease or any occupancy of the Premises by Tenant or
                  anyone claiming under Tenant, may be on the Premises, shall be
                  at the sole risk and hazard of Tenant and if the whole or any
                  part thereof shall be destroyed or damaged by fire, water or
                  otherwise, or by the leakage or bursting of water pipes, steam
                  pipes, or other pipes, by theft or from any other cause, no
                  part of said loss or damage is to be charged to or to be borne
                  by Landlord, except that Landlord shall in no event be
                  indemnified or held harmless or exonerated from any liability
                  to Tenant or to any other person, for any injury, loss, damage
                  or liability to the extent prohibited by law.

         6.1.8    YIELD UP. (a) At the expiration of the term or earlier
                  termination of this Lease: to surrender all keys to the
                  Premises; to remove all of its trade fixtures and personal
                  property in the Premises; to remove such installations made by
                  it as Landlord may request (which Landlord will make upon
                  Tenant's request at the time Landlord approves thereof ) and
                  all Tenant's signs wherever located,; to repair all damage
                  caused by such removal and to yield up the Premises (including
                  all installations and improvements made by Tenant except for
                  trade fixtures and such of said installations or improvements
                  as Landlord shall request Tenant to remove), broom-clean and
                  in the same good order and repair in which Tenant is obliged
                  to keep and maintain the Premises by the provisions of this
                  Lease. Any property not so removed shall be deemed abandoned
                  and, if Landlord so elects, deemed to be Landlord's property,
                  and may be retained or removed and disposed of by Landlord in
                  such manner as Landlord shall determine and Tenant shall pay
                  Landlord the entire cost and expense incurred by it in
                  effecting such removal and disposition and in making any
                  incidental repairs and replacements to the Premises and for
                  use

                                       32

<PAGE>



                  and occupancy during the period after the expiration of
                  the term and prior to its performance of its obligations under
                  this subsection 6.1.8. Tenant shall further indemnify Landlord
                  against all loss, cost and damage resulting from Tenant's
                  failure and delay in surrendering the Premises as above
                  provided.

                  (b) If the Tenant remains in the Premises beyond the
                  expiration or earlier termination of this Lease, such holding
                  over shall be without right and shall not be deemed to create
                  any tenancy, but the Tenant shall be a tenant at sufferance
                  only at a daily rate of rent (1) during the first 30 days
                  after the termination of the term equal to the greater of (x)
                  1.5 times the rent and other charges in effect under this
                  Lease as of the day prior to the date of expiration of this
                  Lease, or (y) the fair market value of the Premises, and (2)
                  thereafter, 2 times the rent and other charges in effect under
                  this Lease as of the day prior to the date of expiration
                  hereof.

         6.1.9    RULES AND REGULATIONS. To comply with the Rules and
                  Regulations set forth in Exhibit G, and with all reasonable
                  Rules and Regulations of general applicability to all tenants
                  of the Building hereafter made by Landlord, of which Tenant
                  has been given notice; Landlord shall not be liable to Tenant
                  for the failure of other tenants of the Building to conform to
                  such Rules and Regulations.

         6.1.10   ESTOPPEL CERTIFICATE. Upon not less than 15 days' prior
                  written request by Landlord, to execute, acknowledge and
                  deliver to Landlord a statement in writing in the form
                  attached hereto as Exhibit H, certifying all or any of the
                  following: (i) that this Lease is unmodified and in full force
                  and effect (or, if there have been any modifications stating
                  such modifications), (ii) whether the term has commenced and
                  Fixed Rent and additional rent have become payable hereunder
                  and, if so, the dates to which they have been paid, (iii)
                  whether or not Landlord is in default in performance of any of
                  the terms of this Lease, and, if so, specifying such defaults,
                  (iv) whether Tenant has accepted possession of the Premises,
                  (v) whether Tenant has made any claim against Landlord under
                  this Lease and, if so, the nature thereof and the dollar
                  amount, if any, of such claim, (vi) whether there exist any
                  offsets or defenses against enforcement of any of the terms of
                  this Lease upon the part of Tenant to be performed, and, if
                  so, setting them forth in reasonable detail, and (vii) such
                  further information with respect to the Lease or the Premises
                  as Landlord may reasonably request. Landlord shall provide
                  similar statements to Tenant upon not less than 15 days' prior
                  written request by Tenant. Any such statement delivered
                  pursuant to this subsection 6.1.10 may be relied upon by any
                  prospective purchaser or mortgagee of the Premises, or any
                  prospective assignee of such mortgage or any prospective
                  lender, subtenant, assignee or other successor to Tenant.
                  Tenant shall also deliver to Landlord such financial
                  information as may be reasonably required by Landlord to be
                  provided to any mortgagee or prospective purchaser of the
                  Property.

         6.1.11   NON-DISCRIMINATION AND AFFIRMATIVE ACTION. Tenant agrees to
                  comply with the Non-Discrimination and Affirmative Action
                  Covenants set forth in Section 14.1

                                       33

<PAGE>



                  of the Massport Lease, as copy of which is attached hereto as
                  Exhibit I, wherein the term "Tenant" shall mean Tenant
                  hereunder and "Landlord" shall mean the Landlord under the
                  Massport Lease.

6.2      NEGATIVE COVENANTS. Tenant covenants at all times during the term and
         such further time (prior or subsequent thereto) as Tenant occupies the
         Premises or any part thereof:

         6.2.1    ASSIGNMENT AND SUBLETTING. (a) Except for a Permitted
                  Transfer, not to assign, transfer, mortgage or pledge this
                  Lease or to sublease (which term shall be deemed to include
                  the granting of concessions and licenses and the like) all or
                  any part of the Premises or suffer or permit this Lease or the
                  leasehold estate hereby created or any other rights arising
                  under this Lease (including, without limitation, the use of
                  the parking spaces provided by Landlord pursuant to Section
                  2.1(c) hereof ) to be assigned, transferred or encumbered, in
                  whole or in part, whether voluntarily, involuntarily or by
                  operation of law, or permit the occupancy of the Premises by
                  anyone other than Tenant without the prior written consent of
                  Landlord. Except for a Permitted Transfer, in the event Tenant
                  desires to assign this Lease or sublet any portion or all of
                  the Premises, Tenant shall notify Landlord in writing of
                  Tenant's intent to so assign this Lease or sublet the Premises
                  and the proposed effective date of such subletting or
                  assignment, and shall request in such notification that
                  Landlord consent thereto. Except for transactions which are
                  Permitted Transfers, Landlord may terminate this Lease in the
                  case of a proposed assignment, or suspend this Lease pro tanto
                  for the period and with respect to the space involved in the
                  case of a proposed subletting, by giving written notice of
                  termination or suspension to Tenant within 15 business days
                  after Tenant's notice to Landlord hereunder, with such
                  termination or suspension to be effective as of the effective
                  date of such assignment or subletting. If Landlord does not so
                  terminate or suspend within such 15 business day period,
                  Landlord's consent shall not be unreasonably withheld to an
                  assignment during the initial term or to a subletting during
                  the term of this Lease (including, without limitation, the use
                  by the assignee or subtenant of parking spaces provided by
                  Landlord under Section 2.1(c)) , provided that the following
                  conditions are met:

                  (i)    the proposed assignee or subtenant has a net worth and
                         creditworthiness reasonably acceptable to Landlord;

                  (ii)   the proposed assignee or subtenant is not then, and has
                         not within the 12 months immediately preceding such
                         request been, a tenant in the Building or an entity
                         with whom Landlord is dealing or has dealt regarding
                         the possibility of leasing space in the Building,
                         unless Landlord does not have competing space for lease
                         in the Building;

                  (iii)  Tenant is not in default beyond any applicable grace
                         period under this Lease;

                                       34

<PAGE>



                  (iv)   the assignee or subtenant shall use the Premises only
                         for the Permitted Uses;

                  (v)    with respect to a subletting during an Extension Term
                         of this Lease, after such subletting the initial Tenant
                         named herein shall occupy at least 50% percent of the
                         Rentable Area of the Premises.

                  Tenant shall furnish Landlord with any information reasonably
                  requested by Landlord to enable Landlord to determine whether
                  the proposed assignment or subletting complies with the
                  requirements contained herein, including without limitation,
                  financial statements relating to the proposed assignee or
                  subtenant.

                  (b) Notwithstanding Section 6.2.1(a), if the aggregate amount
                  of space sublet by Tenant previously and taking into account
                  the currently proposed sublease will be less than 30% of the
                  Premises, then Landlord shall not have the right under Section
                  6.2.1(a) to suspend this Lease for the period and with respect
                  to the proposed space to be sublet except to lease such space
                  to another tenant in the Building. However, any such proposed
                  subletting shall be subject to the other provisions of this
                  Section 6.2.1 (including, without limitation, the requirement
                  for Landlord's consent in accordance with and subject to the
                  provisions of Section 6.2.1(a)), except that the proposed
                  subtenant or assignee may then be, or may have been during the
                  immediately preceding 12 months, a tenant in the Building,
                  notwithstanding anything to the contrary contained in Section
                  6.2.1(a)(ii).

                  (c) Tenant shall, as additional rent, reimburse Landlord
                  promptly for Landlord's reasonable legal expenses incurred in
                  connection with any request by Tenant for such consent. If
                  Landlord consents thereto, no such subletting or assignment
                  shall in any way impair the continuing primary liability of
                  Tenant hereunder, and no consent to any subletting or
                  assignment in a particular instance shall be deemed to be a
                  waiver of the obligation to obtain the Landlord's written
                  approval in the case of any other subletting or assignment. If
                  Tenant has not entered into an assignment or sublease within
                  90 days after Landlord's election not to terminate or suspend
                  the term hereof pursuant to Section 6.2.1(a) above, then
                  Landlord shall again have the right to terminate the term in
                  the case of a proposed assignment, or suspend this Lease pro
                  tanto for the period and with respect to the space involved in
                  the case of a proposed subletting in accordance with Section
                  6.2.1(a) as if Landlord's prior election not to do so had not
                  been made.

                  (d) If for any assignment or sublease consented to by Landlord
                  hereunder Tenant receives rent or other consideration, either
                  initially or over the term of the assignment or sublease, in
                  excess of the rent called for hereunder, or in case of
                  sublease of part, in excess of such rent fairly allocable to
                  the part, after appropriate adjustments to assure that all
                  other payments called for hereunder are appropriately taken
                  into account and after deduction for reasonable expenses of

                                       35
<PAGE>

                  Tenant in connection with, and amortized over the term of, the
                  assignment or sublease (including, without limitation,
                  reasonable attorneys' fees, brokerage commissions, tenant
                  improvements and rent concessions in lieu of tenant
                  improvements), to pay to Landlord as additional rent 50%
                  percent of the excess of each such payment of rent or other
                  consideration received by Tenant promptly after its receipt.

                  (e) If, at any time during the term of this Lease, there is a
                  transfer of a controlling interest in the stock, membership or
                  general partnership interests of Tenant, Tenant shall so
                  notify Landlord and such transfer shall not be deemed to be an
                  assignment of this Lease which shall be subject to the
                  provisions of this Section 6.2.1 unless Tenant's Market Value
                  of Equity is reduced below an amount equal to the lesser of
                  (1) Tenant's Market Value of Equity immediately prior to such
                  transfer, or (2) $20,000,000. "Tenant's Market Value of
                  Equity" shall be defined as the product of the number of
                  outstanding shares of publicly traded stock of Tenant on the
                  date in question, multiplied by the closing price for shares
                  of Tenant on such date.

                  (f) Notwithstanding the foregoing, Tenant shall have the right
                  to do the following (a "Permitted Transfer") without
                  Landlord's consent or right to terminate or suspend this Lease
                  under Section 6.2.1(a) or share in any excess proceeds thereof
                  under Section 6.2.1(d):

                  (1) assign this Lease or sublet all or any part of the
                      Premises to any entity ("Tenant Affiliate") which
                      controls, is controlled by or under common control with
                      Tenant ("control" being defined as ownership of more than
                      50% of the beneficial interest of the entity in question)
                      , provided that (a) Tenant shall give Landlord at least 5
                      business days prior notice thereof, together with a copy
                      of the assignment or sublease instrument, and (b) the
                      Tenant Affiliate enters into an agreement with Landlord in
                      which it agrees to assume, perform and be bound by all of
                      the obligations of Tenant under this Lease with regard to
                      the space involved in the transaction in question; or

                  (2) assign or transfer its entire interest in this Lease to
                      any "Tenant Successor" being defined as: (a) a corporation
                      into which or with which Tenant is merged or consolidated,
                      or (b) a corporation, partnership or other business entity
                      acquiring this Lease and all or substantially all of the
                      other property and assets of Tenant, or (c) any successor
                      to any Tenant Successor which becomes such by either of
                      the methods described in (a) or (b) above or otherwise,
                      provided that in all cases ((a), (b) and (c)) the Tenant
                      Successor (1) enters into an agreement with Landlord in
                      which the Tenant Successor agrees to assume, perform and
                      be bound by all of the obligations of Tenant under this
                      Lease, and (2) has a Market Value of Equity after such


                                       36

<PAGE>



                      assignment at least equal to the lesser of (x) Tenant's
                      Market Value of Equity immediately prior to such transfer,
                      or (y) $20,000,000.

         6.2.2    NUISANCE. Not to injure, deface or otherwise harm the Premises
                  or the Property, nor to commit any nuisance; nor permit in the
                  Premises any vending machine (except such as is used for the
                  sale of merchandise to employees of Tenant) or kerosene,
                  gasoline, or inflammable or combustible or explosive fluid or
                  chemical substance other than limited quantities of such
                  materials or substances reasonably necessary for the operation
                  or maintenance of office equipment or limited quantities of
                  cleaning fluids and solvents required in Tenant's normal
                  operations in the Premises (collectively, "Normal Office
                  Chemicals"); nor permit any cooking to such extent as requires
                  special exhaust venting or in violation of the Rules and
                  Regulations set forth in Exhibit G; nor permit the emission of
                  any objectionable noise or odor; nor permit use of any
                  telecommunications or other equipment which interferes with
                  any other Building tenant's use and employment of its demised
                  premises; nor make, allow or suffer any waste; nor make any
                  use of the Premises which is improper, offensive or contrary
                  to any law or ordinance or which will invalidate any of
                  Landlord's insurance or cause any increase above normal
                  insurance premiums on the Building; nor conduct any auction,
                  fire, "going out of business" or bankruptcy sales.

         6.2.3    HAZARDOUS WASTES AND MATERIALS. Subject to Section 6.2.2 above
                  concerning use of Normal Office Chemicals, Not to cause or
                  permit any hazardous or toxic wastes, hazardous or toxic
                  substances or hazardous or toxic materials, (collectively,
                  "Hazardous Materials") to be used, generated, stored or
                  disposed of on, under or above, or transported to or from, the
                  Premises (collectively, "Hazardous Materials Activities")
                  without first receiving Landlord's written consent, which may
                  be withheld for any reason and revoked at any time, if in
                  Landlord's judgment such use shall be harmful or detrimental
                  to any person or property on or about the Building or
                  Property. If Landlord consents to any such Hazardous Materials
                  Activities, Tenant shall conduct them in strict compliance (at
                  Tenant's sole cost and expense) with all applicable laws, and
                  use all necessary and appropriate precautions to prevent any
                  spill, discharge, release or exposure to persons or property.
                  Landlord shall not be liable to Tenant for any loss, cost,
                  expense, claims, damage or liability arising out of any
                  Hazardous Materials Activities by Tenant, Tenant's employees,
                  agents, contractors, licensees, customers or invitees, whether
                  or not consented to by Landlord. Tenant shall indemnify,
                  defend with counsel acceptable to Landlord, and hold Landlord
                  and all Landlord Affiliates harmless from and against any and
                  all loss, costs, expenses, claims, damages or liabilities
                  arising out of: (i) any Hazardous Materials Activities on the
                  Premises, whether or not consented to by Landlord; and (ii)
                  any Hazardous Materials Activities by Tenant, Tenant's
                  employees, agents, contractors, licensees, customers or
                  invitees at the Building. For purposes hereof, "Hazardous
                  Materials" shall include but not be limited to substances
                  defined as "hazardous substances," "toxic substances" or
                  "hazardous wastes" or "oil" in any

                                       37

<PAGE>



                  local, state or federal law, rule, regulation or ordinance
                  (collectively, "Environmental Law(s)"). If Landlord consents
                  to any Hazardous Materials Activities, prior to using, storing
                  or maintaining any Hazardous Materials on or about the
                  Premises (other than Normal Office Chemicals), Tenant shall
                  provide Landlord with a list of the types and quantities
                  thereof, and shall update such list as necessary for continued
                  accuracy. Tenant shall also provide Landlord with a copy of
                  any Hazardous Materials inventory statement for Hazardous
                  Materials other than Normal Office Chemicals and any updates
                  thereof required by any applicable Environmental Laws. If
                  Tenant's activities violate or create a risk of violation of
                  any Environmental Law or cause a spill, discharge, release or
                  exposure to any persons or property, Tenant shall cease such
                  activities immediately upon notice from Landlord. Tenant shall
                  immediately notify Landlord both by telephone and in writing
                  of any spill, discharge, release or exposure of Hazardous
                  Materials in or about the Premises or of any condition in or
                  about the Premises constituting an "imminent hazard" under any
                  Environmental Laws. Landlord, Landlord's representatives and
                  employees may enter the Premise during the term to inspect
                  Tenant's compliance herewith, and may disclose any spill,
                  discharge, release, or exposure or any violation of any
                  Environmental Laws to any governmental agency with
                  jurisdiction.

         6.2.4    FLOOR LOAD; HEAVY EQUIPMENT. Not to place a load upon any
                  floor of the Premises exceeding the floor load per square foot
                  area which Landlord reasonably determines the floor is
                  adequate to carry, and in no event, in excess of that allowed
                  by law. Landlord reserves the right to prescribe the weight
                  and position of all heavy business machines and equipment,
                  including safes, which shall be placed so as to distribute the
                  weight. Business machines and mechanical equipment which cause
                  vibration or noise shall be placed and maintained by Tenant at
                  Tenant's expense in settings sufficient to absorb and prevent
                  vibration, noise and annoyance. Tenant shall not move any
                  safe, heavy machinery, heavy equipment, freight or fixtures
                  into or out of the Premises except in such manner and at such
                  time as Landlord shall in each instance authorize.

         6.2.5    INSTALLATION, ALTERATIONS OR ADDITIONS. (a) Not to make any
                  installations, alterations or additions in, to or on the
                  Premises nor to permit the making of any holes in the walls,
                  partitions, ceilings or floors (other than to hang artwork and
                  the like) nor the installation or modification of any locks or
                  security devices without on each occasion obtaining the prior
                  written consent of Landlord (which shall not be unreasonably
                  withheld, conditioned or delayed), and then only pursuant to
                  plans and specifications reasonably approved by Landlord in
                  advance in each instance and with contractors reasonably
                  approved by Landlord whose labor will work without
                  interference with other labor working on the Premises or the
                  Building. Any plans submitted for Landlord's approval
                  hereunder shall be deemed approved if Landlord does not
                  request more information or specify its reasonable objections
                  thereto in writing to Tenant within 10 business days after
                  submission. Tenant shall pay promptly when due the entire cost
                  of any work to

                                       38

<PAGE>



                  the Premises undertaken by Tenant so that the Premises shall
                  at all times be free of liens for labor and materials, and at
                  Landlord's request if the work costs over $100,000 Tenant
                  shall furnish to Landlord a bond or other security acceptable
                  to Landlord assuring that any work commenced by Tenant will be
                  completed in accordance with the plans and specifications
                  theretofore approved by Landlord and assuring that the
                  Premises will remain free of any mechanics' lien or other
                  encumbrance arising out of such work. All such work shall be
                  done in a good and workmanlike manner employing materials of
                  good quality and so as to conform with all applicable zoning,
                  building, fire, health and other codes, regulations,
                  ordinances and laws. Tenant shall save Landlord and all
                  Landlord Affiliates harmless and indemnified from all injury,
                  loss, claims or damage to any person or property occasioned by
                  or growing out of such work.

                  (b) Before Tenant begins any work, Tenant shall (i) secure all
                  licenses and permits necessary therefor at Tenant's sole
                  expense, (ii) deliver to Landlord a statement of the names of
                  all its contractors and subcontractors and the estimated cost
                  of all labor and material to be furnished by them and (iii)
                  cause each contractor to carry (A) workers' compensation
                  insurance in statutory amounts and employer's liability
                  insurance with limits not less than $500,000 per accident
                  covering all the contractor's and subcontractor's employees,
                  (B) commercial general liability insurance, including
                  completed operations coverage for a period of 2 years beyond
                  completion of the work that the contractor/subcontractor
                  performs with such limits as Landlord may reasonably require,
                  but in no event less than $2,000,000 per occurrence, and (C)
                  automobile liability insurance with such limits as Landlord
                  may reasonably require, but in no event less than $2,000,000
                  combined single limit per accident. All such insurance (i) is
                  to be written by companies reasonably approved by Landlord,
                  (ii) shall name Landlord, all Landlord Affiliates requested by
                  Landlord and Tenant as additional insureds, as their
                  respective interests may appear, as well as their respective
                  contractors and subcontractors, (iii) shall contain a waiver
                  of subrogation provision in favor of Landlord and all such
                  Landlord Affiliates, and (iv) shall be primary coverage as to
                  any other coverage maintained by any insured other than
                  Tenant). Tenant shall deliver to Landlord certificates of all
                  such insurance before Tenant begins any work. Tenant agrees to
                  promptly pay when due the entire cost of any work done in the
                  Premises by Tenant, its agents, employees or contractors, and
                  within 5 business days upon receipt of notice of the same to
                  discharge or bond off any such liens which may attach to the
                  Premises by reason of such work.

                  (c) Landlord may inspect the work in progress at reasonable
                  times, provided, however, Landlord shall, except in case of
                  emergency, (i) give Tenant reasonable prior notice of such
                  inspections and (ii) conduct such inspections so as to
                  minimize interference with the construction work of Tenant.
                  All work shall be done so as to minimize unreasonable
                  interference with other tenants or lawful occupants of the
                  Building and with Landlord's operation of the Building or
                  other construction work being done by Landlord.

                                       39

<PAGE>

                  (d) At Landlord's request, Tenant shall, promptly after such
                  work is completed, provide Landlord with a full set of as
                  built plans for the portions of the Premises affected by such
                  work, unless such work did not change anything that would be
                  shown on as built plans.

         6.2.6    ABANDONMENT. Not to abandon the Premises during the term.

         6.2.7    SIGNS. Not without Landlord's prior written approval, to paint
                  or place any signs or place any curtains, blinds, shades,
                  awnings, aerials, or the like, visible from outside the
                  Premises. Landlord agrees that Tenant may have its name in the
                  Building directory and Tenant's Office Percentage of the space
                  therein for names of Tenant's personnel, at Landlord's
                  expense. Landlord will also pay up to $1,000 for an
                  identification sign for Tenant on any multi-tenant floor upon
                  which part of the Premises is located that complies with
                  Landlord's design standards therefor.


                                    ARTICLE 7

                               CASUALTY OR TAKING

7.1      TERMINATION. In the event that the Premises or the Building, or any
         material part thereof, shall be taken by any public authority or for
         any public use, or shall be destroyed or damaged by fire or casualty,
         or by the action of any public authority, then this Lease may be
         terminated at the election of Landlord. Such election, which may be
         made notwithstanding the fact that Landlord's entire interest may have
         been divested, shall be made by the giving of notice by Landlord to
         Tenant within 60 days after the date of the taking or casualty.

7.2      RESTORATION. If Landlord does not elect to so terminate within 60 days
         after the date of the taking or casualty, this Lease shall continue in
         force and a just proportion of the rent reserved, according to the
         nature and extent of the damages sustained by the Premises, shall be
         suspended or abated until the Premises, or what may remain thereof,
         shall be put by Landlord in proper condition for use, which Landlord
         covenants to do with reasonable diligence to the extent permitted by
         the net proceeds of insurance recovered or damages awarded for such
         taking, destruction or damage and subject to zoning and building laws
         or ordinances then in existence (such work being referred to as
         "Landlord's Restoration Work"). "Net proceeds of insurance recovered or
         damages awarded" refers to the gross amount of such insurance or
         damages less the reasonable expenses of Landlord incurred in connection
         with the collection of the same, including without limitation, fees and
         expenses for legal and appraisal services. If Landlord's Restoration
         Work hereunder has not been substantially completed within 9 months
         after the date of damage (which date shall be extended for up to 60
         days of delays resulting from causes set forth in Section 11.5 or and
         the length of any delays resulting from Tenant or any of its agents,
         employees

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         or contractors), then Tenant shall have the right to terminate this
         Lease by giving Landlord written notice of its election to do so within
         30 days after the end of such 11 month period, and if Tenant timely
         gives such notice, this Lease shall terminate 30 days after the date
         thereof unless Landlord's Restoration Work is substantially completed
         within such 30 day period, in which event such termination notice shall
         be void and this Lease shall continue in full force and effect.

7.3      AWARD. Irrespective of the form in which recovery may be had by law,
         all rights to damages or compensation shall belong to Landlord in all
         cases. Tenant hereby grants to Landlord all of Tenant's rights to such
         damages and covenants to deliver such further assignments thereof as
         Landlord may from time to time request. The foregoing shall not apply,
         however, to any separate award for Tenant's personalty and moving
         expenses in the case of a taking.



                                    ARTICLE 8

                                    DEFAULTS

8.1      EVENTS OF DEFAULT. If any of the following occurs:

         (a) Tenant shall default in the payment when due of any Fixed Rent or
         additional rent, and such default shall continue for 10 days after
         notice thereof from Landlord; or

         (b) Tenant shall have previously defaulted more than twice in any 12
         month period in the payment when due of any Fixed Rent or additional
         rent, Tenant defaults in the payment when due of any Fixed Rent or
         additional rent, and such default shall continue for 5 days after
         notice thereof from Landlord; or

         (c) Tenant shall default in the timely performance or observance of any
         of the other covenants contained in this Lease on the Tenant's part to
         be performed or observed and shall fail, within 30 days after notice
         from Landlord of such default, to cure such default or if such default
         is not reasonably susceptible of cure within 30 days, if Tenant shall
         fail to commence to cure within said 30 days after notice of such
         default from Landlord or shall thereafter fail diligently to prosecute
         such cure to completion; or

         (d) the estate hereby created shall be taken on execution, or by other
         process of law; or

         (e) Tenant commences a voluntary case under Title 11 of the United
         States Code as from time to time in effect, or it authorizes, by
         appropriate proceedings of trustees or other governing body the
         commencement of such a voluntary case; or

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<PAGE>

         (f) Tenant files an answer or other pleading admitting or failing to
         deny the material allegations of a petition filed against it commencing
         an involuntary case under said Title 11, or if it seeks, consents to or
         acquiesces in the relief therein provided, or if it fails to controvert
         timely the material allegations of any such petition; or

         (g) there is entered an order for relief in any involuntary case
         commenced under said Title; or

         (h) Tenant seeks relief as a debtor under any applicable law, other
         than said Title 11, of any jurisdiction relating to the liquidation or
         reorganization of debtors or to the modification or alteration of the
         rights of creditors, or by Tenant's consent to or acquiescence in such
         relief; or

         (i) there is entered an order by a court of competent jurisdiction (i)
         finding Tenant to be bankruptcy or insolvent, (ii) ordering or
         approving Tenant's liquidation, reorganization or any modification or
         alteration of the rights of its creditors, or (iii) assuming custody
         of, or appointing a receiver or other custodian for, all or a
         substantial part of Tenant's property; or

         (j) Tenant makes an assignment for the benefit of, or enters into a
         composition with, its creditors, or appoints or consents to the
         appointment of a receiver or other custodian for all or a substantial
         part of its property; or

         (k) Tenant rejects this Lease and a court of competent jurisdiction
         enters an order approving the rejection of the Lease under Title 11 of
         the United States Code as from time to time in effect, or under any
         applicable law, other than said Title 11, of any jurisdiction relating
         to the liquidation or reorganization of debtors or to the modification
         or alteration of the rights of creditors, or by Tenant's consent to or
         acquiescence in such relief;

         then and in any of said cases, Landlord may, to the extent permitted by
         law, immediately or at any time thereafter and with or without demand
         or notice to Tenant, terminate this Lease and enter into and upon the
         Premises, or any part thereof in the name of the whole, and repossess
         the same as of Landlord's former estate, and expel Tenant and those
         claiming through or under Tenant and remove its effects without being
         deemed guilty of any manner of trespass, and without prejudice to any
         remedies which might otherwise be used for arrears of rent and
         preceding breach of covenant.

8.2      REMEDIES. (a) No termination or repossession provided for in Section
         8.1 shall relieve Tenant or any guarantor of the liabilities and
         obligations of Tenant under this Lease, all of which shall survive any
         such termination or repossession. In the event of any such termination
         or repossession, Tenant shall pay to Landlord, at Landlord's election,
         either (i) in advance on the first day of each month, for what would
         have been the entire balance of the term, 1/12th (and a pro rata
         portion thereof for any fraction of a month) of the

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         annual Fixed Rent, additional rent and all other amounts for which
         Tenant is obligated hereunder, less, in each case, the actual net
         receipts by Landlord by reason of any re-letting of the Premises after
         deducting Landlord's reasonable expenses in connection with such
         re-letting, including, without limitation, removal, storage and repair
         costs and reasonable brokers' and attorneys' fees, or (ii) upon demand
         and at the option of Landlord at any time thereafter, the present value
         computed at a capitalization rate based upon the Prime Rate, of the
         amount by which the payments of Fixed Rent and additional rent
         reasonably estimated to be payable for the balance of the term would
         exceed the payments reasonably estimated by Landlord to be the fair
         rental value of the Premises on the terms and conditions of this Lease
         over such period, determined as of such date.

         (b) Landlord may (i) re-let the Premises or any part or parts thereof,
         for a term or terms which may at Landlord's option be equal to or less
         than or exceed the period which would otherwise have constituted the
         balance of the term and may grant such concessions and free rent as
         Landlord in its sole discretion considers advisable or necessary to
         re-let the same, and (ii) make such alterations, repairs and
         decorations to the Premises as Landlord in its sole discretion
         considers advisable or necessary to re-let the same, and no action of
         Landlord in accordance with the foregoing or failure to re-let or to
         collect rent under re-letting shall operate or be construed to release
         or reduce Tenant's liability as aforesaid.

         (c) Nothing contained in this Lease shall limit or prejudice the right
         of Landlord to prove for and obtain in proceedings for bankruptcy,
         insolvency or like proceedings by reason of the termination of this
         Lease, an amount equal to the maximum allowed by any statute or rule of
         law in effect at the time when, and governing the proceedings in which,
         the damages are to be proved, whether or not the amount be greater,
         equal to, or less than the amount of the loss or damages referred to
         above.

8.3      REMEDIES CUMULATIVE. Any and all rights and remedies which either party
         may have under this Lease, and at law and equity, shall be cumulative
         and shall not be deemed inconsistent with each other, and any two or
         more of all such rights and remedies may be exercised at the same time
         insofar as permitted by law, except for any which are expressly
         designated as exclusive rights or remedies.

8.4      LANDLORD'S RIGHT TO CURE DEFAULTS. Landlord may, but shall not be
         obligated to, cure, at any time, without notice, any default by Tenant
         under this Lease; and whenever Landlord so elects, all costs and
         expenses incurred by Landlord, including reasonable attorneys' fees, in
         curing a default shall be paid, as additional rent, by Tenant to
         Landlord on demand, together with interest thereon at the Default Rate
         from the date of payment by Landlord to the date of payment by Tenant.

8.5      EFFECT OF WAIVERS OF DEFAULT. Any consent or permission by either party
         to any act or omission which otherwise would be a breach of any
         covenant or condition herein, shall not in any way be held or construed
         (unless expressly so declared) to operate so as to

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         impair the continuing obligation of any covenant or condition herein,
         or otherwise, except as to the specific instance, operate to permit
         similar acts or omissions.

8.6      NO WAIVER, ETC. The failure of either party to seek redress for
         violation of, or to insist upon the strict performance of, any covenant
         or condition of this Lease shall not be deemed a waiver of such
         violation nor prevent a subsequent act, which would have originally
         constituted a violation, from having all the force and effect of an
         original violation. The receipt by Landlord of rent with knowledge of
         the breach of any covenant of this Lease shall not be deemed to have
         been a waiver of such breach by Landlord. No consent or waiver, express
         or implied, by either party to or of any breach of any agreement or
         duty shall be construed as a waiver or consent to or of any other
         breach of the same or any other agreement or duty.

8.7      NO ACCORD AND SATISFACTION. No acceptance by Landlord of a lesser sum
         than the Fixed Rent, additional rent or any other charge then due shall
         be deemed to be other than on account of the earliest installment of
         such rent or charge due, nor shall any endorsement or statement on any
         check or any letter accompanying any check or payment as rent or other
         charge be deemed an accord and satisfaction, and Landlord may accept
         such check or payment without prejudice to Landlord's right to recover
         the balance of such installment or pursue any other remedy in this
         Lease provided.

                                    ARTICLE 9

                     RIGHTS OF MORTGAGEES AND GROUND LESSORS

9.1      RIGHTS OF MORTGAGEES AND GROUND LESSORS. (a) This Lease, and all rights
         of Tenant hereunder, are and shall be subject and subordinate to any
         Superior Lease and all renewals, extensions, modifications and
         replacements thereof, and to all Superior Mortgages whether or not any
         such Superior Mortgage shall also cover other lands and/or buildings,
         to each and every advance made or hereafter to be made under such
         Superior Mortgages, and to all renewals, modifications, replacements
         and extensions of such Superior Leases and such Superior Mortgages and
         all consolidations of such Superior Mortgages, provided that Landlord
         shall deliver to Tenant an agreement ("Non-Disturbance Agreement") of
         each such Superior Lessor or Superior Mortgagee in the customary form
         used by such Superior Lessor or Superior Mortgagee to the effect that,
         subject to the conditions set forth in clauses (a) - (g) of the
         following paragraph, Tenant's rights under this Lease shall not be
         disturbed by such Superior Lessor or Superior Mortgagee, so long as
         there shall exist no event of default hereunder as referred to in
         Section 8.1 hereof. This Section shall be self-operative and no further
         instrument of subordination shall be required. In confirmation of such
         subordination, Tenant shall promptly execute, acknowledge and deliver
         any instrument that Landlord, any Superior Lessor or any Superior
         Mortgagee or any of their respective successors in interest may
         reasonably require to evidence such subordination. Any lease to which
         this Lease is, at

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         the time referred to, subject and subordinate is herein called
         "Superior Lease" and the lessor of a Superior Lease or its successor in
         interest, at the time referred to, is herein called "Superior Lessor";
         and any mortgage to which this Lease is, at the time referred to,
         subject and subordinate, is herein called "Superior Mortgage" and the
         holder of a Superior Mortgage is herein called "Superior Mortgagee".
         The parties acknowledge that Superior Leases as of the date hereof
         consist of (i) a certain East Office Ground Lease (the "Massport
         Lease") between Massachusetts Port Authority ("Massport"), as landlord,
         and 121A Owner, as tenant, dated as of July 13, 1998, and (ii) a
         certain East Office Operating Sublease between 121A Owner, as landlord,
         and Landlord, as tenant, dated as of July 13, 1998.

         (b) If any Superior Lessor or Superior Mortgagee or the nominee or
         designee of any Superior Lessor or Superior Mortgagee shall succeed to
         the rights of Landlord under this Lease, whether through possession or
         foreclosure action or delivery of a new lease or deed, or otherwise,
         then at the request of such party so succeeding to Landlord's rights
         (herein called "Successor Landlord") and upon such Successor Landlord's
         written agreement to accept Tenant's attornment, Tenant shall attorn to
         and recognize such Successor Landlord as Tenant's landlord under this
         Lease and shall promptly execute and deliver any instrument that such
         Successor Landlord may reasonably request to evidence such attornment.
         Upon such attornment, this Lease shall continue in full force and
         effect as a direct lease between the Successor Landlord and Tenant upon
         all of the terms, conditions and covenants as are set forth in this
         Lease, except that the Successor Landlord (unless formerly the landlord
         under this Lease or its nominee or designee) shall not be (a) liable in
         any way to Tenant for any act or omission, neglect or default on the
         part of Landlord under this Lease, (b) responsible for any monies owing
         by or on deposit with Landlord to the credit of Tenant other than the
         Security Deposit and rent for the balance of the current month if paid
         in advance by Tenant, (c) subject to any counterclaim or setoff which
         theretofore accrued to Tenant against Landlord, (d) bound by any
         modification of this Lease subsequent to such Superior Lease or
         Mortgage, or by any previous prepayment of Annual Fixed Rent or
         additional rent for more than 1 month, which was not approved in
         writing by the Superior Landlord or the Superior Mortgagee, (e) liable
         to the Tenant beyond the Successor Landlord's interest in the Property
         and the rents, income, receipts, revenues, issues and profits issuing
         from the Property, (f) responsible for the performance of any work to
         be done by the Landlord under this Lease to render the Premises ready
         for occupancy by the Tenant, but shall be subject to the provisions of
         Sections 3.1(b) and 3.1(c), or (g) required to remove any person
         occupying the Premises or any part thereof, except if such person
         claims by, through or under the Successor Landlord.

9.2      MODIFICATIONS. If any Superior Lessor or Superior Mortgagee shall
         reasonably require any modification(s) of this Lease, Tenant shall, at
         Landlord's request, promptly execute and deliver to Landlord such
         instruments effecting such modification(s) as Landlord shall require,
         provided that such modification(s) do not affect the rent payable
         hereunder and do not adversely affect in any material respect any of
         Tenant's rights or impose any new obligations under this Lease. In
         addition, and notwithstanding Section 9.1 to the contrary, Landlord or
         any Superior Lessor or Superior Mortgagee may, at its option, make this
         Lease superior to any such Superior Mortgage or Superior Lease by
         giving Tenant 10 days prior written notice of such election and no
         other documentation shall be necessary to effect such change.

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                                   ARTICLE 10

                         APPRAISAL OF FAIR RENTAL VALUE

10.1     DISPUTE AS TO FAIR RENTAL VALUE. In the event that Tenant disputes the
         amount claimed by Landlord as Fair Rental Value of the Premises
         pursuant to Section 2.4 and such dispute cannot be resolved by mutual
         agreement on or before the date 13 months prior to the commencement of
         the Extension Term, Tenant shall have the right to submit the dispute
         to the appraisal process hereinafter set forth. The amount of Fair
         Rental Value determined pursuant to such appraisal process shall be
         final and binding between the parties. The appraisal process shall be
         conducted as follows:

         10.1.1   APPOINTMENT OF APPRAISERS. Tenant shall make demand for
                  appraisal in writing within 20 business days after service of
                  Landlord's determination of Fair Rental Value given under
                  Section 2.4 specifying therein the name and address of the
                  person to act as the appraiser on its behalf. The appraiser
                  shall be a real estate appraiser with at least ten years'
                  experience in the field and a qualified member of the American
                  Institute of Real Estate Appraisers, or any successor of such
                  Institute (or if such organization or successor shall not
                  longer be in existence, a recognized national association or
                  institute of land appraisers) familiar with the fair market
                  rent of first-class commercial office space in Boston,
                  Massachusetts. Failure on the part of Tenant to make a timely
                  and proper demand for such appraisal shall constitute a waiver
                  of the right thereto. Within 10 business days after the
                  service of the demand for appraisal, Landlord shall give
                  notice to Tenant, specifying the name and address of the
                  person designated by Landlord to act as appraiser on its
                  behalf who shall be similarly qualified. If Landlord fails to
                  notify Tenant of the appointment of its appraiser within or by
                  the time above specified, then Tenant shall thereafter send a
                  second notice to Landlord indicating such failure and
                  requesting Landlord to appoint such an appraiser. If Landlord
                  fails to notify Tenant of the appointment of its appraiser
                  within 5 business days after the giving of such notice by
                  Tenant then the appraiser appointed by Tenant shall be the
                  sole appraiser to determine the issue.

         10.1.2   DECISION BY TWO APPRAISERS. In the event that 2 appraisers are
                  chosen pursuant to paragraph (a) above, the appraisers so
                  chosen shall meet within 10 business days after the second
                  appraiser is appointed and, if within 10 business days after
                  such first meeting the two appraisers shall be unable to agree
                  upon a determination of Fair Rental Value, they shall appoint
                  a third appraiser, who shall be a competent and impartial
                  person with the same minimum qualifications and experience as
                  is required of the first two appraisers. In the event they are
                  unable to agree upon such appointment within 5 business days
                  after expiration of said 10 day period, the third appraiser
                  shall be selected by the parties themselves, if they can agree
                  thereon, within a further period of 10 business days. If the
                  parties do not so agree, then either party, on behalf of both,
                  may request appointment of such a qualified person

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<PAGE>



                  by an officer of the American Arbitration Association in
                  Boston, Massachusetts. The 3 appraisers shall decide the
                  dispute, if it has not previously been resolved, by following
                  the procedure set forth below.

         10.1.3   DECISION BY THREE APPRAISERS. Where the issue cannot be
                  resolved by agreement the two appraisers selected by Landlord
                  and Tenant or settlement between the parties during the course
                  of the appraisal process, the issue shall be resolved by the
                  three appraisers in accordance with the following procedure.
                  Within 20 days after the third appraiser has been selected,
                  each appraiser shall state in writing his determination of the
                  Fair Rental Value, supported by the reasons therefor, with
                  counterpart copies to each party. The appraisers shall arrange
                  for a simultaneous exchange of such proposed determinations.
                  The Fair Rental Value shall be the mean of the three
                  appraisals; provided, however, if an appraisal deviates from
                  the mean by more than 10%, such deviant appraisal shall be
                  discarded and Fair Rental Value shall be, if there is one
                  deviant appraisal, the mean of the two appraisals remaining,
                  or, if there are two deviant appraisals, the one appraisal
                  remaining.

10.2     BINDING EFFECT; COSTS. All such determinations of Fair Rental Value
         shall be final and binding upon the parties. The provision for
         determination by appraisal shall be specifically enforceable to the
         extent such remedies are available under the applicable law, and any
         determination hereunder shall be final and binding upon the parties
         hereto, and either party shall have the right to enter judgment
         thereon, unless otherwise provided by applicable law. If a
         determination of Fair Rental Value is to be made pursuant to this
         Article 10, Landlord and Tenant shall each pay for the fees and
         disbursements of any appraiser appointed by it and shall share equally
         in the fees and expenses of any third appraiser.

                                   ARTICLE 11

                            MISCELLANEOUS PROVISIONS

11.1     NOTICES FROM ONE PARTY TO THE OTHER. All notices required or permitted
         hereunder shall be in writing and addressed, if to the Tenant, at the
         Original Notice Address of Tenant or after the Fixed Rent Commencement
         Date for the Initial Premises at the Premises or such other address as
         Tenant shall have last designated by notice in writing to Landlord and,
         if to Landlord, at the Original Notice Address of Landlord or such
         other address as Landlord shall have last designated by notice in
         writing to Tenant. Any notice shall be sent to such address by
         registered or certified mail, return receipt requested, postage
         prepaid, or by nationally recognized courier, charges prepaid, or by
         hand and shall be effective when received or when tendered delivery is
         refused.

11.2     QUIET ENJOYMENT. Landlord agrees that upon Tenant's paying the rent and
         performing and observing the agreements, conditions and other
         provisions on its part to be performed and observed, Tenant shall and
         may peaceably and quietly have, hold and enjoy the Premises during the
         term hereof without any manner of hindrance or molestation from

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<PAGE>



         Landlord or anyone claiming under Landlord, subject, however, to the
         terms of this Lease.

11.3     LEASE NOT TO BE RECORDED. Tenant agrees that it will not record this
         Lease. Both parties shall, upon the request of either, execute and
         deliver a notice or short form of this Lease in such form, if any, as
         may be permitted by applicable statute.

11.4     LIMITATION OF LANDLORD'S LIABILITY. The term "Landlord" as used in this
         Lease, so far as covenants or obligations to be performed by Landlord
         are concerned, shall be limited to mean and include only the owner or
         owners at the time in question of the Property, and in the event of any
         transfer or transfers of title to the Property, the Landlord (and in
         case of any subsequent transfers or conveyances, the then grantor)
         shall be concurrently freed and relieved from and after the date of
         such transfer or conveyance, without any further instrument or
         agreement of all liability as respects the performance of any covenants
         or obligations on the part of the Landlord contained in this Lease
         thereafter to be performed, it being intended hereby that the covenants
         and obligations contained in this Lease on the part of Landlord, shall,
         subject as aforesaid, be binding on the Landlord, its successors and
         assigns, only during and in respect of their respective successive
         periods of ownership of said leasehold interest or fee, as the case may
         be. Tenant, its successors and assigns, shall not assert nor seek to
         enforce any claim for breach of this Lease against any of Landlord's
         assets other than Landlord's interest in the Property and in the rents,
         issues and profits thereof, and Tenant agrees to look solely to such
         interest for the satisfaction of any liability or claim against
         Landlord under this Lease, it being specifically agreed that in no
         event whatsoever shall Landlord (which term shall include, without
         limitation, any general or limited partner, trustees, beneficiaries,
         officers, directors, or stockholders of Landlord) ever be personally
         liable for any such liability.

11.5     ACTS OF GOD. In any case where either party hereto is required to do
         any act, delays caused by or resulting from Acts of God, war, civil
         commotion, fire, flood or other casualty, labor difficulties, shortages
         of labor, materials or equipment, government regulations, unusually
         severe weather, or other causes beyond such party's reasonable control
         shall not be counted in determining the time during which work shall be
         completed, whether such time be designated by a fixed date, a fixed
         time or a "reasonable time," and such time shall be deemed to be
         extended by the period of such delay.

11.6     LANDLORD'S DEFAULT. Landlord shall not be deemed to be in default in
         the performance of any of its obligations hereunder unless it shall
         fail to perform such obligations and such failure shall continue for a
         period of 30 days or such additional time as is reasonably required to
         correct any such default after written notice has been given by Tenant
         to Landlord specifying the nature of Landlord's alleged default.
         Landlord shall not be liable in any event for incidental or
         consequential damages to Tenant by reason of Landlord's default,
         whether or not notice is given. Except as expressly set forth herein,
         Tenant shall have no right to terminate this Lease for any default by
         Landlord hereunder and no right, for any such default, to offset or
         counterclaim against any rent due hereunder.

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11.7     BROKERAGE. Each party warrants and represents that it has dealt with no
         broker in connection with the consummation of this Lease, other than
         the Broker (whose commission shall be paid by Landlord pursuant to a
         separate agreement if, as and when this Lease is fully executed and
         delivered and not otherwise), and each party shall defend, indemnify
         and hold harmless the other against any and all liability for breach of
         such warranty and representation.

11.8     APPLICABLE LAW AND CONSTRUCTION. This Lease shall be governed by and
         construed in accordance with the laws of the Commonwealth of
         Massachusetts and, if any provisions of this Lease shall to any extent
         be invalid, the remainder of this Lease shall not be affected thereby.
         There are no oral or written agreements between Landlord and Tenant
         affecting this Lease. This Lease may be amended, and the provisions
         hereof may be waived or modified, only by instruments in writing
         executed by Landlord and Tenant. The titles of the several Articles and
         Sections contained herein are for convenience only and shall not be
         considered in construing this Lease. Unless repugnant to the context,
         the words "Landlord" and "Tenant" appearing in this Lease shall be
         construed to mean those named above and their respective heirs,
         executors, administrators, successors and assigns, and those claiming
         through or under them respectively. If there be more than one tenant,
         the obligations imposed by this Lease upon Tenant shall be joint and
         several.

11.9     LITIGATION EXPENSES. In any litigation between the parties regarding
         this Lease, the losing party shall pay to the prevailing party all
         reasonable expenses and court costs including attorney's fees incurred
         by the prevailing party. A party shall be considered the prevailing
         party if:

         (i) it initiated the litigation and substantially obtains the relief
             sought, either by entry of a judgment or the other party's
             voluntary action before trial or judgment;

        (ii) it did not initiate the litigation and the other party withdraws
             its action without substantially obtaining the relief it sought;
             or

       (iii) it did not initiate the litigation and judgment is entered in
             favor of either party, but without substantially granting the
             relief sought by the initiating party.

11.10    ROOF SPACE. (a) Tenant shall have the right to use an area of the roof
         of the Building designated by Landlord (the "Roof Space") for the
         purpose of installing (in accordance with the terms and conditions of
         this Lease), operating and maintaining a satellite dish antenna, not
         larger than 18 inches in diameter, and the necessary equipment related
         thereto for Tenant's own use (collectively the "Communications
         Equipment"). Tenant shall pay Landlord annual rent for the Roof Space
         at the rate of $300.00 per month, payable at the same time and in the
         same manner as the Annual Fixed Rent for the Premises, and all of the
         other provisions of this Lease shall apply to the Roof Space as if it
         were part of the Premises.

                                       49

<PAGE>

         (b) Tenant's right to install the Communications Equipment shall be
         subject to the reasonable approval rights of Landlord and Landlord's
         architect with respect to the plans and specifications for the
         Communications Equipment, including, without limitation, the size,
         height and dimensions of the Communications Equipment, the manner in
         which the Communications Equipment is attached to the roof of the
         Building and the manner in which any cables are run to and from
         Premises and the Communications Equipment. Tenant shall be solely
         responsible for obtaining all necessary governmental and regulatory
         approvals and for the cost of installing, operating, maintaining and
         removing of the Communications Equipment.

         (c) Landlord agrees that Tenant, upon reasonable prior notice to
         Landlord, shall have access to the Roof Space for the purpose of
         installing, maintaining, repairing and removing the Communications
         Equipment, provided that, in the event of an emergency, Landlord will
         use reasonable efforts to provide Tenant with immediate access to the
         Roof Space. It is agreed, however, that only authorized engineers,
         employees or properly authorized contractors of Tenant, FCC inspectors
         or persons under their direct supervision will be permitted to have
         access to the Roof Space. Tenant further agrees to exercise firm
         control over the people requiring access to the Roof Space in order to
         keep to a minimum the number of people having access to the Roof Space
         and the frequency of their visits.

         (d) Tenant shall be responsible for assuring that the installation,
         maintenance, operation and removal of the Communications Equipment will
         in no way damage the Building or roof thereof, or interfere with the
         use of the Building and roof by Landlord or any other tenants. Tenant
         agrees to be responsible for any damage caused to the roof or any other
         part of the Building, which may be caused by Tenant or any of its
         agents or representatives.

         (e) Tenant agrees to install and operate the Communications Equipment
         in a manner which will not cause material interference to Landlord or
         other tenants of the Building. For purposes hereof, interference from
         the operation of the Communications Equipment shall be deemed to be
         material if it reduces the operating efficiency or utility of any
         equipment or if it adversely affects the purity of any frequency or
         signal then used by Landlord or any tenant of the Building for
         transmission or receiving purposes. In the event the Communications
         Equipment causes such material interference, Tenant shall change the
         frequency on which it transmits and/or receives and take any other
         steps necessary to eliminate the interference. If said interference
         cannot be eliminated within a reasonable period of time, in the
         judgment of Landlord, the Tenant agrees to remove the portion of the
         Communications Equipment from the Roof Space that is causing such
         interference and Tenant's right to use the Roof Space for such portion
         of the Communications Equipment shall then terminate without further
         obligation on either party, other than Tenant's obligation to remove
         such Communications Equipment and repair any damages as a result
         thereof.

                                       50

<PAGE>



         (f) All installations and operations in connection with this Lease by
         Tenant shall meet with all applicable rules and regulations of the
         Federal Communications Commission ("FCC"), Federal Aviation
         Administration ("FAA") and all applicable codes and regulations of the
         city, county and state concerned. Under this Lease, the Landlord
         assumes no responsibility for the licensing, operation and/or
         maintenance of Tenant's equipment. Tenant has the responsibility of
         carrying out the terms of its FCC license in all respects.

         (g) Tenant shall be responsible for the cost of installation,
         operation, cleanliness, maintenance and removal of the Communications
         Equipment and appurtenances, all of which shall remain the personal
         property of Tenant, and shall be removed by Tenant at its own expense
         at the termination of this Lease. Tenant shall repair any damage caused
         by such removal, including the patching of any holes to match, as
         closely as possible, the color surrounding the area where the equipment
         and appurtenances were attached. Such maintenance and operation shall
         be performed in a manner to avoid any interference with any other
         tenants or Landlord. Tenant agrees to maintain all of Tenant's
         equipment placed on or about the roof in proper operating condition and
         maintain same in satisfactory condition as to appearance and safety.
         Tenant agrees that at all times during the term of this Lease, it will
         keep the Roof Space free of all trash or waste materials by Tenant.

         (h) In light of the specialized nature of the Communications Equipment,
         Tenant shall be permitted to utilize the services of its choice for
         installation, removal and repair of the Communications Equipment.
         Notwithstanding the foregoing, Tenant must provide Landlord with prior
         notice of any such installation, removal or repair and coordinate such
         work with Landlord in order to avoid voiding or otherwise adversely
         effecting any warranties granted to Landlord with respect to the roof.
         If necessary, Tenant, at its sole cost and expense, shall retain any
         contractor having a then existing warranty in effect on the roof to
         perform such work (to the extent that it involves the roof), or, at
         Tenant's option, to perform such work in conjunction with Tenant's
         contractor. In the event Landlord contemplates roof repairs that
         require temporary removal or relocation of the Communications
         Equipment, or which may result in an interruption of the Tenant's
         telecommunication service, Landlord shall formally notify Tenant at
         least ten (10) days in advance prior to the commencement of such
         contemplated work in order to allow Tenant to make other arrangements
         for such services, provided that, in the event of an emergency,
         Landlord shall not be required to give Tenant ten (10) days notice but,
         in good faith, shall give Tenant as much notice as is reasonably
         possible considering the nature of the emergency. In addition, if the
         roof repairs are not of an emergency nature and Tenant reasonably
         requires more than ten (10) days in which to make alternative service
         arrangements, Landlord will work together in good faith with Tenant to
         agree upon an arrangement that allows Landlord to perform such roof
         repairs on a timely basis without additional cost and allows Tenant an
         adequate amount of time to make alternative service arrangements.

                                       51

<PAGE>



                                   ARTICLE 12

                                SECURITY DEPOSIT



12.1     INITIAL SECURITY DEPOSIT. Concurrently with Tenant's execution of this
         Lease Tenant shall wire transfer to Landlord, in accordance with the
         wiring instructions set forth in Exhibit K attached hereto, funds in
         the amount of the Security Deposit Amount set forth in Section 1.1 as
         security for the full and punctual performance by Tenant of all of the
         terms of this Lease. Landlord shall deposit such funds in an interest
         bearing money market account in a financial institution selected by
         Landlord, with interest to be added to such account (the funds and
         interest in such account being referred to as the "Security Deposit").
         In the event Tenant defaults in the performance of any of the terms of
         this Lease beyond any applicable cure period, including the payment of
         rent, Landlord may use, apply or retain the whole or any part of the
         Security Deposit to the extent required for the payment of any rent or
         for any sum which Landlord may expend or may be required to expend by
         reason of Tenant's default of any of the terms of this Lease, including
         any damages or deficiency in the re-letting of the Premises, whether
         accruing before or after summary proceedings or other re-entry by
         Landlord. In the case of every such use, application or retention,
         Tenant shall, on demand, pay to Landlord the sum which when added to
         the Security Deposit then held by Landlord (if any) will cause the
         Security Deposit held by Landlord to equal the applicable Security
         Deposit Amount. If Tenant shall fully and punctually comply with all of
         the terms of this Lease, the Security Deposit, together with any
         accrued interest thereon, shall be returned to Tenant after the
         termination of this Lease and delivery of exclusive possession of the
         Premises to Landlord. In the event of a sale or lease of the building,
         Landlord shall have the right to transfer the security to the buyer or
         lessee and Landlord shall ipso facto be released by Tenant from all
         liability for the return of such security; and Tenant agrees to look
         solely to the new landlord for the return of the Security Deposit; and
         it is agreed that the provisions hereof shall apply to every transfer
         or assignment made of the Security Deposit to a new landlord. Tenant
         shall not assign or encumber or attempt to assign or encumber the
         monies deposited herein as security and neither Landlord nor its
         successors or assigns shall be bound by any such assignment,
         encumbrance or attempted assignment or encumbrance.

12.2     REDUCTION SCHEDULE. Provided that Tenant is not in default of any of
         its obligations hereunder beyond any applicable cure period at the time
         of scheduled reduction hereunder, after the end of the 2nd Lease Year
         the Security Deposit Amount shall be reduced to the following amounts
         during the following periods:

                                       52

<PAGE>



<TABLE>
<CAPTION>
                               Lease Year                     Security Deposit Amount
                               ----------                     -----------------------
                     <S>                                      <C>
                                   3                               $1,600,000.00

                                   4                               $1,200,000.00

                     5 through 7 and the Extension
                           Term if applicable                       $800,000.00

</TABLE>


         In implementation thereof, after any reduction hereunder, if the amount
         of the Security Deposit held by Landlord exceeds the Security Deposit
         Amount required hereunder, Landlord shall remit such excess to Tenant
         within 5 business days of Tenant's request therefor, however there
         shall be no more than one such remittance per reduction hereunder.

                                   ARTICLE 13

                          TENANT'S EMERGENCY GENERATOR

13.1     TENANT'S EMERGENCY GENERATOR. Tenant shall have the right to install
         (in accordance with the terms and conditions of the Lease), operate and
         maintain an emergency back-up generator (the "Generator") and 1
         accessory fuel tank (the "Tank") each in locations designated by
         Landlord.

13.2     TERMS OF USE. The space utilized by Tenant for the Generator and Tank
         shall not be included in the Rentable Area of the Premises and no Fixed
         Rent or Additional Rent shall be payable therefor but all of the other
         provisions of this Lease shall apply thereto, except that Landlord
         shall not have any obligation to provide any services thereto.
         Notwithstanding anything herein to the contrary, Tenant's right to
         install the Generator and Tank shall be subject to Landlord's
         reasonable approval of the manner in which the Generator and Tank are
         installed, the manner in which any cables and wires are run to and from
         the Generator to the Premises and any fuel lines are run from the Tank
         to the Generator and the measures that will be taken to eliminate any
         vibrations or sound disturbances from the operation of the Generator
         and to minimize the hazards presented by the Tank. Tenant shall be
         solely responsible for obtaining all necessary governmental and
         regulatory approvals and for the cost of installing, operating,
         maintaining and removing of the Generator and Tank. Tenant shall also
         be responsible for the cost of all utilities consumed in the operation
         of the Generator.

13.3     INSTALLATION, OPERATION, MAINTENANCE AND REMOVAL. (a) Tenant shall be
         responsible for assuring that the installation, maintenance, operation
         and removal of the Generator and Tank will in no way damage the
         Building. Tenant agrees to be responsible for any damage caused to the
         Building or Property in connection with the installation,

                                       53

<PAGE>



         maintenance, operation or removal of the Generator and Tank and, in
         accordance with the terms of Section 6.1.5 of this Lease, to indemnify,
         defend and hold Landlord and all Landlord Affiliates harmless from all
         liabilities, obligations, damages, penalties, claims, costs, charges
         and expenses, including, without limitation, reasonable architects' and
         attorneys' fees (if and to the extent permitted by law), which may be
         imposed upon, incurred by, or asserted against Landlord in connection
         with the installation, maintenance, operation or removal of the
         Generator and Tank.

         (b) Tenant shall be responsible for the installation, operation,
         cleanliness, maintenance and removal of the Generator, Tank and
         appurtenances, all of which shall remain the personal property of
         Tenant, and shall be removed by Tenant at its own expense at the
         termination of the Lease. Tenant shall repair any damage caused by such
         removal, including the patching of any holes to match, as closely as
         possible, the color surrounding the area where the Generator, Tank and
         appurtenances were attached. Such maintenance and operation shall be
         performed in a manner to avoid any unreasonable interference with any
         other tenants or Landlord. Tenant agrees to maintain the Generator and
         Tank in good condition and repair. If Tenant fails to perform any of
         its obligations under this Article 13 and such failure continues for 10
         business days after written notice from Landlord, then, in addition to
         and not in lieu of any of Landlord's other remedies on account thereof,
         at Landlord's election, exercisable by and effective upon written
         notice to Tenant, Tenant's rights under this Article 13 shall terminate
         and Tenant shall immediately remove the Generator and Tank from the
         Building and the Property and repair any damage caused by the
         installation and/or removal thereof.

13.4     ACCESS TO GENERATOR AREA. Tenant, upon prior notice to Landlord and
         subject to the reasonable rules and regulations enacted by Landlord,
         shall have access to the Generator and Tank for the purpose of
         installing, repairing, maintaining and removing them. Tenant shall only
         test the Generator and Tank outside Normal Business Hours and upon
         prior notice to Landlord.

                                       54

<PAGE>

         WITNESS the execution hereof under seal on the day and year first above
written:

                                        Landlord:

                                        EAST OFFICE OPERATING
                                        LIMITED PARTNERSHIP


                                        By:  Commonwealth Flats
                                             Development East Corp.,
                                             Its general partner


                                        By: /s/ John Drew
                                           -----------------------------
                                           Name: John Drew
                                           Title:

                                        Tenant:

                                        BREAKAWAY SOLUTIONS, INC.


                                        By: /s/ Gordon Brooks
                                           -----------------------------
                                           Name: Gordon Brooks
                                           Title: President and Chief
                                                  Executive Officer


                                       55
<PAGE>


                                    EXHIBIT A

                                LEGAL DESCRIPTION

         The land, together with all buildings and improvements thereon, shown
as Parcel B-2 on a plan of land entitled "ALTA/ACSM Land Title Survey prepared
for Commonwealth Flats Development L.P. World Trade Center Boston-East Office
Building and Park South Boston, Massachusetts" dated May 27, 1998, prepared by
Cullinane Engineering and recorded with the Suffolk County Registry of Deeds
("Suffolk Deeds") in Book 23335, Page 76 (the "Plan") and more particularly
described in accordance with said Plan as follows:

<TABLE>

<S>           <C>

Beginning     at a point on the southerly side of Northern Avenue at the
              northwesterly corner of Parcel B-2;

Thence        by the southerly side of Northern Avenue, S61(degree) 19' 13"E,
              160.00 feet;

Thence        by the westerly side of Parcel D, S28(degree) 40' 47"W, 389.00
              feet;

Thence        by New Congress Street, N61(degree) 19' 13"W, 160.00 feet;

Thence        by the easterly side of Seaport Lane, N28(degree) 40' 47"E,
              389.00 feet to be point and place of beginning

</TABLE>


Containing, according to said Plan, 62,240 square feet of land, more or less.

                             DESCRIPTION OF PARCEL D

         The land, together with all buildings and improvements thereon, shown
as Parcel D on the Plan and more particularly described in accordance with said
Plan as follows:

<TABLE>
<S>           <C>
Beginning     at a point of the southerly side of Northern Avenue, at the
              northeasterly corner of Parcel B-2;

Thence        by the southerly side of Northern Avenue, S61(degree) 19' 13"E,
              150.01 feet;

Thence        by the westerly side of D Street, S28(degree) 40' 47"W, 389.00
              feet;

Thence        by New Congress Street, N61(degree) 19'13", 150.01 feet;

Thence        by the easterly side of Parcel B-2, N 28(degree) 40' 47"E, 389.00
              feet to the point and place of beginning.
</TABLE>

Containing, according to said Plan, 58,359 square feet of land, more or less.

<PAGE>


                                    EXHIBIT B

                            PLAN SHOWING THE PREMISES



                                   8TH FLOOR

                       INITIAL SPACE AND ADDITIONAL SPACE




<PAGE>


                                    EXHIBIT B

                            PLAN SHOWING THE PREMISES



                                   7TH FLOOR

                       INITIAL SPACE AND ADDITIONAL SPACE




<PAGE>


                                    EXHIBIT B

                            PLAN SHOWING THE PREMISES



                                   6TH FLOOR PLAN

                 WORLD TRADE CENTER -- EAST OFFICE BUILDING BREAKAWAY



<PAGE>

                                    EXHIBIT C

                           COMMENCEMENT DATE AGREEMENT
                                     FOR THE
                       INITIAL SPACE AND ADDITIONAL SPACE



         _________________ ("Landlord") and ________________ ("Tenant") are
parties to a lease ("Lease") dated ____________ of premises in a building
known as World Trade Center East, Two Seaport Lane, Boston, Massachusetts.
Landlord and Tenant hereby acknowledge and agree that the term of the Lease
of the Initial Space and the Additional Space began on the Commencement Date
for the Initial Space and the Additional Space which occurred on
__________________ and will end on ____________________ unless extended or
terminated earlier pursuant to provisions set forth in the Lease.

         Executed under seal this ____ day of __________, 19__.

                                    LANDLORD:


                                    By:
                                       ----------------------------------
                                          Its:


                                    TENANT:


                                    By:
                                       ----------------------------------
                                          Its:


<PAGE>



                                    EXHIBIT C

                           COMMENCEMENT DATE AGREEMENT
                                     FOR THE
                                 EXPANSION SPACE



         _________________ ("Landlord") and ________________ ("Tenant") are
parties to a lease ("Lease") dated ____________ of premises in a building
known as World Trade Center East, Two Seaport Lane, Boston, Massachusetts.
Landlord and Tenant hereby acknowledge and agree that the term of the Lease
for the Expansion Space began on the Commencement Date for the Expansion
Space which occurred on __________________ and will end on
____________________ unless extended or terminated earlier pursuant to
provisions set forth in the Lease.

         Executed under seal this ____ day of __________, 19__.

                                    LANDLORD:


                                    By:
                                       ----------------------------------
                                          Its:


                                    TENANT:


                                    By:
                                       ----------------------------------
                                          Its:



<PAGE>


                                    EXHIBIT D

                              BUILDING DESCRIPTION


                             WORLD TRADE CENTER EAST
                               PROJECT DESCRIPTION


<PAGE>

                          WORLD TRADE CENTER -- BOSTON
                             EAST OFFICE BUILDING
                              SITE LOCATION PLAN



<PAGE>
                           WORLD TRADE CENTER BOSTON
                             EAST OFFICE BUILDING


<PAGE>
                           WORLD TRADE CENTER BOSTON
                             EAST OFFICE BUILDING

<PAGE>
                           WORLD TRADE CENTER BOSTON
                             EAST OFFICE BUILDING

<PAGE>
EXHIBIT E
WTC EAST OFFICE BUILDING
BASE BUILDING WORK SPECIFICATIONS

         The following systems shall be part of the base building:

A.  HEATING VENTILATION AND AIR CONDITIONING

     1.  The HVAC system consists of floor mounted, water-cooled, self-contained
         air handling units which are served by a multi-celled cooling tower
         system with a capacity of 2,250 tons. Outdoor air for ventilation will
         be provided at the rate of 20/CFM per person based on one person per
         150 usable feet, as per the BOCA National Mechanical Code.

     2.  Each office floor will be served by a water-cooled package air
         conditioning unit, each with its own set of compressors and a waterside
         economizer. Landlord provided medium pressure ring ductwork shall be
         joined and supported per SMACNA standards. Landlord to provide all
         thermal (external wrap) insulation, fire dampers (as required by code)
         for base building medium pressure ductwork installed in Tenant's
         Premises. All low pressure ductwork insulation will be part of TIW. No
         ducts will be interior lined. Sound attenuators will be used to control
         sound.

     3.  Air distribution will be provided by Variable air volume (VAV) boxes.
         Fourteen perimeter fan powered VAV boxes, including electric heating
         coils with built-in transformer controls, will be provided and
         installed by the Landlord. These boxes are set up to handle
         approximately 550 square feet each. Landlord will provide a material
         allowance for one interior non-fan powered, VAV box (i.e. with controls
         and thermostat, and without electric heat) for every 1500 usable square
         feet, less the area covered by the 14 perimeter boxes. Installation of
         these interior VAV boxes will be part of Tenant Improvement Work (TIW).
         If any additional perimeter or interior VAV Boxes are required, they
         will be part of TIW. The medium pressure duct will be connected to the
         floor air handling units and the perimeter fan powered VAV units by the
         landlord. All low pressure distribution from the perimeter VAV and
         interior VAV boxes, as well as medium pressure connections to the
         interior VAV boxes will be part of TIW.

     4.  The HVAC system will be capable of providing a cooling capacity of 5
         watts per RSF for tenant light and power. Additional cooling capacity
         of 25 tons per floor will be available in each floor mechanical room at
         valved and capped condenser water outlets for loads greater than 5
         watts square feet, and or after hour loads. It is estimated the
         condenser water from this supplemental cooling will cost $500/ton/year.

                                       1

<PAGE>



     5.  Smoke evacuation, Stair pressurization and garage exhaust systems will
         be provided and served from a standby emergency generator in accordance
         with the current high-rise code.

     6.  The building will be controlled through a "Building Energy Management
         System", which will monitor and control building systems. Such system
         is described in more detail in paragraph E.3 below.

     7.  Thermostats for the perimeter VAV boxes will be provided and installed
         on top of the VAV box with 30 feet of wire. Final installation of
         thermostat will be part of TIW.

B.  ELECTRICAL

     1.  Building electric service is designed to provide 6 watts per RSF, 4
         watts for general power, and two watts for lighting, with an additional
         3 watts/RSF available at the floor electrical room for other tenant
         needs on the floor. The distribution panel shall be part of TIW for
         full floor tenants. On multi tenant floors, Landlord will provide
         multiple distribution taps.

     2.  Central mechanical equipment loads, elevators, lights and power for
         public spaces will be provided with additional electrical capacity
         beyond the above stated tenant lighting and power allocation.

     3.  Electrical power will be provided by Boston Edison via redundant
         primary (i.e. 13,800 volts) service to the building. Two primary
         feeders and redundant transformers are provided. On single tenant
         floors electrical consumption will be individually check metered for
         each floor for tenant light and power as well as for HVAC requirements.
         On multi tenant floors each tenant will be individually check metered
         for tenant light and power. HVAC electrical will be billed on a square
         foot pro rata basis during normal operating hours. After normal
         operating hours electrical HVAC cost will be billed at an hourly rate
         determined by Landlord on the basis of reasonable engineering
         calculations.

     4.  Electrical energy provided by the landlord will be charged to the
         tenant as indicated in the lease.

     5.  Emergency power will be provided by a diesel powered emergency
         generator for life safety loads required by code.

     6.  Dual-feed telephone service is available from local exchange carriers
         in the building. This redundancy will be extended throughout the
         building. Fiber optic bandwidth and digital services will be available
         to the building. Landlord will provide empty 4-inch sleeves located in
         the building core telecom closets for installation of Tenant's
         telephone wiring by Tenant's phone service provider(s).

                                       2

<PAGE>



C.  PLUMBING

     1.  Toilet rooms will be provided on all tenant floors and will meet or
         exceed code requirements for quality and type of fixtures as well as
         handicapped accessibility. Core toilet rooms will be served by a
         dedicated exhaust duct and fan system to meet all applicable codes.

     2.  Four (4) each waste, vent, and cold water stacks will be available on
         each floor to provide for tenant requirements.

D.  FIRE PROTECTION/LIFE SAFETY SYSTEMS

     1.  The building will provide an automatic sprinkler system covering the
         complete base building to meet existing codes. Modification of this
         system to meet tenant design requirements will be part of Tenant
         Improvement Work. System design must meet Factory Mutual Standards.

     2.  A state-of-the-art high rise fire alarm system providing automatic
         activation of the smoke control systems will be provided at Landlord's
         expense. Provision and distribution of fire alarm system that is
         specific to Tenant space design will be part of Tenant Improvement
         Work.

 E.  ENERGY CONSERVATION FEATURES

     1.  Insulation, air barrier and vapor barrier at exterior walls is provided
         as per code.

     2.  Insulated glass with a low E reflective coating and a thermal efficient
         window system. Base Building exterior insulated glass will have a
         minimum air space of 1/2" as required to meet or exceed STC 35
         criteria. High performance elastometric non hardening sealants that do
         not diminish the STC 35 rating will be used for exterior joints,
         including the window and curtain wall perimeters.

     3.  Landlord will furnish and install an Energy Management System ("EMS")
         which will control cost and comfort by monitoring HVAC functions. The
         EMS will allow Landlord to enter and change setpoints, override
         schedules, diagnose equipment problems, track energy use and
         acknowledge alarms from a central location. The EMS will have the
         capability of remote control through modem access. The brand and model
         EMS will be comparable to those installed in typical Class A high rise
         building.

F.  ACCESS CONTROL

     1.  A card access control system will be provided for after hours building
         and elevator access. This will also secure access to floors.

                                       3

<PAGE>

     2.  A lobby attendant will be stationed in the main lobby during normal
         working hours. A security guard will be stationed in the main lobby
         after normal working hours - (i.e. 24-hour coverage). Both the
         attendant and the security guard will monitor building security
         cameras.

G.  FINISHES

TENANT'S PREMISES

     1.  Floor shall be delivered ready for carpet.

     2.  Perimeter wall and columns shall be drywalled and taped to a level 1
         finish.

     3.  Interior core walls shall be drywalled and taped to a level 1 finish.
         Core doors shall be primed and ready to accept finish.

     4.  Standard finished ceiling height shall be 9', assuming Tenant specifies
         conventional lay-in ceiling construction and normal care is taken in
         designing and coordinating tenants electrical and mechanical work.

     5.  Landlord shall furnish and install building standard window blinds for
         all exterior windows. A standard window soffit detail will be furnished
         by the Landlord, and constructed by the tenant as part of TIW.

     6.  A common shaft for Tenant's installed kitchen exhaust ducts shall be
         provided by Landlord at Landlord's expense. The shaft will meet all
         fire ratings required by applicable codes, including rated clean-out
         access doors. Tenants will be required to fire-rate their own duct
         riser within the common shaft.

     MULTI-TENANT FLOOR ELEVATOR LOBBIES

     1.  Lobby ceiling will be 2'x 2' acoustical tile laid in a narrow profile
         recessed grid system.

     2.  Lobby floorings will be combination loop/cut pile carpeting with wood
         base.

     3.  Walls will receive a fabric wall covering. Elevator doors and frames
         will be painted.

     4.  Lobby lighting shall be provided to level of approximately 25-foot
         candles.

     5.  Core doors shall have a final finish.

                                       4

<PAGE>



     CORRIDORS FROM ELEVATOR LOBBIES
     (MULTI-TENANT FLOORS ONLY.)
     [CORRIDORS ON MULTI-TENANT FLOORS SHALL BE PROVIDED BY LANDLORD AT
     LANDLORD'S COST.]

     1.  Corridor partitions shall be constructed of metal studs with gypsum
         wallboard on the corridor side extending above ceiling to the underside
         of structure.

     2.  Corridor ceilings will be 2' x 2' acoustical tile laid in a narrow
         profile recessed grid system.

     3.  Corridor flooring will be a combination loop/cut pile carpeting with
         vinyl base.

     4.  Corridor walls will receive a polymix finish. Doors and frames will be
         painted with an enamel paint.

     5.  Lighting will consist of recessed 2' x 2' fluorescent parabolic lens
         fixtures.

     Core Toilet Rooms

     1.  All walls will have ceramic tile to a height of approximately 5' with
         painted gypsum wallboard above.

     2.  Floor finish will be ceramic tile.

     3.  Ceilings will be gypsum wallboard.

     4.  Lavatory counter tops will be granite with under-mounted sinks.

     5.  Toilet rooms will comply with handicapped access requirements of the
         Massachusetts Architectural Access Board and the Americans with
         Disabilities Act.

     6.  Toilet partitions will be painted metal or plastic laminate and ceiling
         hung.

     7.  Lighting will be indirect cove lights.

H.       STRUCTURAL

     1.  Office floor loading is designed for:

         60 psf live load
         20 psf partition load
         ------
         TOTAL: 80 psf

     2.  Floor slabs shall be constructed to a minimum Ff. 20 floor flatness.

                                       5

<PAGE>



     3.  Floor slabs shall be suitable for installation of carpet and will be
         constructed such that 10' freestanding (unleveled) straight edge
         placed anywhere on the slab and allowed to rest upon two high spots
         has a gap between the straight edge and the floor not exceeding 1/4".

I.  VERTICAL TRANSPORTATION

     1.  A group of 8 first class passenger elevators will be provided to
         service the Building. Each cab is rated at 3500 pound capacity with a
         speed of 500 FPM, having a total travel of 204'-0". Under one way peak
         traffic conditions, the elevator system's five-minute calculated
         handling capacity is 12.5% of the estimated building population. Under
         heavy two traffic conditions, the calculated handling capacity is 12%
         of the estimated building population.

         Under peak one way traffic conditions, the calculated average interval
         is just over 20 seconds; the calculated average waiting time is 17
         seconds; and the calculated average destination time is less than one
         minute.

         Under heavy two-way traffic conditions, the calculated average waiting
         time is 18 seconds, and the calculated average destination time is also
         less than one minute.

     2.  One service elevator serving P-1, 1-16, and Penthouse floors.

     3.  Two garage passenger elevators.

     4.  During the performance of Tenant Improvement Work, Landlord will
         provide at its expense elevator access and elevator operator(s) as well
         as normal building security. During after hours use of elevators
         (during the performance of Tenant Improvement Work), Tenant shall bear
         the cost for overtime elevator operator (s), and Tenant specific
         security as a part of Tenant Improvement Work. Tenant shall not be
         responsible for elevator charges or laborer charges during move-in.
         Tenant will be responsible for removal of all cardboard and trash
         associated with move-in.

                                       6

<PAGE>



EXHIBIT F
WORLD TRADE CENTER EAST
OFFICE SPACE CLEANING SPECIFICATIONS


I.       INTERIOR TENANT AREAS

NIGHTLY MONDAY THROUGH FRIDAY, EXCLUDING HOLIDAYS

1.       Dust mop all stone, ceramic tile, terrazzo and other type of un-waxed
         flooring.

2.       Dust mop all vinyl, asphalt, rubber and similar types of flooring.
         Remove gum and other substances, spot mop if necessary.

3.       Vacuum all carpeted areas.

4.       Dust mop all private and public stairways and vacuum if carpeted.

5.       Hand dust and wipe clean all horizontal surfaces including furniture,
         file cabinets, fixtures, and windowsills, using chemically treated dust
         cloth. PAPERS ON DESKS SHALL REMAIN UNDISTURBED.

6.       Dust and sanitize all telephones using disinfectant solution. Care is
         to be taken NOT to depress buttons thus altering phone programs, i.e.,
         call forwarding.

7.       Remove fingerprints from all painted surfaces near light switches,
         entrance doors, drinking fountains, etc.

8.       Remove all gum and foreign matter on sight.

9.       Empty and clean all waste receptacles and remove waste materials to
         compactors. Replace liners as necessary.

10.      Damp wash interiors of all waste disposal receptacles and wash as
         necessary.

11.      Clean and sanitize all water fountains, and water coolers with a
         disinfectant solution. Wash all sinks and the floors adjacent to them
         on a nightly basis.

12.      Spot mop floors for spills, etc.

13.      Empty and damp clean all ashtrays.

                                       1

<PAGE>



14.      Clean all low ledges, shelves, bookcases, chair rails, trim, pictures,
         charts etc. within reach.

15.      Clean mirrors, metal work, glass tabletops.

16.      Upon completion of work, all slop sinks are to be thoroughly cleaned
         and all cleaning equipment and supplies stored neatly in locations
         designated by the Management of the building.

17.      All cleaning operations shall be scheduled so that a minimum of lights
         are to be left on at any time. Upon completion of cleaning all lights
         are to be turned off. All entrance doors are to be kept locked during
         the cleaning operation.

18.      Spot clean both sides of tenant entry glass doors.

19.      Spot clean desk tops and counter tops.

20.      Pick up all recyclable material and take to appropriate place.

WEEKLY

1.       Hand dust all door louvers and other ventilating louvers within reach.

2.       Dust all baseboards.

3.       In high traffic areas, damp mop if necessary and apply spray-buffing
         solution in a fine mist and buff with a synthetic pad.

4.       Damp mop all non-carpeted and public stairways.

5.       Wipe clean all bright work.

6.       Completely clean interior glass partitions and doors.

7.       Dust all chair rails.

8.       Dust walls up to normal reach.

MONTHLY

1.       Hose vacuum underneath all furniture.

2.       Dust all vertical surfaces such as walls, furniture, partitions and
         surfaces not reached in nightly cleaning.

                                       2

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3.       Dust exterior of lighting fixtures.

QUARTERLY

1.       Wash all baseboards.

2.       Dust all exterior window blinds

3.       Dust and/or clean all diffusers

OTHER

1.       Cleaning of computer rooms will be responsibility of individual
         tenants.

2.       Coffee stations and dishware are responsibility of the tenant.


II.      PUBLIC CORRIDORS, STAIRWELLS (EMERGENCY EGRESS), SERVICE AREAS

NIGHTLY

1.       Vacuum and spot clean carpeting.

2.       Sweep and mop public concrete floors.

3.       Sweep and mop public stairwells and landings.

4.       Clean baseboards of scuffs and marks.

5.       Empty and clean ashtrays and sand urns.

6.       Clean all directories, signage kiosks, wall signage and electric
         kiosks.

7.       Clean corridor glass and metal work.

8.       Spot clean walls, ceilings, lights, etc.

9.       Clean telephones and telephone booth areas.

10.      Clean and sanitize all public water fountains.

11.      Dust all handrails.

12.      Dust to hand height all horizontal surfaces of equipment ledge, sill,
         shelves, radiators, frames, partitions, handrails, etc.

                                       3

<PAGE>

13.      Damp wipe all public granite seating areas and surrounding granite
         treatments.

14.      Clean exterior surfaces of all trash containers and planters.

15.      Keep slop sinks, closets, supply rooms and other janitorial areas in a
         clean orderly condition.

16.      Keep electrical and telephone closets clean and free of storage.

17.      Replace burned out light bulbs.

WEEKLY

1.       Clean all door vents.

2.       Dust all vertical surfaces within reach.

3.       Sweep emergency egress stairs and landings.

MONTHLY

1.       Wash all corridor glass and metal completely including atriums.

2 .      Dry shampoo heavily traveled carpeted areas.

QUARTERLY

1.       Clean handrails, wall mounted equipment casings, landings, walls, kick
         plates in emergency egresses.

2.       Shampoo and extract all carpeting.

3.       Damp clean inside reflectors of high hat lighting fixtures.

SEMI-ANNUALLY

1.       Vacuum soffits containing fluorescent fixtures in atrium areas.

2.       Wash windows, ledges, plants and light bulbs on inside of both atriums.

                                       4

<PAGE>



III.     RESTROOMS

BUILDING OPERATING HOURS

Day porters and matrons will be assigned to perform the following:

1.       Empty trash containers and insert new liners.

2.       Sweep and spot wash floors as necessary.

3.       Spot clean sinks and mirrors. Clean and spot polish shelves and metal
         dispensers. Check for Graffiti and spot clean if necessary.

4.       Ensure cleanliness of urinals and toilets.

5.       Refill all dispenser units as needed.

NON-OPERATING HOURS

1.       Damp wash, sanitize (using disinfectant solution) and polish all
         fixtures including toilet bowls, urinals and wash basins.

2.       Sweep and wash floors with approved germicidal solution.

3.       Wash and polish mirrors, powder shelves, dispensers, hand dryers,
         bright work including flushometers, piping and toilet seat hinges.

4.       Clean and sanitize BOTH sides of toilet seats.

5.       Empty all containers and disposal units and insert new liners.

6.       Wash and sanitize interiors and exteriors of all containers prior to
         inserting new liners.

7.       Empty, clean and sanitize all sanitary napkin disposal units.

8.       Dust and spot wash where necessary partitions, tile walls, dispensers,
         ceiling lights, switches and receptacles.

9.       Refill all dispensers to normal limits including sanitary supplies,
         soap, tissue, towels, etc.

10.      Remove all rubbish and transport to compactor.

11.      Dust ceiling door vents and doorframes.

                                       5

<PAGE>

PERIODIC

MONTHLY

1.       Machine scrub all tile floors, hand brush corners and hand brush toilet
         edges with approved germicidal detergent solution.

2.       Wash completely all partitions, tile walls and enamel surfaces.

IV.      WINDOW CLEANING

PERIODIC

1.       External windows will be washed and cleaned a minimum of three times
         per year. Internal windows will be washed and cleaned a minimum of two
         times per year.

                                       6

<PAGE>



                                    EXHIBIT G

                              RULES AND REGULATIONS


1.       The sidewalks, entrances, passages, corridors, vestibules, halls,
         elevators, or stairways in or about the Building shall not be
         obstructed by Tenant.

2.       Tenant shall not place objects against glass partitions, doors or
         windows which would be unsightly from the Building corridor or from the
         exterior of the Building.

3.       Tenant shall not waste electricity or water in the Building premises
         and shall cooperate fully with Landlord to assure the most effective
         operation of the Building heating and air conditioning systems. All
         regulating and adjusting of heating and air-conditioning apparatus
         shall be done by the Landlord's agents or employees.

4.       Tenant shall not use the Premises so as to cause any increase above
         normal insurance premiums on the Building.

5.       No bicycles, vehicles, or animals (except guide dogs for the disabled)
         of any kind shall be brought into or kept in or about the Premises. No
         space in the Building shall be used for manufacturing or for the sale
         of merchandise of any kind at auction or for storage thereof
         preliminary to such sale.

6.       Tenant shall cooperate with Landlord in minimizing loss and risk
         thereof from fire and associated perils.

7.       The water and wash closets and other plumbing fixtures shall not be
         used for any purposes other than those for which they were designed and
         constructed and no sweepings, rubbish, rags, acid or like substance
         shall be deposited therein. All damages resulting from any misuse of
         the fixtures shall be borne by the Tenant.

8.       Landlord may from time to time adopt appropriate systems and procedures
         for the security or safety of the Building, any persons occupying,
         using, or entering the Building, or any equipment, finishings, or
         contents of the Building, and Tenant will comply with Landlord's
         reasonable requirements relative to such systems and procedures.

9.       No cooking will be done or permitted by Tenant within the Premises,
         except in areas of the Premises which are specifically constructed for
         cooking and except that use by the tenant of microwave ovens and
         Underwriters' Laboratory approved equipment for brewing coffee, tea,
         hot chocolate, and similar beverages will be permitted, provided that
         such use is in accordance with all applicable federal, state, and city
         laws, codes, ordinances, rules, and regulations.

                                       1

<PAGE>

10.      The elevator designated for freight by Landlord will be available for
         use by all tenants in the Building during Normal Business Hours and
         pursuant to such procedures as Landlord may determine from time to
         time. The persons employed to move Tenant's equipment, material,
         furniture, or other property in or out of the Building must be
         acceptable to Landlord. All moving operations will be conducted at such
         times and in such a manner as Landlord will direct, and all moving will
         take place during non-Business Hours unless Landlord agrees in writing
         otherwise.

11.      Tenant acknowledges that the Building has been designated a non-smoking
         building. At no time shall Tenant permit its agents, employees,
         contractors, guests or invitees to smoke in the Building or, except in
         specified locations, directly outside the Building.

12.      Landlord reserves the right at any time to rescind, alter or waive any
         rule or regulation at any time prescribed for the Building and to
         impose additional reasonable rules and regulations when in its judgment
         deems it necessary, desirable or proper for its best interest and for
         the best interest of the tenants and no alteration or waiver of any
         rule or regulation in favor of one tenant shall operate as an
         alteration or waiver in favor of any other tenant, provided such rules
         and regulations do not diminish Tenant's rights under the Lease.
         Landlord shall not be responsible to any tenant for the nonobservance
         or violation by any other tenant however resulting of any rules or
         regulations at any time prescribed for the Building

                                       2

<PAGE>



                                    EXHIBIT H

                           TENANT ESTOPPEL CERTIFICATE


TO:                          ("Mortgagee" or "Purchaser")
   --------------------------

THIS IS TO CERTIFY THAT:

         1. The undersigned is the tenant (the "Tenant") under that certain
lease (the "Lease") dated __________, 199_, by and between ____________ as
landlord (the "Landlord"), and the undersigned, as Tenant, covering those
certain premises commonly known and designated as _______________ (the
"Premises") in the building located at ______________, ________________,
Massachusetts.

         2. The Lease (i) constitutes the entire agreement between the
undersigned and the Landlord with respect to the Premises, (ii) is the only
Lease between the undersigned and the Landlord affecting the Premises and (iii)
has not been modified, changed, altered or amended in any respect, except (if
none, so state):

           ---------------------------------------

           ---------------------------------------

           ---------------------------------------

         3. The undersigned has accepted and now occupies the Premises as of the
date hereof, and all improvements, if any, required by the terms of the Lease to
be made by the Landlord have been completed and all construction allowances to
be paid by Landlord have been paid. In addition, the undersigned has made no
agreement with Landlord or any agent, representative or employee of Landlord
concerning free rent, partial rent, rebate of rental payments or any other type
of rental or other economic inducement or concession except (if none, so state):

           ---------------------------------------

           ---------------------------------------

           ---------------------------------------

         4.       1.     The term of the Lease began (or is scheduled to begin)
                         on _________ , 19___ and will expire on _________,
                         19__;

                  2.     The fixed rent for the Premises has been paid to and
                         including _______________, 19__;

                  3.     The fixed rent being paid pursuant to the Lease is at
                         the annual rate of $____________; and

                                       1

<PAGE>



                  4.     The escalations payable by Tenant under the Lease are
                         currently $______, based on a pro rata share of
                         ______%, and have been reconciled through _______,
                         19__.


         5. (i)  To the best of Tenant's knowledge, no party to the Lease is in
default, (ii) the Lease is in full force and effect, (iii) the rental payable
under the Lease is accruing to the extent therein provided thereunder, (iv) to
the best of Tenant's knowledge, as of the date hereof the undersigned has no
charge, lien or claim of off-set (and no claim for any credit or deduction)
under the Lease or otherwise, against rents or other charges due or to become
due thereunder or on account of any prepayment of rent more than one (1) month
in advance of its due date, and (v) Tenant has no claim against Landlord for any
security, rental, cleaning or other deposits, except (if none, so state):

           ---------------------------------------

           ---------------------------------------

         6. Since the date of the Lease there are no actions, whether voluntary
or otherwise, pending against the undersigned under the bankruptcy,
reorganization, arrangement, moratorium or similar laws of the United States,
any state thereof of any other jurisdiction.

         7. Tenant has not sublet, assigned or hypothecated or otherwise
transferred all or any portion of Tenant's leasehold interest, except (if none,
so state):

           ---------------------------------------

           ---------------------------------------

         8. Neither Tenant nor Landlord has commenced any action or given or
received any notice for the purpose of terminating the Lease, nor does Tenant
have any right to terminate the Lease, except (if none, so state):

           ---------------------------------------

           ---------------------------------------

           ---------------------------------------

         9. Tenant has no option or preferential right to purchase all or any
part of the Premises (or the real property of which the Premises are a part) nor
any right or interest with respect to the Premises or the real property of which
the Premises are a part. Tenant has no right to renew or extend the term of the
Lease or expand the Premises except (if none, so state):

           ---------------------------------------

           ---------------------------------------

           ---------------------------------------

         10. The undersigned acknowledges that the parties named herein are
relying upon this estoppel certificate and the accuracy of the information
contained herein in making a loan

                                       2

<PAGE>

secured by the Landlord's interest in the Premises, or in connection with the
acquisition of the Property of which the Premises is a part.

                                       3

<PAGE>



         EXECUTED UNDER SEAL AS OF _____________, 19__.

                                   TENANT:

                                   -------------------------

                                   By:
                                      ----------------------
                                      Name:
                                      Title:
                                      Duly Authorized


                                       4

<PAGE>



                                    EXHIBIT I

               NONDISCRIMINATION AND AFFIRMATIVE ACTION COVENANTS

         With respect to the exercise of all rights and privileges granted under
this Lease, Tenant agrees that Tenant, its successors in interest, subtenants,
and assigns shall:

         (a)      not discriminate against any person, employee, or applicant
                  for employment because of race, color or religion, national
                  origin, age, sex, sexual orientation, disability, or Vietnam
                  era veteran status in the use of the Premises, including the
                  hiring and discharging of employees, the provision or use of
                  services, and the selection of suppliers and contractors;

         (b)      conspicuously post notices to employees and prospective
                  employees setting forth the Fair Employee Practices Law of the
                  Commonwealth of Massachusetts; and

         (c)      comply with all applicable federal and state laws, rules and
                  regulations and orders and Massport rules and orders (provided
                  copies of such Massport rules and orders have been provided to
                  Tenant) pertaining to Civil Rights and Equal Opportunity.

Non-compliance by Tenant, its successors in interest, subtenants, or assigns
with the foregoing (beyond any cure period set forth in the Lease) shall
constitute a material breach of this Lease. Tenant shall indemnify and hold
harmless Landlord and Massport from any claims and demands of third persons
resulting from non-compliance therewith. The provisions of this Exhibit I shall
survive the expiration or any early termination or cancellation of this Lease
with respect to the period ending on such expiration or earlier termination .



<PAGE>



                                    EXHIBIT J

                          RENTABLE AREA DEFINITION AND
                               MEASUREMENT METHOD



RENTABLE AREA

MEASUREMENT STANDARDS - SINGLE TENANCY FLOORS

Three steps, in sequence, are to be followed to determine the total Rentable
Area: (i) compute gross area, (ii) deduct certain areas, (iii) add applicable
share of attributable area (see paragraph c below). Gross area minus such
deductions is referred to in this Lease as "usable area."

(a) GROSS AREA: The gross area of a floor shall be the entire area within the
exterior walls. The measurement along the entire exterior wall shall be taken to
a line established by the horizontal plane of the inside of the glass or other
transparent material.

(b) DEDUCTIONS FROM THE GROSS AREA: The following non-rentable building areas
and their enclosing walls are to be deducted:

1.  Elevator shafts and mechanical shafts.
2.  Egress stairways.
3.  Attributable areas, if any, within the gross area.

(c) ATTRIBUTABLE AREA: The attributable areas shall include, without limitation,
the following: common facilities, including, mechanical and electrical equipment
in the penthouse, mail room, security desk and service area, public lobbies and
circulation areas, fire control room, internal loading docks, and switchgear and
telephone data rooms. The parties acknowledge and agree that the applicable
share of attributable area for floors 6, 7 and 8 is 3,388 per floor.

                                       1

<PAGE>



MEASUREMENT STANDARDS - MULTIPLE TENANCY FLOORS


The sum of the Total Rentable Area for two or more tenants on a floor shall be
Total Rentable Area for that floor as computed in the manner for single tenancy
floors.

Three steps are to be followed to determine the Total Rentable Area for each
tenant on a multiple occupancy floor: (i) compute the Net Rentable Area for such
floor pursuant to (a) below, (ii) compute the Net Rentable Area for each tenant
pursuant to (b) below; (iii) multiply the Total Rentable Area of such floor (as
defined for single tenancy floors) by a fraction whose numerator is the Net
Rentable Area for such tenant and whose denominator is the Net Rentable Area for
such floor.

(a)      NET RENTABLE AREA FOR ANY FLOOR: The Net Rentable Area shall be the
         gross area as described for single tenancy less the entire core area
         (measured to the finished enclosing walls thereof, but excluding any
         part of the core rented to a tenant) and corridors (measured to the
         finished surface of the office side of the enclosing walls of the
         corridor).

(b)      NET RENTABLE AREA FOR EACH TENANT: Exterior walls are to be measured as
         described in the procedure for gross area. Demising walls between
         tenants are to be equally divided. Corridor walls to the finished
         surface of the office side of the corridor are not to be included in
         the Net Rentable Area of each tenant.

                                       2

<PAGE>


                                    EXHIBIT K

                         LANDLORD'S WIRING INSTRUCTIONS





                  First National Bank of Chicago
                  ABA#: 071000013
                  Account Name:  FMR Corp.
                  Account #:  5938791