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                                                                    Exhibit 10.7

                               RESERVOIR PLACE II
                             WALTHAM, MASSACHUSETTS

                                      LEASE

      THIS INSTRUMENT IS AN INDENTURE OF LEASE in which the Landlord and the
Tenant are the parties hereinafter named, and which relates to space in a
certain building (the "Building") known as Reservoir Place II and with an
address at 1601 Trapelo Road, Waltham, Massachusetts.

      The parties to this Indenture of Lease hereby agree with each other as
follows:

                                    ARTICLE I

                                 REFERENCE DATA

1.1   Subjects 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 Article:

DATE OF LEASE:              January 18, 2000

LANDLORD:                   Boston Properties Limited Partnership, a Delaware
                            limited partnership, the general partner of which is
                            Boston Properties, Inc., a Delaware corporation

LANDLORD'S ORIGINAL         c/o Boston Properties, Inc.
ADDRESS:                    800 Boylston Street, Suite 400
                            Boston, Massachusetts 02199-8001

TENANT:                     Advanced Lumitech, Inc.

TENANT'S ORIGINAL           92 High Rock Street
ADDRESS:                    Needham, MA 02492

TENANT'S CONSTRUCTION
REPRESENTATIVE:             _________________

COMMENCEMENT DATE:          See Section 2.4

RENT COMMENCEMENT


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DATE:                       The earlier of (x) February 1, 2000 or (y) the date
                            upon which Tenant commences to use the Premises for
                            the Permitted Use

TERM OR LEASE TERM
(SOMETIMES CALLED
THE ORIGINAL TERM):         Twenty-Four (24) calendar months (plus the partial
                            month, if any, immediately following the
                            Commencement Date), unless extended or sooner
                            terminated as provided in this Lease.

EXTENSION OPTION:           Not applicable

THE SITE:                   That certain parcel of land located on Trapelo Road,
                            Waltham, Middlesex County, Massachusetts, being more
                            particularly described in Exhibit A attached hereto.

THE BUILDING:               The Building known as Reservoir Place II, and
                            numbered 1601 Trapelo Road, Waltham, Massachusetts,
                            located on the site and containing the Total
                            Rentable Floor Area set forth below.

THE ADDITIONAL BUILDING:    The other Building known as Reservoir Place I
                            located on the Site and containing the Total
                            Rentable Floor Area set forth below.

THE BUILDINGS:              The Building and the Additional Building.

THE COMPLEX:                The Building and the Additional Building together
                            with all parking areas, garage, and structures and
                            the Site.

TENANT'S SPACE:             A portion of the second (2nd) floor of the Building
                            in accordance with the floor plan annexed hereto as
                            Exhibit D and incorporated herein by reference.

NUMBER OF                   Privileges for parking ten (10) automobiles, four
PARKING PRIVILEGES:         (4) of which are located in the garage below the
                            Building, and six (6) of which will be located on
                            the outdoor surface lot.

ANNUAL FIXED RENT:          During the Original Term of this Lease at the annual
                            rate of Eighty-Three Thousand Sixty-One and


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                            00/100 Dollars ($83,061.00) (being the product of
                            (i) 33.00 and (ii) the "Rentable Floor Area of
                            Tenant's Space" (hereinafter defined in this Section
                            1.1). The monthly installment of annual fixed rent
                            during the Original Term is $6,921.75.

BASE OPERATING
EXPENSES:                   Landlord's Operating Expenses (as hereinafter
                            defined in Section 2.6) for calendar year 2000,
                            being January 1, 2000 through December 31, 2000.

BASE TAXES:                 Landlord's Tax Expenses (as hereinafter defined in
                            Section 2.7) for fiscal tax year 2000, being July 1,
                            1999 through June 30, 2000.

TENANT ELECTRICITY:         Initially as provided in Section 2.8 subject to
                            adjustment as provided in Section 2.8.

RENTABLE FLOOR AREA         2,517 square feet.
OF TENANT'S SPACE
(SOMETIMES ALSO
CALLED RENTABLE FLOOR
AREA OF THE PREMISES):

TOTAL RENTABLE FLOOR        368,257 square feet.
AREA OF THE BUILDING:

TOTAL RENTABLE FLOOR        161,734 square feet.
AREA OF THE ADDITIONAL
BUILDING:

TOTAL RENTABLE FLOOR        529,991 square feet.
AREA OF THE BUILDINGS:

PERMITTED USE:              General office purposes.

INITIAL MINIMUM
LIMITS OF TENANT'S
COMMERCIAL GENERAL
LIABILITY INSURANCE:        $2,000,000.00 combined single limit per occurrence
                            on a per location basis

CO-BROKERS:                 Grubb & Ellis, Inc. and Spaulding & Slye Colliers
                            International


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SECURITY DEPOSIT:  $13,843.50

1.2   Exhibits. There are incorporated as part of this Lease:

      EXHIBIT A Description of Site

      EXHIBIT B Tenant Plan and Working Drawing Requirements

      EXHIBIT C Landlord's Services

      EXHIBIT D Floor Plan

      EXHIBIT E Commencement Date Agreement

      EXHIBIT F Intentionally Omitted

      EXHIBIT G List of Mortgages

1.3   Table of Articles and Sections

                            ARTICLE I-REFERENCE DATA

1.1   Subjects Referred to

      1.2   Exhibits

      1.3   Table of Articles and Sections

                ARTICLE II-THE BUILDINGS, PREMISES, TERM AND RENT

2.1   The Premises

      2.1.1 Relocation of Tenant's Space

2.2   Rights To Use Common Facilities

      2.2.1 Tenant's Parking

2.3   Landlord's Reservations

2.4   Habendum

2.5   Monthly Fixed Rent Payments


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2.6   Adjustment for Operating Expenses

2.7   Adjustment for Real Estate Taxes

2.8   Tenant Electricity

              ARTICLE III-CONDITION OF PREMISES; TENANT ALTERATIONS

3.1   Condition of Premises

3.2   Intentionally Omitted

3.3   Tenant Alterations and Additions

3.4   General Provisions Applicable to Construction

3.5.  Special Allowance

            ARTICLE IV-LANDLORD'S COVENANTS; INTERRUPTIONS AND DELAYS

4.1   Landlord's Covenants

      4.1.1 Services Furnished by Landlord

      4.1.2 Additional Services Available to Tenant

      4.1.3 Roof, Exterior Wall, Floor Slab and Common Facility Repairs

      4.1.4 Door Signs

4.2   Interruptions and Delays in Services and Repairs, etc.

                          ARTICLE V-TENANT'S COVENANTS

5.1   Payments

5.2   Repair and Yield Up

5.3   Use

5.4   Obstructions; Items Visible From Exterior; Rules and Regulations

5.5   Safety Appliances; Licenses


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5.6   Assignment; Sublease

5.7   Indemnity; Insurance

5.8   Personal Property at Tenant's Risk

5.9   Right of Entry

5.10  Floor Load; Prevention of Vibration and Noise

5.11  Personal Property Taxes

5.12  Compliance with Laws

5.13  Payment of Litigation Expenses

                         ARTICLE VI-CASUALTY AND TAKING

6.1   Fire and Casualty-Termination or Restoration; Rent Adjustment

6.2   Uninsured Casualty

6.3   Eminent Domain-Termination or Restoration

6.4   Eminent Domain Damages Reserved

                              ARTICLE VII-DEFAULT

7.1   Tenant's Default

7.2   Landlord's Default

                      ARTICLE VIII-MISCELLANEOUS PROVISIONS

8.1   Extra Hazardous Use

8.2   Waiver

8.3   Cumulative Remedies

8.4   Quiet Enjoyment

8.5   Notice To Mortgagee and Ground Lessor


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8.6   Assignment of Rents

8.7   Surrender

8.8   Brokerage

8.9   Invalidity of Particular Provisions

8.10  Provisions Binding, Etc.

8.11  Recording

8.12  Notices

8.13  When Lease Becomes Binding

8.14  Section Headings

8.15  Rights of Mortgagee

8.16  Status Report and Financial Statements

8.17  Self-Help

8.18  Holding Over

8.19  Non-Subrogation

8.20  Intentionally Omitted

8.21  Security Deposit

8.22  Late Payment

8.23  Governing Law

8.24  Additional Rent


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                                   ARTICLE II

                        BUILDING, PREMISES, TERM AND RENT

2.1   Landlord hereby demises and leases to Tenant, and Tenant hereby hires and
      accepts from Landlord, Tenant's Space in the Building excluding exterior
      faces of exterior walls, the common stairways and stairwells, elevators
      and elevator wells, fan rooms, electric and telephone closets, janitor
      closets, freight elevator vestibules, and pipes, ducts, conduits, wires
      and appurtenant fixtures serving exclusively or in common other parts of
      the Building and if Tenant's Space includes less than the entire rentable
      area of any floor, excluding the common corridors, elevator lobbies and
      toilets located on such floor.

      Tenant's Space with such exclusions is hereinafter sometimes referred to
      as the "Premises". The term "Building" means the Building identified on
      the first page, and which is the subject of this Lease and being one of
      the two (2) Buildings erected on the Site by the Landlord; the term "Site"
      means all, and also any part, of the Land described in Exhibit A, plus any
      additions or reductions thereto resulting from the change of any abutting
      street line and all parking areas and structures. The terms "Property" or
      "Complex" means the two (2) Buildings and the Site.

2.1.1 Tenant hereby agrees with Landlord that, upon the request of Landlord made
      from time to time, Tenant shall relocate from the Premises then demised to
      Tenant under this Lease (the "Original Premises") to other premises (the
      "Relocated Premises") within the Building and upon such relocation the
      Relocated Premises shall become the premises demised under this Lease and
      wherever the term "Premises" is used herein the same thereafter shall mean
      and refer to the Relocated Premises. Landlord, at its sole cost and
      expense, shall perform the partitioning of the Relocated Premises and
      shall place the same into substantially equivalent condition to that in
      which the Original Premises were in prior to such relocation, and Landlord
      shall also reimburse Tenant for Tenant's reasonable out-of-pocket moving
      expenses in so relocating to the Relocated Premises upon billing therefor
      from Tenant, which billing shall include reasonable evidence thereof in
      the form of paid invoices, receipts and the like. Tenant shall not be
      required to vacate the Original Premises and to relocate to the Relocated
      Premises until the Relocated Premises shall be substantially complete
      subject to punch list items and items of long lead time. Upon any such
      relocation the Tenant shall enter into an amendment to this Lease
      confirming such relocation, but the Tenant's failure to enter into such
      amendment shall not affect in any manner the relocation of the Premises
      demised under this Lease from the Original Premises to the Relocated
      Premises.


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2.2   Subject to Landlord's right to change or alter any of the following in
      Landlord's discretion as herein provided, Tenant shall have, as
      appurtenant to the Premises, the non-exclusive right to use in common with
      others, but not in a manner or extent that would materially interfere with
      the normal operation and use of the Building as a multi-tenant office
      building and 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: (a) the common lobbies, corridors, stairways, and
      elevators of the Building, and the pipes, ducts, shafts, conduits, wires
      and appurtenant meters and equipment serving the Premises in common with
      others, (b) the loading areas serving the Building and the common walkways
      and driveways necessary for access to the Building, and (c) if the
      Premises include less than the entire rentable floor area of any floor,
      the common toilets, corridors and elevator lobby of such floor.
      Notwithstanding anything to the contrary herein, Landlord has no
      obligation to allow any particular telecommunication service provider to
      have access to the Building or the Premises. If Landlord permits such
      access, Landlord may condition such access upon the payment to Landlord by
      the service provider of fees assessed by Landlord in its sole discretion.

      2.2.1 In addition, Landlord shall provide to Tenant monthly privileges in
            the number specified in Section 1.1 for the parking of automobiles,
            in common with use by other tenants from time to time of the
            Complex, and on a first-come, first-served basis, and Landlord shall
            not be obligated to furnish stalls or spaces on the Site
            specifically designated for Tenant's use. Tenant covenants and
            agrees that it and all persons claiming by, through and under it,
            shall at all times abide by all reasonable rules and regulations
            promulgated by Landlord with respect to the use of the parking areas
            on the Site. The parking privileges granted herein are
            non-transferable except to a permitted assignee or subtenant as
            provided in Section 5.6 through Section 5.6.5. Further, Landlord
            assumes no responsibility whatsoever for loss or damage due to fire,
            theft or otherwise to any automobile(s) parked on the Site or to any
            personal property therein, however caused, and Tenant covenants and
            agrees, upon request from Landlord from time to time, to notify its
            officers, employees, agents and invitees of such limitation of
            liability. Tenant acknowledges and agrees that a license only is
            hereby granted, and no bailment is intended or shall be created.

2.3   Landlord reserves the right from time to time, without unreasonable
      interference with Tenant's use: (a) to install, use, maintain, repair,
      replace and relocate for service to the Premises and other parts of the
      Building, or either, pipes, ducts, conduits, wires and appurtenant
      fixtures, wherever located in the Premises or Building, and (b) to alter
      or relocate any other common facility, provided that substitutions are
      substantially equivalent or better. Installations, replacements and
      relocations referred to in clause (a) above shall be located so far as
      practicable in


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      the central core area of the Building, above ceiling surfaces, below floor
      surfaces or within perimeter walls of the Premises. Except in the case of
      emergencies, Landlord agrees to use its best efforts to give Tenant
      reasonable advance notice of any of the foregoing activities which require
      work in the Premises.

2.4   The Term of this Lease shall be the period specified in Section 1.1 hereof
      as the "Lease Term", unless sooner terminated or extended as herein
      provided. If Section 1.1 provides for a fixed Commencement Date, then the
      Commencement Date of the Lease Term hereof shall be such date. Otherwise,
      the Lease Term hereof shall commence on, and the Commencement Date shall
      be the day on which the Premises are delivered by Landlord to Tenant.

      In the case where the Premises are to be delivered in their AS-IS
      condition, the day on which the Premises are delivered by Landlord to
      Tenant shall be the date on which the Landlord delivers the Premises to
      Tenant free and clear of all other tenants and occupants.

      As soon as may be convenient after the Commencement Date has been
      determined, Landlord and Tenant agree to join with each other in the
      execution, in the form of Exhibit E hereto, of a written Commencement Date
      Agreement in which the Commencement Date and specified Lease Term of this
      Lease shall be stated. If Tenant shall fail to execute such Agreement, the
      Commencement Date and Lease Term shall be as reasonably determined by
      Landlord in accordance with the terms of this Lease.

2.5   Tenant agrees to a to Landlord, or as directed by Landlord, at P.O. Box
      3557, Boston. MA 02241-3557 or at such other place as Landlord shall from
      time to time designate by notice, on the Rent Commencement Date (defined
      in Section 1.1 hereof) and thereafter monthly, in advance, on the first
      day of each and every calendar month during the Original Term, a sum equal
      to one twelfth (1/12th) of the Annual Fixed Rent (sometimes hereinafter
      referred to as "fixed rent") and on the first day of each and every
      calendar month during the extension option period (if exercised), a sum
      equal to one twelfth (1/12th) of the annual fixed rent as determined in
      Section 8.20 for the applicable extension option period

      Annual Fixed Rent for any partial month shall be paid by Tenant to
      Landlord at such rate on a pro rata basis, and, if the Rent Commencement
      Date is a day other than the first day of a calendar month, the first
      payment which Tenant shall make to Landlord shall be a payment equal to a
      proportionate part of such monthly Annual Fixed Rent for the partial month
      from the Rent Commencement Date to the first day of the succeeding
      calendar month.


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      Other charges payable by Tenant on a monthly basis, as hereinafter
      provided, likewise shall be prorated, and the first payment on account
      thereof shall be determined in similar fashion but shall commence on the
      Rent Commencement Date; and other provisions of this Lease calling for
      monthly payments shall be read as incorporating this undertaking by
      Tenant.

      The Annual Fixed Rent and all other charges for which provision is herein
      made shall be paid by Tenant to Landlord, without offset, deduction or
      abatement except as otherwise specifically set forth in this Lease.

2.6   "Landlord's Operating Expenses" means the cost of operation of the
      Building and the Site which shall exclude costs of special services
      rendered to tenants (including Tenant) for which a separate charge is
      made, but shall include, without limitation, the following: premiums for
      insurance carried with respect to the Building and the Site (including,
      without limitation, liability insurance, insurance against loss in case of
      fire or casualty and insurance of monthly installments of fixed rent and
      any additional rent which may be due under this Lease and other leases of
      space in the Building for not more than 12 months in the case of both
      fixed rent and additional rent and if there be any first mortgage of the
      Property, including such insurance as may be required by the holder of
      such first mortgage); compensation and all fringe benefits, workmen's
      compensation insurance premiums and payroll taxes paid to, for or with
      respect to all persons engaged in the operating, maintaining, managing,
      insuring or cleaning of the Building or Site, water, sewer, electric, gas,
      oil and telephone charges (excluding heating, ventilating and air
      conditioning, electricity and utility charges separately chargeable to
      tenants); cost of building and cleaning supplies and equipment; cost of
      maintenance, cleaning and repairs (other than repairs not properly
      chargeable against income or reimbursed from contractors under
      guarantees); cost of snow removal and care of landscaping; payments under
      service contracts with independent contractors; payments by the Landlord
      to the town in which the Complex is located relating to traffic safety,
      fire safety, and other governmental services and programs; management fees
      at reasonable rates consistent with the type of occupancy and the service
      rendered; and all other reasonable and necessary expenses paid in
      connection with the operation, cleaning, management, insuring and
      maintenance of the Building and the Site and properly chargeable against
      income; provided, however, there shall be included (a) depreciation for
      capital expenditures made by Landlord (i) to reduce operating expenses if
      Landlord shall have reasonably determined that the annual reduction in
      operating expenses shall exceed depreciation therefor or (ii) to comply
      with applicable laws, rules, regulations, requirements, statutes,
      ordinances, by-laws and court decisions of all public authorities which
      are now or hereafter in force (herein collectively called "Legal
      Requirements"); plus (b) in the case of both (i) and (ii) an interest
      factor, reasonably determined by Landlord, as being the interest rate then
      charged for long term mortgages by institutional lenders on like
      properties within the


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      locality in which the Building is located; depreciation in the case of
      both (i) and (ii) shall be determined by dividing the original cost of
      such capital expenditure by the number of years of useful life of the
      capital item acquired and 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 further provided, however, if Landlord reasonably concludes on the
      basis of engineering estimates that a particular capital expenditure will
      effect savings in other Operating Expenses, including, without limitation,
      energy related costs, and that such projected savings will, on an annual
      basis ("Projected Annual Savings"), exceed the annual depreciation
      therefor, then and in such event the amount of depreciation for such
      capital expenditure shall be increased to an amount equal to the Projected
      Annual Savings; and in such circumstance, the increased depreciation (in
      the amount of the Projected Annual Savings) shall be made for such period
      of time as it would take to fully amortize the cost of the item in
      question, together with interest thereon at the interest rate as aforesaid
      in equal monthly payments, each in the amount of 1/12th of the Projected
      Annual Savings, with such payment to be applied first to interest and the
      balance to principal.

      "Operating Expenses Allocable to the Premises" shall mean (a) the same
      proportion of Landlord's Operating Expenses for and pertaining to the
      Building as the Rentable Floor Area of Tenant's Space bears to the Total
      Rentable Floor Area of the Building plus (b) the same proportion of
      Landlord's Operating Expenses for and pertaining to the Site as the
      Rentable Floor Area of Tenant's Space bears to the Total Rentable Floor
      Area of the Buildings.

      "Base Operating Expenses" is hereinbefore defined in Section 1.1.

      "Base Operating Expenses Allocable to the Premises" means (i) the same
      proportion of Base Operating Expenses for and pertaining to the Building
      as the Rentable Floor Area of Tenant's Space bears to the Rentable Floor
      Area of the Building plus (ii) the same proportion of Base Operating
      Expenses for and pertaining to the Site as the Rentable Floor Area of
      Tenant's Space bears to the Rentable Floor Area of the Buildings.

      If with respect to any calendar year falling within the Term, or fraction
      of a calendar year falling within the Term at the beginning or end
      thereof, the Operating Expenses Allocable to the Premises (a) for a full
      calendar year exceed Base Operating Expenses Allocable to the Premises, or
      for any such fraction of a calendar year exceed the corresponding fraction
      of Base Operating Expenses Allocable to the Premises, or (b) for a full
      calendar year are less than Base Operating Expenses Allocable to the
      Premises, or for any such fraction of a calendar year are less than the
      corresponding fraction of Base Operating Expenses Allocable to the
      Premises then, in the case of (a) Tenant shall pay to Landlord, as
      Additional Rent, the amount of such excess, or in the case of (b) Landlord
      shall


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      credit eighty percent (80%) of such difference against monthly
      installments of fixed rent next thereafter coming due or against any sums
      then due from Tenant to Landlord under this Lease (or refund such eighty
      percent (80%) if the Term has ended and Tenant has no further obligation
      to Landlord). Such payments shall be made at the times and in the manner
      hereinafter provided in this Section 2.6. The Base Operating Expenses
      Allocable to the Premises do not include any costs in respect of
      electricity and HVAC, provision for the payment of which is made in
      Section 2.8 of this Lease.

      Not later than one hundred twenty (120) days after the end of the first
      calendar year or fraction thereof ending December 31 and of each
      succeeding calendar year during the Term or fraction thereof at the end of
      the Term, Landlord shall render Tenant a statement in reasonable detail
      and according to usual accounting practices certified by a representative
      of Landlord, showing for the preceding calendar year or fraction thereof,
      as the case may be, Landlord's Operating Expenses and Operating Expenses
      Allocable to the Premises. Said statement to be rendered to Tenant shall
      also show for the preceding year or fraction thereof as the case may be
      the amounts of operating expenses already paid by Tenant as additional
      rent, and the amount of operating expenses remaining due from, or overpaid
      by, Tenant for the year or other period covered by the statement. Within
      thirty (30) days after the date of delivery of such statement, Tenant
      shall pay to Landlord the balance of the amounts, if any, required to be
      paid pursuant to the above provisions of this Section 2.6 with respect to
      the preceding year or fraction thereof, or Landlord shall credit any
      amounts due from it to Tenant pursuant to the above provisions of this
      Section 2.6 against (i) monthly installments of fixed rent next thereafter
      coming due or (ii) any sums then due from Tenant to Landlord under this
      Lease (or refund such portion of the overpayment as aforesaid if the Term
      has ended and Tenant has no further obligation to Landlord).

      In addition, Tenant shall make payments monthly on account of Tenant's
      share of increases in Landlord's Operating Expenses anticipated for the
      then current year at the time and in the fashion herein provided for the
      payment of Annual Fixed Rent. The amount to be paid to Landlord shall be
      an amount reasonably estimated annually by Landlord to be sufficient to
      cover, in the aggregate, a sum equal to Tenant's share of such increases
      in Landlord's Operating Expenses for each calendar year during the Term.

      Notwithstanding the foregoing provisions, no decrease in Landlord's
      Operating Expenses shall result in a reduction of the amount otherwise
      payable by Tenant if and to the extent said decrease is attributable to
      vacancies in the Buildings rather than to any other causes.

2.7   If with respect to any full Tax Year or fraction of a Tax Year falling
      within the Term, Landlord's Tax Expenses Allocable to the Premises as
      hereinafter defined


                                      -13-
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      (a) for a full Tax Year exceed Base Taxes Allocable to the Premises, or
      for any such fraction of a Tax Year exceed the corresponding fraction of
      Base Taxes Allocable to the Premises, or (b) for a full Tax Year
      subsequent to the date of full assessment are less than Base Taxes
      Allocable to the Premises, or for any such fraction of a Tax Year
      subsequent to the date of full assessment are less than the corresponding
      fraction of Base Taxes Allocable to the Premises; then, on or before the
      thirtieth (30th) day following receipt by Tenant of the certified
      statement referred to below in this Section 2.7, in the case of (a) Tenant
      shall pay to Landlord, as Additional Rent, the amount of such excess, or
      in the case of (b) Landlord shall credit such difference against monthly
      installments of fixed rent next thereafter coming due (or refund such
      overpayment if the Term has ended and Tenant has no further obligation to
      Landlord). In addition, payments by Tenant on account of increases in real
      estate taxes anticipated for the then current year shall be made monthly
      at the time and in the fashion herein provided for the payment of fixed
      rent. The amount so to be paid to Landlord shall be an amount reasonably
      estimated by Landlord to be sufficient to provide Landlord, in the
      aggregate, a sum equal to Tenant's share of such increases, at least ten
      (10) days before the day on which such payments by Landlord would become
      delinquent. Not later than one hundred twenty (120) days after Landlord's
      Tax Expenses Allocable to the Premises are determined for the first such
      Tax Year or fraction thereof and for each succeeding Tax Year or fraction
      thereof during the Term, Landlord shall render Tenant a statement in
      reasonable detail certified by a representative of Landlord showing for
      the preceding year or fraction thereof, as the case may be, real estate
      taxes on the Building and the Site and abatements and refunds of any taxes
      and assessments. Expenditures for legal fees and for other expenses
      incurred in obtaining the tax refund or abatement may be charged against
      the tax refund or abatement before the adjustments are made for the Tax
      Year.

      To the extent that real estate taxes shall be payable to the taxing
      authority in installments with respect to periods less than a Tax Year,
      the foregoing statement shall be rendered and payments made on account of
      such installments. Notwithstanding the foregoing provisions, no decrease
      in Landlord's Tax Expenses with respect to any Tax Year shall result in a
      reduction of the amount otherwise payable by Tenant if and to the extent
      said decrease is attributable to vacancies in the Building or partial
      completion of the Building rather than to any other causes.

      Terms used herein are defined as follows:

      (i)   "Tax Year" means the twelve-month period beginning July 1 each year
            during the Term or if the appropriate governmental tax fiscal period
            shall begin on any date other than July 1, such other date. If
            during the Lease Term the Tax Year is changed by applicable law to
            less than a full 12-


                                      -14-
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            month period, the Base Taxes and Base Taxes Allocable to the
            Premises shall each be proportionately reduced.

      (ii)  "Landlord's Tax Expenses Allocable to the Premises" shall mean (a)
            the same proportion of Landlord's Tax Expenses for and pertaining to
            the Building as the Rentable Floor Area of Tenant's Space bears to
            the Total Rentable Floor Area of the Building plus (b) the same
            proportion of Landlord's Tax Expenses for and pertaining to the Site
            as the Rentable Floor Area of Tenant's Space bears to the Total
            Rentable Floor Area of the Buildings.

      (iii) "Landlord's Tax Expenses" with respect to any Tax Year means the
            aggregate real estate taxes on the Building and Site with respect to
            that Tax Year, reduced by any abatement receipts with respect to
            that Tax Year.

      (iv)  "Base Taxes" is hereinbefore defined in Section 1.1.

      (v)   "Base Taxes Allocable to the Premises" means (i) the same proportion
            of Base Taxes for and pertaining to the Building as the Rentable
            Floor Area of Tenant's Space bears to the Total Rentable Floor Area
            of the Building, plus (ii) the same proportion of Base Taxes for and
            pertaining to the Site as the Rentable Floor Area of Tenant's Space
            bears to the Total Rentable Floor Area of the Buildings.

      (vi)  "Real estate taxes" means all taxes and special assessments of every
            kind and nature assessed by any governmental authority on the
            Building or Site which the Landlord shall become obligated to pay
            because of or in connection with the ownership, leasing and
            operation of the Site, the Building and the Property (including
            without limitation, if applicable, the excise prescribed by Mass
            Gen. Laws (Ter Ed) Chapter 121A, Section 10 and amounts in excess
            thereof paid to the City of Waltham pursuant to agreement between
            Landlord and the City) and reasonable expenses of any proceedings
            for abatement of taxes. The amount of special taxes or special
            assessments to be included shall be limited to the amount of the
            installment (plus any interest, other than penalty interest, payable
            thereon) of such special tax or special assessment required to be
            paid during the year in respect of which such taxes are being
            determined. There shall be excluded from such taxes all income,
            estate, succession, inheritance and transfer taxes; provided,
            however, that if at any time during the Term the present system of
            ad valorem taxation of real property shall be changed so that in
            lieu of the whole or any part of the ad valorem tax on real property
            there shall be assessed on Landlord a capital levy or other tax on
            the gross rents received with respect to the Site or Building or
            Property, or a federal,


                                      -15-
<PAGE>

            state, county, municipal, or other local income, franchise, excise
            or similar tax, assessment, levy or charge distinct from any now in
            effect in the jurisdiction in which the Property is located)
            measured by or based, in whole or in part, upon any such gross
            rents, then any and all of such taxes, assessments, levies or
            charges, to the extent so measured or based, shall be deemed to be
            included within the term "real estate taxes" but only to the extent
            that the same would be payable if the Site and Buildings were the
            only property of Landlord.

2.8   Tenant shall pay to Landlord, as Additional Rent, Tenant's Proportionate
      Share (hereinafter defined) of the cost incurred by the Landlord in
      furnishing electricity and heating, ventilating and air conditioning
      ("HVAC") to the Building and the Site, including common areas and
      facilities and space occupied by tenants, (but expressly excluding utility
      charges separately chargeable to tenants for additional or special
      services), and Tenant shall pay on account thereof, at the time that
      monthly installments of Annual Fixed Rent are due and payable, as
      Additional Rent, an amount equal to 1/12th (prorated for any partial
      month) of the amount estimated by Landlord from time to time as the
      Tenant's Proportionate Share of the annual cost thereof. If with respect
      to any calendar year falling within the Term or fraction of a calendar
      year falling within the Term at the beginning or end thereof, the Tenant's
      Proportionate Share of the cost of furnishing electricity and HVAC to the
      Building and the Site exceeds the amounts payable on account thereof, then
      Tenant shall pay to Landlord, as Additional Rent, on or before the
      thirtieth (30th) day following receipt by Tenant of the statement referred
      to below in this Section 2.8, Tenant's Proportionate Share of the amount
      of such excess. For and with respect to the electricity and HVAC of the
      Building, the Tenant's Proportionate Share shall be a fraction, the
      numerator of which is the Rentable Floor Area of Tenant's Space and the
      denominator of which is the Total Rentable Floor Area of the Building, and
      for and with respect to the electricity for the Site the Tenant's
      Proportionate Share shall be a fraction, the numerator of which is the
      Rentable Floor Area of Tenant's Space and the denominator of which is the
      Total Rentable Floor Area of the Buildings.

      Not later than one hundred twenty (120) days after the end of the first
      calendar year or fraction thereof ending December 31 and of each
      succeeding calendar year during the Term or fraction thereof at the end of
      the Term, Landlord shall render Tenant a reasonably detailed accounting
      certified by a representative of Landlord showing for the preceding
      calendar year, or fraction thereof, as the case may be, the costs of
      furnishing electricity and HVAC to the Building and the Site. Said
      statement to be rendered to Tenant also shall show for the preceding year
      or fraction thereof, as the case may be, the amount already paid by Tenant
      on account of electricity and HVAC, and the amount remaining due from, or
      overpaid by, Tenant for the year or other period covered by the statement.


                                      -16-
<PAGE>

                                  ARTICLE III

                  CONDITION OF PREMISES; ALTERATIONS BY TENANT

3.1   SUBSTANTIAL COMPLETION.

      (A) Tenant shall accept the Premises in their AS-IS condition without any
      obligation on the Landlord's part to perform any additions, alterations,
      improvements, demolition or other work therein or pertaining thereto.
      Tenant, at its sole cost and expense, shall perform all work necessary to
      prepare the Premises for Tenant's occupancy in accordance with plans and
      specifications prepared by an architect, licensed by the Commonwealth of
      Massachusetts and reasonably approved by Landlord, such plans and
      specifications to be subject to the reasonable approval of the Landlord.
      Tenant shall submit to Landlord a detailed floor plan layout together with
      working drawings (the "Tenant's Submission") for work to be performed by
      Tenant to prepare the Premises for Tenant's occupancy. Such floor plan
      layout and working drawings (the "Plans") shall contain at least the
      information required by, and shall conform to the requirements of, Exhibit
      B. Provided that the Plans contain at least the information required by,
      and conform to the requirements of, said Exhibit B, Landlord's approval of
      the Plans shall not be unreasonably withheld or delayed; however,
      Landlord's determination of matters relating to aesthetic issues relating
      to alterations or changes which are visible outside the Premises shall be
      in Landlord's sole discretion. If Landlord disapproves of any Plans, then
      Tenant shall promptly have the Plans revised by its architect to
      incorporate all objections and conditions presented by Landlord and shall
      resubmit such plans to Landlord no later than five (5) days after Landlord
      has submitted to Tenant its objections and conditions. Such process shall
      be followed until the Plans shall have been approved by the Landlord
      without objection or condition.

      Once the Plans have been approved by Landlord, Tenant, at its sole cost
      and expense, shall promptly, and with all due diligence, perform the work
      necessary to prepare the Premises for Tenant's occupancy as set forth on
      the Plans, and, in connection therewith, the Tenant shall obtain all
      necessary governmental permits and approvals for such work. All of such
      work shall be performed strictly in accordance with the Plans and in
      accordance with applicable Legal Requirements (as defined in Section 3.3
      hereof) and Insurance Requirements (as defined in Section 3.3 hereof).
      Tenant shall have such work performed by contractors, reasonably approved
      by Landlord, which contractors shall provide to Landlord such insurance as
      the Landlord may reasonably require. Landlord shall have the right to
      provide such rules and regulations relative to the performance of such
      work and any other work which the Tenant may perform under this Lease and
      Tenant shall abide by all such reasonable rules and regulations and shall
      cause all of its contractors to so abide. It shall be Tenant's obligation
      to obtain a certificate


                                      -17-
<PAGE>

      of occupancy or other like governmental approval for the use and occupancy
      of the Premises, and Tenant shall not open for business in the Premises
      until and unless it has obtained such approval and has submitted to
      Landlord a copy of the same together with waivers of lien from all of
      Tenant's contractors in form adequate for recording purposes. Tenant shall
      also prepare and submit to Landlord promptly after the Tenant's work is
      substantially complete a set of as-built plans showing the work performed
      by Tenant to the Premises.

3.2   Intentionally Omitted.

3.3   This Section 3.3 shall apply before and during the Term. All construction
      work required or permitted by this Lease shall be done in a good and
      workmanlike manner and in compliance with all applicable laws, ordinances,
      rules, regulations, statutes, by-laws, court decisions, and orders and
      requirements of all public authorities ("Legal Requirements") and all
      Insurance Requirements (as defined in this Section 3.3 hereof). All of
      Tenant's work shall be coordinated with any work being performed by or for
      Landlord and in such manner as to maintain harmonious labor relations.
      Each party may inspect the work of the other at reasonable times and shall
      promptly give notice of observed defects. Each party authorizes the other
      to rely in connection with design and construction upon approval and other
      actions on the party's behalf by any Construction Representative of the
      party named in Section 1.1 or any person hereafter designated in
      substitution or addition by notice to the party relying. Tenant shall not
      make alterations and additions to Tenant's space except in accordance with
      plans and specifications therefor first approved by Landlord, which
      approval shall not be unreasonably withheld. However, Landlord's
      determination of matters relating to aesthetic issues relating to
      alterations, additions or improvements which are visible outside the
      Premises shall be in Landlord's sole discretion. Without limiting such
      standard Landlord shall not be deemed unreasonable for withholding
      approval of any alterations or additions (including, without limitation,
      any alterations or additions to be performed by Tenant under Section 3.1)
      which (a) involve or, in Landlord's opinion, might affect any structural
      or exterior element of the Building, any area or element outside of the
      Premises, or any facility serving any area of the Building outside of the
      Premises, or (b) will delay completion of the Premises or Building, or (c)
      will require unusual expense to readapt the Premises to normal office use
      on Lease termination or increase the cost of construction or of insurance
      or taxes on the Building or of the services called for by Section 4.1
      unless Tenant first gives assurance acceptable to Landlord for payment of
      such increased cost and that such readaptation will be made prior to such
      termination without expense to Landlord, or (d) are inconsistent, in
      Landlord's judgment, with alterations satisfying Landlord's standards for
      new alterations in the Building. Landlord's review and approval of any
      such plans and specifications and consent to perform work described
      therein shall not be deemed an agreement by Landlord that such plans,


                                      -18-
<PAGE>

      specifications and work conform with applicable Legal Requirements and
      requirements of insurers of the Building (herein called "Insurance
      Requirements") nor deemed a waiver of Tenant's obligations under this
      Lease with respect to applicable Legal Requirements and Insurance
      Requirements nor impose any liability or obligation upon Landlord with
      respect to the completeness, design sufficiency or compliance of such
      plans, specifications and work with applicable Legal Requirements and
      Insurance Requirements. All alterations and additions shall be part of the
      Building unless and until Landlord shall specify the same for removal
      pursuant to Section 5.2. All of Tenant's alterations and additions and
      installation of furnishings shall be coordinated with any work being
      performed by Landlord and in such manner as to maintain harmonious labor
      relations and not to damage the Buildings or Site or interfere with
      construction or operation of the Buildings and other improvements to the
      Site and, except for installation of furnishings, shall be performed by
      Landlord's general contractor or by contractors or workmen first approved
      by Landlord. Except for work by Landlord's general contractor, Tenant,
      before its work is started, shall secure all licenses and permits
      necessary therefor; 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 security satisfactory to Landlord
      protecting Landlord against liens arising out of the furnishing of such
      labor and material; and cause each contractor to carry workmen's
      compensation insurance in statutory amounts covering all the contractor's
      and subcontractor's employees and commercial general liability insurance
      or comprehensive general liability insurance with a broad form
      comprehensive liability endorsement with such limits as Landlord may
      reasonably require, but in no event less than $5,000,000.00 combined
      single limit per occurrence on a per location basis (all such insurance to
      be written in companies approved by Landlord and naming and insuring
      Landlord and Landlord's managing agent as additional insureds and insuring
      Tenant as well as the contractors), and to deliver to Landlord
      certificates of all such insurance. Tenant agrees to pay promptly when due
      the entire cost of any work done on the Premises by Tenant, its agents,
      employees, or independent contractors, and not to cause or permit any
      liens for labor or materials performed or furnished in connection
      therewith to attach to the Premises or the Buildings or the Site and
      immediately to discharge any such liens which may so attach. Tenant shall
      pay, as additional rent, 100% of any real estate taxes on the Complex
      which shall, at any time after commencement of the Term, result from any
      alteration, addition or improvement to the Premises made by Tenant.

3.4   All construction work required or permitted by this Lease shall be done in
      a good and workmanlike manner and in compliance with all applicable Legal
      Requirements and Insurance Requirements now or hereafter in force. Each
      party may inspect the work of the other at reasonable times and shall
      promptly give notice of observed defects.


                                      -19-
<PAGE>

                                   ARTICLE IV

                 LANDLORD'S COVENANTS; INTERRUPTIONS AND DELAYS

4.1   Landlord covenants:

      4.1.1 To furnish services, utilities, facilities and supplies set forth in
            Exhibit C equal to those customarily provided by landlords in high
            quality buildings in the Boston West Suburban Market subject to
            escalation reimbursement in accordance with Section 2.6.

      4.1.2 To furnish, at Tenant's expense, reasonable additional Building
            operation services which are usual and customary in similar office
            buildings in the Boston West Suburban Market upon reasonable advance
            request of Tenant at reasonable and equitable rates from time to
            time established by Landlord.

      4.1.3 Subject to the escalation provisions of Section 2.6 and except as
            otherwise provided in Article VI, (i) to make such repairs to the
            roof, exterior walls, floor slabs and common areas and facilities as
            may be necessary to keep them in serviceable condition and (ii) to
            maintain the Building (exclusive of Tenant's responsibilities under
            this Lease) in a first class manner comparable to the maintenance of
            similar properties in the Boston West Suburban Market.

      4.1.4 To provide and install, at Landlord's expense for the initial
            installation (all changes thereafter at Tenant's expense), letters
            or numerals on doors in the Premises to identify Tenant's official
            name and Building address; all such letters and numerals shall be in
            the building standard graphics and no others shall be used or
            permitted on the Premises.

4.2   Landlord shall not be liable to Tenant for any compensation or reduction
      of rent by reason of inconvenience or annoyance or for loss of business
      arising from the necessity of Landlord or its agents entering the Premises
      for any of the purposes in this Lease authorized, or for repairing the
      Premises or any portion of the Building or Site however the necessity may
      occur. In case Landlord is prevented or delayed from making any repairs,
      alterations or improvements, or furnishing any services or performing any
      other covenant or duty to be performed on Landlord's part by reason of any
      cause reasonably beyond Landlord's control, including without limitation
      strike, lockout, breakdown, accident, order or regulation of or by any
      Governmental authority, or failure of supply, or inability by the exercise
      of reasonable diligence to obtain supplies, parts or employees necessary
      to furnish such services, or because of war or other emergency, or for any
      cause due to any act or neglect of Tenant or Tenant's servants, agents,


                                      -20-
<PAGE>

      employees, licensees or any person claiming by, through or under Tenant,
      or other causes reasonably beyond Landlord's control, Landlord shall not
      be liable to Tenant therefor, nor, except as expressly otherwise provided
      in Article VI, shall Tenant be entitled to any abatement or reduction of
      rent by reason thereof, nor shall the same give rise to a claim in
      Tenant's favor that such failure constitutes actual or constructive, total
      or partial, eviction from the Premises.

      Landlord reserves the right to stop any service or utility system, when
      necessary by reason of accident or emergency, or until necessary repairs
      have been completed; provided, however, that in each instance of stoppage,
      Landlord shall exercise reasonable diligence to eliminate the cause
      thereof. Except in case of emergency repairs, Landlord will give Tenant
      reasonable advance notice of any contemplated stoppage and will use
      reasonable efforts to avoid unnecessary inconvenience to Tenant by reason
      thereof.

                                    ARTICLE V

                               TENANT'S COVENANTS

      Tenant covenants during the term and such further time as Tenant occupies
any part of the Premises:

5.1   To pay when due all fixed rent and additional rent and all charges for
      utility services rendered to the Premises (except as otherwise provided in
      Exhibit C) and, as further additional rent, all charges for additional
      services rendered pursuant to Section 4.1.2.

5.2   Except as otherwise provided in Article VI and Section 4.1.3 to keep the
      Premises in good order, repair and condition, reasonable wear and tear
      only excepted, and all glass in windows (except glass in exterior walls
      unless the damage thereto is attributable to Tenant's negligence or
      misuse) and doors of the Premises whole and in good condition with glass
      of the same type and quality as that injured or broken, damage by fire or
      taking under the power of eminent domain only excepted, and at the
      expiration or termination of this Lease peaceably to yield up the Premises
      all construction, work, improvements, and all alterations and additions
      thereto in good order, repair and condition, reasonable wear and tear only
      excepted, first removing all goods and effects of Tenant and, to the
      extent specified by Landlord by notice to Tenant given at least ten (10)
      days before such expiration or termination, the wiring for Tenant's
      computer, telephone and other communication systems and equipment and all
      alterations and additions made by Tenant and all partitions, and repairing
      any damage caused by such removal and restoring the Premises and leaving
      them clean and neat. Tenant shall not permit or commit any waste, and
      Tenant shall be responsible for the cost of repairs which may be made
      necessary by reason of damage to common areas in the Building, to


                                      -21-
<PAGE>

      the Site or to the other building caused by Tenant, Tenant's agents,
      employees, contractors, sublessees, licensees, concessionaires or
      invitees. Tenant shall maintain all its equipment, furniture and
      furnishings in good order and repair.

5.3   Continuously from the commencement of the Term to use and occupy the
      Premises for the Permitted Uses only, and not to injure or deface the
      Premises, Building, the Additional Building, the Site or any other part of
      the Complex nor to permit in the Premises or on the Site any auction sale,
      vending machine, or inflammable fluids or chemicals, or nuisance, or the
      emission from the Premises of any objectionable noise or odor, nor to use
      or devote the Premises or any part thereof for any purpose other than the
      Permitted Uses, nor any use thereof which is inconsistent with the
      maintenance of the Building as an office building of the first class in
      the quality of its maintenance, use and occupancy, or which is improper,
      offensive, contrary to law or ordinance or liable to invalidate or
      increase the premiums for any insurance on the Building or its contents or
      liable to render necessary any alteration or addition to the Building.
      Further, (i) Tenant shall not, nor shall Tenant permit its employees,
      invitees, agents, independent contractors, contractors, assignees or
      subtenants to, keep, maintain, store or dispose of (into the sewage or
      waste disposal system or otherwise) or engage in any activity which might
      produce or generate any substance which is or may hereafter be classified
      as a hazardous material, waste or substance (collectively "Hazardous
      Materials"), under federal, state or local laws, rules and regulations,
      including, without limitation, 42 U.S.C. Section 6901 et seq., 42 U.S.C.
      Section 9601 et seq., 42 U.S.C. Section 2601 et seq., 49 U.S.C. Section
      1802 et seq. and Massachusetts General Laws, Chapter 21E and the rules and
      regulations promulgated under any of the foregoing, as such laws, rules
      and regulations may be amended from time to time (collectively "Hazardous
      Materials Laws"), (ii) Tenant shall immediately notify Landlord of any
      incident in, on or about the Premises, the Building or the Site that would
      require the filing of a notice under any Hazardous Materials Laws, (iii)
      Tenant shall comply and shall cause its employees, invitees, agents,
      independent contractors, contractors, assignees and subtenants to comply
      with each of the foregoing and (iv) Landlord shall have the right to make
      such inspections (including testing) as Landlord shall elect from time to
      time to determine that Tenant is complying with the foregoing.

5.4   Not to obstruct in any manner any portion of the Building not hereby
      leased or any portion thereof or of the other building or of the Site used
      by Tenant in common with others; not without prior consent of Landlord to
      permit the painting or placing of any signs, curtains, blinds, shades,
      awnings, aerials or flagpoles, or the like, visible from outside the
      Premises; and to comply with all reasonable Rules and Regulations now or
      hereafter made by Landlord, of which Tenant has been given notice, for the
      care and use of the Building and Site and their facilities and approaches;
      Landlord shall not be liable to Tenant for the failure of other occupants
      of the Buildings to conform to such rules and regulations.


                                      -22-
<PAGE>

5.5   To keep the Premises equipped with all safety appliances required by any
      public authority because of any use made by Tenant other than normal
      office use, and to procure all licenses and permits so required because of
      such use and, if requested by Landlord, to do any work so required because
      of such use, it being understood that the foregoing provisions shall not
      be construed to broaden in any way Tenant's Permitted Use.

5.6   Except as otherwise expressly provided herein, Tenant covenants and agrees
      that it shall not assign, mortgage, pledge, hypothecate or otherwise
      transfer this Lease and/or Tenant's interest in this Lease or sublet
      (which term, without limitation, shall include granting of concessions,
      licenses or the like) the whole or any part of the Premises. Any
      assignment, mortgage, pledge, hypothecation, transfer or subletting not
      expressly permitted in or consented to by Landlord under Sections
      5.6.1-5.6.5 shall be void, ab initio; shall be of no force and effect; and
      shall confer no rights on or in favor of third parties. In addition,
      Landlord shall be entitled to seek specific performance of, and other
      equitable relief with respect to, the provisions hereof.

      5.6.1 Notwithstanding the foregoing provisions of Section 5.6 above and
            the provisions of Section 5.6.2 below, but subject to the provisions
            of Sections 5.6.3, 5.6.4 and 5.6.5, below Tenant shall have the
            right to assign this Lease or to sublet the Premises (in whole or in
            part) to any parent or subsidiary corporation of Tenant or to any
            corporation into which Tenant may be converted or with which it may
            merge, provided that the entity to which this Lease is so assigned
            or which so sublets the Premises has a credit worthiness (e.g.
            assets on a pro forma basis using generally accepted accounting
            principles consistently applied and using the most recent financial
            statements) which is the same or better than the Tenant as of the
            Date of this Lease. If any parent or subsidiary corporation of
            Tenant to which this Lease is assigned or the Premises sublet (in
            whole or in part) shall cease to be such a parent or subsidiary
            corporation, such cessation shall be considered an assignment or
            subletting requiring Landlord's consent.

            5.6.1.1   Notwithstanding the provisions of Section 5.6 above, in
                      the event Tenant desires to assign this Lease or to sublet
                      the whole (but not part) of the Premises (no partial
                      subletting being permitted other than as provided in
                      Section 5.6.1), Tenant shall notify Landlord thereof in
                      writing and Landlord shall have the right at its sole
                      option, to be exercised within thirty (30) days after
                      receipt of Tenant's notice, to terminate this Lease as of
                      a date specified in a notice to Tenant, which date shall
                      not be earlier than sixty (60) days nor later than one
                      hundred and twenty (120) days after


                                      -23-
<PAGE>

                      Landlord's notice to Tenant; provided, however, that upon
                      the termination date as set forth in Landlord's notice,
                      all obligations relating to the period after such
                      termination date (but not those relating to the period
                      before such termination date) shall cease and promptly
                      upon being billed therefor by Landlord, Tenant shall make
                      final payment of all rent and additional rent due from
                      Tenant through the termination date. In the event that
                      Landlord shall not exercise its termination rights as
                      aforesaid, or shall fail to give any or timely notice
                      pursuant to this Section the provisions of Sections
                      5.6.2-5.6.5 shall be applicable. This Section 5.6.1.1
                      shall not be applicable to an assignment or sublease
                      pursuant to Section 5.6.1.

      5.6.2 Notwithstanding the provisions of Section 5.6 above but subject to
            the provisions of this Section 5.6.2 and the provisions of Sections
            5.6.3, 5.6.4 and 5.6.5 below, in the event that Landlord shall not
            have exercised the termination right as set forth in Section
            5.6.1.1, or shall have failed to give any or timely notice under
            Section 5.6.1.1, then for a period of ninety (90) days (i) after the
            receipt of Landlord's notice stating that Landlord does not elect
            the termination right, or (ii) after the expiration of the thirty
            (30) day period referred to in Section 5.6.1.1 in the event Landlord
            shall not give any or timely notice under Section 5.6.1.1, as the
            case may be, Tenant shall have the right to assign this Lease or
            sublet the whole (but not part) of the Premises in accordance with
            Tenant's notice to Landlord given as provided in Section 5.6.3
            provided that, in each instance, Tenant first obtains the express
            prior written consent of Landlord, which consent shall not be
            unreasonably withheld or delayed. Without limiting the foregoing
            standard, Landlord shall not be deemed to be unreasonably
            withholding its consent to such a proposed assignment or subleasing
            if:

            (a) the proposed assignee or subtenant is not of a character
            consistent with the operation of a first class office building (by
            way of example Landlord shall not be deemed to be unreasonably
            withholding its consent to an assignment or subleasing to any
            governmental agency), or

            (b) the proposed assignee or subtenant is not of good character and
            reputation, or

            (c) the proposed assignee or subtenant does not possess adequate
            financial capability to perform the Tenant obligations as and when
            due or required, or

            (d) the assignee or subtenant proposes to use the Premises (or part
            thereof) for a purpose other than the purpose for which the Premises
            may be used as stated in Section 1.1 hereof, or


                                      -24-
<PAGE>

            (e) the character of the business to be conducted or the proposed
            use of the Premises by the proposed subtenant or assignee shall (i)
            be likely to increase Landlord's Operating Expenses beyond that
            which Landlord now incurs for use by Tenant; (ii) be likely to
            increase the burden on elevators or other Building systems or
            equipment over the burden prior to such proposed subletting or
            assignment; or (iii) violate or be likely to violate any provisions
            or restrictions contained herein relating to the use or occupancy of
            the Premises, or

            (f) there shall be existing an Event of Default (defined in Section
            7.1) or

            (g) the proposed subtenant or assignee is a tenant or subtenant of
            any portion of the Property (or any entity affiliated or related to
            a tenant or subtenant of the Property) or is (or within the previous
            sixty (60) days has been) in active negotiation with Landlord or any
            affiliate of Landlord for other premises in the Site or in buildings
            nearby the Site.

      5.6.3 Tenant shall give Landlord prior notice of any proposed sublease or
            assignment, and said notice shall specify the provisions of the
            proposed assignment or subletting, including (a) the name and
            address of the proposed assignee or subtenant, (b) in the case of a
            proposed assignment or subletting pursuant to Section 5.6.2, such
            information as to the proposed assignee's or proposed subtenant's
            net worth and financial capability and standing as may reasonably be
            required for Landlord to make the determination referred to in
            Section 5.6.2 above (provided, however, that Landlord shall hold
            such information confidential having the right to release same to
            its officers, accountants, attorneys and mortgage lenders on a
            confidential basis), (c) all of the terms and provisions upon which
            the proposed assignment or subletting is to be made, (d) in the case
            of a proposed assignment or subletting pursuant to Section 5.6.2,
            all other information necessary to make the determination referred
            to in Section 5.6.2 above and (e) in the case of a proposed
            assignment or subletting pursuant to Section 5.6.1 above, such
            information as may be reasonably required by Landlord to determine
            that such proposed assignment or subletting complies with the
            requirements of said Section 5.6.1. No partial subletting shall be
            permitted.

            If Landlord shall consent to the proposed assignment or subletting,
            as the case may be, then, in such event, Tenant may thereafter
            sublease (the whole but (except in the case of a partial sublease
            under Section 5.6.1) not part of the Premises) or assign pursuant to
            Tenant's notice, as given hereunder; provided, however, that if such
            assignment or sublease shall


                                      -25-
<PAGE>

            not be executed and delivered to Landlord within ninety (90) days
            after the date of Landlord's consent, the consent shall be deemed
            null and void and the provisions of Section 5.6.1.1 shall be
            applicable.

      5.6.4 In addition, in the case of any assignment or subleasing as to which
            Landlord may consent (other than an assignment or subletting
            permitted under Section 5.6.1 hereof) such consent shall be upon the
            express and further condition, covenant and agreement, and Tenant
            hereby covenants and agrees that, in addition to the Annual Fixed
            Rent, additional rent and other charges to be paid pursuant to this
            Lease, one hundred percent (100%) of the "Assignment/Sublease
            Profits" (hereinafter defined), if any, shall be paid to Landlord.

            The "Assignment/Sublease Profits" shall be the excess, if any, of
            (a) the "Assignment/Sublease Net Revenues" as hereinafter defined
            over (b) the Annual Fixed Rent and additional rent and other charges
            provided in this Lease (provided, however, that for the purpose of
            calculating the Assignment/Sublease Profits in the case of a
            sublease, appropriate proportions in the applicable Annual Fixed
            Rent, additional rent and other charges under this Lease shall be
            made based on the percentage of the Premises subleased and on the
            terms of the sublease). The "Assignment/Sublease Net Revenues" shall
            be the fixed rent, additional rent and all other charges and sums
            payable either initially or over the term of the sublease or
            assignment plus all other profits and increases to be derived by
            Tenant as a result of such subletting or assignment, less the
            reasonable costs of Tenant incurred in such subleasing or assignment
            (the definition of which shall include but not necessarily be
            limited to rent concessions, brokerage commissions and alteration
            allowances) amortized over the term of the sublease or assignment.

            All payments of the Assignment/Sublease Profits due Landlord shall
            be made within ten (10) days of receipt of same by Tenant.

      5.6.5 (A) It shall be a condition of the validity of any assignment or
            subletting permitted under Section 5.6.1 above, or consented to
            under Section 5.6.2 above, that both Tenant and the assignee or
            sublessee agree directly with Landlord in a separate written
            instrument reasonably satisfactory to Landlord which contains terms
            and provisions reasonably required by Landlord, including, without
            limitation, the agreement of the assignee or sublessee to be bound
            by all the obligations of the Tenant hereunder, including, without
            limitation, the obligation to pay the rent and other amounts
            provided for under this Lease (but in the case of a partial
            subletting pursuant to Section 5.6.1, such subtenant shall agree on
            a pro rata basis to be so bound) including the provisions of
            Sections 5.6 through


                                      -26-
<PAGE>

            5.6.5 hereof, but such assignment or subletting shall not relieve
            the Tenant named herein of any of the obligations of the Tenant
            hereunder, Tenant shall remain fully and primarily liable therefor
            and the liability of Tenant and such assignee (or subtenant, as the
            case may be) shall be joint and several. Further, and
            notwithstanding the foregoing, the provisions hereof shall not
            constitute a recognition of the assignment or the assignee
            thereunder or the sublease or the subtenant thereunder, as the case
            may be, and at Landlord's option, upon the termination of the Lease,
            the assignment or sublease shall be terminated.

            (B) As Additional Rent, Tenant shall reimburse Landlord promptly for
            reasonable out of pocket legal and other expenses incurred by
            Landlord in connection with any request by Tenant for consent to
            assignment or subletting.

            (C) If this Lease be assigned, or if the Premises or any part
            thereof be sublet or occupied by anyone other than Tenant, Landlord
            may upon prior notice to Tenant, at any time and from time to time,
            collect rent and other charges from the assignee, sublessee or
            occupant and apply the net amount collected to the rent and other
            charges herein reserved, but no such assignment, subletting,
            occupancy or collection shall be deemed a waiver of this covenant,
            or a waiver of the provisions of Sections 5.6 through 5.6.5 hereof,
            or the acceptance of the assignee, sublessee or occupant as a tenant
            or a release of Tenant from the further performance by Tenant of
            covenants on the part of Tenant herein contained, the Tenant herein
            named to remain primarily liable under this Lease.

            (D) No an assignment or subletting under any of the provisions of
            Sections 5.6.1 or 5.6.2 shall in any way be construed to relieve
            Tenant from obtaining the express consent in writing to Landlord to
            any further assignment or subletting.

5.7   To defend with counsel first approved by Landlord (which approval shall
      not be unreasonably withheld or delayed), save harmless, and indemnify
      Landlord from any liability for injury, loss, accident or damage to any
      person or property, and from any claims, actions, proceedings and expenses
      and costs in connection therewith (including without limitation reasonable
      counsel fees) (i) arising from or claimed to have arisen from (a) the
      omission, fault, willful act, negligence or other misconduct of Tenant or
      Tenant's contractors, licensees, invitees, agents, servants, independent
      contractors or employees or (b) any use made or thing done or occurring on
      the Premises not due to the omission, fault, willful act, negligence or
      other misconduct of Landlord, or (ii) resulting from the failure of Tenant
      to perform and discharge its covenants and obligations under this Lease;
      to maintain commercial general liability insurance or comprehensive
      general liability


                                      -27-
<PAGE>

      insurance written on an occurrence basis with a broad form comprehensive
      liability endorsement covering the Premises insuring Landlord and
      Landlord's managing agent (and such persons as are in privity of estate
      with Landlord and Landlord's managing agent as may be set out in notice
      from time to time) as additional insureds as well as Tenant with limits
      which shall, at the commencement of the Term, be at least equal to those
      stated in Section 1.1 and from time to time during the Term shall be for
      such higher limits, if any, as are customarily carried in Greater Boston
      with respect to similar properties or which may reasonably be required by
      Landlord, and workmen's compensation insurance with statutory limits
      covering all of Tenant's employees working in the Premises, and to deposit
      with Landlord on or before the Commencement Date and concurrent with all
      renewals thereof, certificates for such insurance bearing the endorsement
      that the policies will not be canceled until after thirty (30) days'
      written notice to Landlord. All insurance required to be maintained by
      Tenant pursuant to this Lease shall be maintained with responsible
      companies qualified to do business, and in good standing, in the
      Commonwealth of Massachusetts and which have a rating of at least "A-" and
      are within a financial size category of not less than "Class VIII" in the
      most current Best's Key Rating Guide or such similar rating as may be
      reasonably selected by Landlord if such Guide is no longer published.

5.8   That 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 or elsewhere in the Building or on the Site, 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 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 such indemnity, hold harmless or exoneration is prohibited by law.
      Further, Tenant, at Tenant's expense, shall maintain at all times during
      the Term of this Lease insurance against loss or damage covered by the
      so-called "all risk" type insurance coverage with respect to Tenant's
      fixtures, equipment, goods, wares and merchandise, tenant improvements
      made by or paid for by Tenant, and other property of Tenant (collectively
      "Tenant's Property"). Such insurance shall be in an amount at least equal
      to the full replacement cost of Tenant's Property.

5.9   To permit Landlord and its agents to examine the Premises at reasonable
      times and, if Landlord shall so elect, to make any repairs or replacements
      Landlord may deem necessary; to remove, at Tenant's expense, any
      alterations, addition, signs, curtains, blinds, shades, awnings, aerials,
      flagpoles, or the like not consented to in


                                      -28-
<PAGE>

      writing; and to show the Premises to prospective tenants during the eleven
      (11) months preceding expiration of the Term and to prospective purchasers
      and mortgagees at all reasonable times.

5.10  Not to place a load upon the Premises exceeding an average rate of 70
      pounds of live load per square foot of floor area (partitions shall be
      considered as part of the live load); and not to move any safe, vault or
      other heavy equipment in, about or out of the Premises except in such
      manner and at such time as Landlord shall in each instance authorize;
      Tenant's business machines and mechanical equipment which cause vibration
      or noise that may be transmitted to the Building structure or to any other
      space in the Building shall be so installed, maintained and used by Tenant
      so as to eliminate such vibration or noise.

5.11  To pay promptly when due all taxes which may be imposed upon Tenant's
      Property in the Premises to whomever assessed.

5.12  To comply with all applicable Legal Requirements now or hereafter in force
      which shall impose a duty on Landlord or Tenant relating to or as a result
      of the use or occupancy of the Premises; provided that Tenant shall not be
      required to make any alterations or additions to the structure, roof,
      exterior and load bearing walls, foundation, structural floor slabs and
      other structural elements of the Building unless the same are required by
      such Legal Requirements as a result of or in connection with Tenant's use
      or occupancy of the Premises beyond normal use of space of this kind.
      Tenant shall promptly pay all fines, penalties and damages that may arise
      out of or be imposed because of its failure to comply with the provisions
      of this Section 5.12.

5.13  As Additional Rent, to pay all reasonable costs, counsel and other fees
      incurred by Landlord in connection with the successful enforcement by
      Landlord of any obligations of Tenant under this Lease or in connection
      with any bankruptcy case involving Tenant or any guarantor.

                                   ARTICLE VI

                               CASUALTY AND TAKING

6.1   In case during the Lease Term the Building is damaged by fire or casualty
      and such fire or casualty damage cannot, in the ordinary course,
      reasonably be expected to be repaired within one hundred twenty (120) days
      from the time that repair work would commence as reasonably determined by
      Landlord, Landlord may, at its election, terminate this Lease by notice
      given to Tenant within sixty (60) days after the date of such fire or
      other casualty, specifying the effective date of termination. The
      effective date of termination specified by Landlord shall not


                                      -29-
<PAGE>

      be less than thirty (30) days nor more than forty-five (45) days after the
      date of notice of such termination.

      In case during the last year of the Lease Term, the Premises are damaged
      by fire or casualty and such fire or casualty damage cannot, in the
      ordinary course, reasonably be expected to be repaired within one hundred
      fifty (150) days (and/or as to special work or work which requires long
      lead time then if such work cannot reasonably be expected to be repaired
      within such additional time as is reasonable under the circumstances given
      the nature of the work) from the time that repair work would commence as
      reasonably determined by Landlord, Tenant may, at its election, terminate
      this Lease by notice given to Landlord within sixty (60) days after the
      date of such fire or other casualty, specifying the effective date of
      termination. The effective date of termination specified by Tenant shall
      be not less than thirty (30) days nor more than forty-five (45) days after
      the date of notice of such termination.

      Unless terminated pursuant to the foregoing provisions, this Lease shall
      remain in full force and effect following any such damage subject,
      however, to the following provisions.

      If the Building or any part thereof is damaged by fire or casualty and
      this Lease is not so terminated, or Landlord or Tenant have no right to
      terminate this Lease, and in any such case the holder of any mortgage
      which includes the Building as a part of the mortgaged premises or any
      ground lessor of any ground lease which includes the Site as part of the
      demised premises allows the net insurance proceeds to be applied to the
      restoration of the Building (and/or the Site), Landlord promptly after
      such damage and the determination of the net amount of insurance proceeds
      available shall use due diligence to restore the Premises and the Building
      in the event of damage thereto (excluding Tenant's Property) into proper
      condition for use and occupation and a just proportion of the Annual Fixed
      Rent, Tenant's share of Operating Costs and Tenant's share of real estate
      taxes according to the nature and extent of the injury to the Premises
      shall be abated until the Premises shall have been put by Landlord
      substantially into such condition except for punch list items and long
      lead items. Notwithstanding anything herein contained to the contrary,
      Landlord shall not be obligated to expend for such repair and restoration
      any amount in excess of the net insurance proceeds.

      Where Landlord is obligated or otherwise elects to effect restoration of
      the Premises, unless such restoration is completed within one (1) year
      from the date of the casualty or taking, such period to be subject,
      however, to extension where the delay in completion of such work is due to
      causes beyond Landlord's reasonable control (but in no event beyond
      eighteen (18) months from the date of the casualty or taking), Tenant
      shall have the right to terminate this Lease at any


                                      -30-
<PAGE>

      time after the expiration of such one-year (as extended) period until the
      restoration is substantially completed, such termination to take effect as
      of the thirtieth (30th) day after the date of receipt by Landlord of
      Tenant's notice, with the same force and effect as if such date were the
      date originally established as the expiration date hereof unless, within
      thirty (30) days after Landlord's receipt of Tenant's notice, such
      restoration is substantially completed, in which case Tenant's notice of
      termination shall be of no force and effect and this Lease and the Lease
      Term shall continue in full force and effect.

6.2   Notwithstanding anything to the contrary contained in this Lease, if the
      Building or the Premises shall be substantially damaged by fire or
      casualty as the result of a risk not covered by the forms of casualty
      insurance at the time maintained by Landlord and such fire or casualty
      damage cannot, in the ordinary course, reasonably be expected to be
      repaired within thirty (30) days from the time that repair work would
      commence, Landlord may, at its election, terminate the Term of this Lease
      by notice to the Tenant given within thirty (30) days after such loss. If
      Landlord shall give such notice, then this Lease shall terminate as of the
      date of such notice with the same force and effect as if such date were
      the date originally established as the expiration date hereof.

6.3   If the entire Building, or such portion of the Premises as to render the
      balance (if reconstructed to the maximum extent practicable in the
      circumstances) unsuitable for Tenant's purposes, shall be taken by
      condemnation or right of eminent domain, Landlord or Tenant shall have the
      right to terminate this Lease by notice to the other of its desire to do
      so, provided that such notice is given not later than thirty (30) days
      after Tenant has been deprived of possession. If either party shall give
      such notice, then this Lease shall terminate as of the date of such notice
      with the same force and effect as if such date were the date originally
      established as the expiration date hereof.

      Further, if so much of the Building or Site shall be so taken that
      continued operation of the Building would be uneconomic as a result of the
      taking, Landlord shall have the right to terminate this Lease by giving
      notice to Tenant of Landlord's desire to do so not later than thirty (30)
      days after Tenant has been deprived of possession of the Premises (or such
      portion thereof as may be taken). If Landlord shall give such notice, then
      this Lease shall terminate as of the date of such notice with the same
      force and effect as if such date were the date originally established as
      the expiration date hereof

      Should any part of the Premises be so taken or condemned during the Lease
      Term hereof, and should this Lease not be terminated in accordance with
      the foregoing provisions, and the holder of any mortgage which includes
      the Premises as part of the mortgaged premises or any ground lessor of any
      ground lease which includes the Site as part of the demised premises
      allows the net condemnation proceeds to


                                      -31-
<PAGE>

      be applied to the restoration of the Building, Landlord agrees that after
      the determination of the net amount of condemnation proceeds available to
      Landlord, Landlord shall use due diligence to put what may remain of the
      Premises into proper condition for use and occupation as nearly like the
      condition of the Premises prior to such taking as shall be practicable
      (excluding Tenant's Property). Notwithstanding the foregoing, Landlord
      shall not be obligated to expend for such repair and restoration any
      amount in excess of the net condemnation proceeds made available to it.

      If the Premises shall be affected by any exercise of the power of eminent
      domain, then the Annual Fixed Rent, Tenant's share of operating costs and
      Tenant's share of real estate taxes shall be justly and equitably abated
      and reduced according to the nature and extent of the loss of use thereof
      suffered by Tenant; and in case of a taking which permanently reduces the
      Rentable Floor Area of the Premises, a just proportion of the Annual Fixed
      Rent, Tenant's share of operating costs and Tenant's share of real estate
      taxes shall be abated for the remainder of the Lease Term.

6.4   Landlord shall have and hereby reserves to itself any and all rights to
      receive awards made for damages to the Premises, the Buildings, the
      Complex and the Site and the leasehold hereby created, or any one or more
      of them, accruing by reason of exercise of eminent domain or by reason of
      anything lawfully done in pursuance of public or other authority. Tenant
      hereby grants, releases and assigns to Landlord all Tenant's rights to
      such awards, and covenants to execute and deliver such further assignments
      and assurances thereof as Landlord may from time to time request, and if
      Tenant shall fail to execute and deliver the same within fifteen (15) days
      after notice from Landlord, Tenant hereby covenants and agrees that
      Landlord shall be irrevocably designated and appointed as its
      attorney-in-fact to execute and deliver in Tenant's name and behalf all
      such further assignments thereof which conform with the provisions hereof.

      Nothing contained herein shall be construed to prevent Tenant from
      prosecuting in any condemnation proceeding a claim for the value of any of
      Tenant's usual trade fixtures installed in the Premises by Tenant at
      Tenant's expense and for relocation and moving expenses, provided that
      such action and any resulting award shall not affect or diminish the
      amount of compensation otherwise recoverable by Landlord from the taking
      authority.

                                   ARTICLE VII

                                     DEFAULT

7.1   (a) If at any time subsequent to the date of this Lease any one or more of
      the following events (herein sometimes called an "Event of Default") shall
      occur:


                                      -32-
<PAGE>

            (i) Tenant shall fail to pay any installment of the Annual Fixed
      Rent, Additional Rent or other charges for which provision is made herein
      on or before the date on which the same become due and payable, and the
      same continues for five (5) business days after notice from Landlord
      thereof, or

            (ii) Landlord having rightfully given the notice specified in
      subdivision (a) above three times in any calendar year, Tenant shall
      thereafter in the same calendar year fail to pay the Annual Fixed Rent,
      Additional Rent or any other monetary amount due under this Lease on or
      before the date on which the same become due and payable, or,

            (iii) Tenant shall neglect or fail to perform or observe any other
      requirement, term, covenant or condition of this Lease (not hereinabove in
      this Section 7.1(a) specifically referred to) on Tenant's part to be
      performed or observed and Tenant shall fail to remedy the same within
      thirty (30) days after notice to Tenant specifying such neglect or
      failure, or if such neglect or failure is of such a nature that Tenant
      cannot reasonably remedy the same within such thirty (30) day period,
      Tenant shall fail to commence promptly to remedy the same and to prosecute
      such remedy to completion with diligence and continuity; or

            (iv) Tenant's leasehold interest in the Premises shall be taken on
      execution or by other process of law directed against Tenant; or

            (v) Tenant shall make an assignment for the benefit of creditors or
      shall file a voluntary petition in bankruptcy or shall be adjudicated
      bankrupt or insolvent, or shall file any petition or answer seeking any
      reorganization, arrangement, composition, readjustment, liquidation,
      dissolution or similar relief for itself under any present or future
      Federal, State or other statute, law or regulation for the relief of
      debtors, or shall seek or consent to or acquiesce in the appointment of
      any trustee, receiver or liquidator of Tenant or of all or any substantial
      part of its properties, or shall admit in writing its inability to pay its
      debts generally as they become due; or

            (vi) A petition shall be filed against Tenant in bankruptcy or under
      any other law seeking any reorganization, arrangement, composition,
      readjustment, liquidation, dissolution, or similar relief under any
      present or future Federal, State or other statute, law or regulation and
      shall remain undismissed or unstayed for an aggregate of sixty (60) days
      (whether or not consecutive), or if any debtor in possession (whether or
      not Tenant) trustee, receiver or liquidator of Tenant or of all or any
      substantial part of its properties or of the Premises shall be appointed
      without the consent or acquiescence of Tenant and such appointment shall
      remain unvacated or unstayed for an aggregate of sixty (60) days (whether
      or not consecutive).


                                      -33-
<PAGE>

      then, and in any of said cases (notwithstanding any license of a former
      breach of covenant or waiver of the benefit hereof or consent in a former
      instance), Landlord lawfully may, immediately or at any time thereafter,
      and without demand or further notice terminate this Lease by notice to
      Tenant, specifying a date not less than five (5) days after the giving of
      such notice on which this Lease shall terminate, and this Lease shall come
      to an end on the date specified therein as fully and completely as if such
      date were the date herein originally fixed for the expiration of the Lease
      Term (Tenant hereby waiving any rights of redemption), and Tenant will
      then quit and surrender the Premises to Landlord, but Tenant shall remain
      liable as hereinafter provided.

      (b) If this Lease shall have been terminated as provided in this Article,
      then Landlord may, without notice, re-enter the Premises, either by force,
      summary proceedings, ejectment or otherwise, and remove and dispossess
      Tenant and all other persons and any and all property from the same, as if
      this Lease had not been made, and Tenant hereby waives the service of
      notice of intention to re-enter or to institute legal proceedings to that
      end.

      (c) In the event that this Lease is terminated under any of the provisions
      contained in Section 7.1 (a) or shall be otherwise terminated by breach of
      any obligation of Tenant, Tenant covenants and agrees forthwith to pay and
      be liable for, on the days originally fixed herein for the payment
      thereof, amounts equal to the several installments of rent and other
      charges reserved as they would, under the terms of this Lease, become due
      if this Lease had not been terminated or if Landlord had not entered or
      re-entered, as aforesaid, and whether the Premises be relet or remain
      vacant, in whole or in part, or for a period less than the remainder of
      the Term, and for the whole thereof, but in the event the Premises be
      relet by Landlord, Tenant shall be entitled to a credit in the net amount
      of rent and other charges received by Landlord in reletting, after
      deduction of all expenses incurred in reletting the Premises (including,
      without limitation, remodeling costs, brokerage fees and the like), and in
      collecting the rent in connection therewith, in the following manner:

      Amounts received by Landlord after reletting shall first be applied
      against such Landlord's expenses, until the same are recovered, and until
      such recovery, Tenant shall pay, as of each day when a payment would fall
      due under this Lease, the amount which Tenant is obligated to pay under
      the terms of this Lease (Tenant's liability prior to any such reletting
      and such recovery not in any way to be diminished as a result of the fact
      that such reletting might be for a rent higher than the rent provided for
      in this Lease); when and if such expenses have been completely recovered,
      the amounts received from reletting by Landlord as have not previously
      been applied shall be credited against Tenant's obligations as of


                                      -34-
<PAGE>

      each day when a payment would fall due under this Lease, and only the net
      amount thereof shall be payable by Tenant. Further, amounts received by
      Landlord from such reletting for any period shall be credited only against
      obligations of Tenant allocable to such period, and shall not be credited
      against obligations of Tenant hereunder accruing subsequent or prior to
      such period; nor shall any credit of any kind be due for any period after
      the date when the term of this Lease is scheduled to expire according to
      its terms.

      (d)   (i) Landlord may elect, as an alternative, to have Tenant pay
            liquidated damages, which election may be made by notice given to
            Tenant at any time after the termination of this Lease under Section
            7.2, above, and whether or not Landlord shall have collected any
            damages as hereinbefore provided in this Article VII, and in lieu of
            all other such damages beyond the date of such notice. Upon such
            notice, Tenant shall promptly pay to Landlord, as liquidated
            damages, in addition to any damages collected or due from Tenant
            from any period prior to such notice and all expenses which Landlord
            may have incurred with respect to the collection of such damages,
            such a sum as at the time of such notice represents the amount of
            the excess, if any, of (a) the discounted present value, at a
            discount rate of 6%, of the Annual Fixed Rent, Additional Rent and
            other charges which would have been payable by Tenant under this
            Lease for the remainder of the Lease Term if the Lease terms had
            been fully complied with by Tenant, over and above (b) the
            discounted present value, at a discount rate of 6%, of the Annual
            Fixed Rent, Additional Rent and other charges that would be received
            by Landlord if the Premises were re- leased at the time of such
            notice for the remainder of the Lease Term at the fair market value
            (including provisions regarding periodic increases in Annual Fixed
            Rent if such are applicable) prevailing at the time of such notice
            as reasonably determined by Landlord.

            (ii) For the purposes of this Article, if Landlord elects to require
            Tenant to pay damages in accordance with the immediately preceding
            paragraph, the total rent shall be computed by assuming that
            Tenant's share of excess taxes, Tenant's share of excess operating
            costs and Tenant's share of excess electrical costs would be, for
            the balance of the unexpired Term from the date of such notice, the
            amount thereof (if any) for the immediately preceding annual period
            payable by Tenant to Landlord.

      (e) In case of any Event of Default, re-entry, dispossession by summary
      proceedings or otherwise, Landlord may (i) re-let the Premises or any part
      or parts thereof, either in the name of Landlord or otherwise, 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
      of this Lease and may


                                      -35-
<PAGE>

      grant concessions or free rent to the extent that Landlord considers
      advisable or necessary to re-let the same and (ii) may make such
      alterations, repairs and decorations in the Premises as Landlord in its
      sole judgment considers advisable or necessary for the purpose of
      reletting the Premises; and the making of such alterations, repairs and
      decorations shall not operate or be construed to release Tenant from
      liability hereunder as aforesaid. Landlord shall in no event be liable in
      any way whatsoever for failure to re-let the Premises, or, in the event
      that the Premises are re-let, for failure to collect the rent under
      re-letting. Tenant, for itself and any and all persons claiming through or
      under Tenant, including its creditors, upon the termination of this Lease
      and of the term of this Lease in accordance with the terms hereof, or in
      the event of entry of judgment for the recovery of the possession of the
      Premises in any action or proceeding, or if Landlord shall enter the
      Premises by process of law or otherwise, hereby waives any right of
      redemption provided or permitted by any statute, law or decision now or
      hereafter in force, and does hereby waive, surrender and give up all
      rights or privileges which it or they may or might have under and by
      reason of any present or future law or decision, to redeem the Premises or
      for a continuation of this Lease for the term of this Lease hereby demised
      after having been dispossessed or ejected therefrom by process of law, or
      otherwise.

      (f) The specified remedies to which Landlord may resort hereunder are not
      intended to be exclusive of any remedies or means of redress to which
      Landlord may at any time be entitled lawfully, and Landlord may invoke any
      remedy (including the remedy of specific performance) allowed at law or in
      equity as if specific remedies were not herein provided for. Further,
      nothing contained in this Lease shall limit or prejudice the right of
      Landlord to prove for and obtain in proceedings for bankruptcy or
      insolvency 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.

7.2   Landlord shall in no event be in default in the performance of any of
      Landlord's obligations hereunder unless and until Landlord shall have
      failed to perform such obligations within thirty (30) days, or such
      additional time as is reasonably required to correct any such default,
      after notice by Tenant to Landlord properly specifying wherein Landlord
      has failed to perform any such obligation.

                                  ARTICLE VIII

                                  MISCELLANEOUS

8.1   Tenant covenants and agrees that Tenant will not do or permit anything to
      be done in or upon the Premises, or bring in anything or keep anything
      therein, which shall


                                      -36-
<PAGE>

      increase the rate of insurance on the Premises or on the Building above
      the standard rate applicable to premises being occupied for the use to
      which Tenant has agreed to devote the Premises; and Tenant further agrees
      that, in the event that Tenant shall do any of the foregoing, Tenant will
      promptly pay to Landlord, on demand, any such increase resulting
      therefrom, which shall be due and payable as additional rent thereunder.

8.2   Failure on the part of Landlord or Tenant to complain of any action or
      non-action on the part of the other, no matter how long the same may
      continue, shall never be a waiver by Tenant or Landlord, respectively, of
      any of its rights hereunder. Further, no waiver at any time of any of the
      provisions hereof by Landlord or Tenant shall be construed as a waiver of
      any of the other provisions hereof, and a waiver at any time of any of the
      provisions hereof shall not be construed as a waiver at any subsequent
      time of the same provisions. The consent or approval of Landlord or Tenant
      to or of any action by the other requiring such consent or approval shall
      not be construed to waive or render unnecessary Landlord's or Tenant's
      consent or approval to or of subsequent similar act by the other. Further,
      the acceptance by Landlord of Annual Fixed Rent, Additional Rent or any
      other charges paid by Tenant under this Lease shall not be or be deemed to
      be a waiver by Landlord of any default by Tenant, whether or not Landlord
      knows of such default, except for such defaults as to which such payment
      relates.

      No payment by Tenant, or acceptance by Landlord, of a lesser amount than
      shall be due from Tenant to Landlord shall be treated otherwise than as a
      payment on account. The acceptance by Landlord of a check for a lesser
      amount with an endorsement or statement thereon, or upon any letter
      accompanying such check, that such lesser amount is payment in full, shall
      be given no effect, and Landlord may accept such check without prejudice
      to any other rights or remedies which Landlord may have against Tenant.

8.3   The specific remedies to which Landlord may resort under the terms of this
      Lease are cumulative and are not intended to be exclusive of any other
      remedies or means of redress to which such party may be lawfully entitled
      in case of any breach or threatened breach by Tenant of any provisions of
      this Lease. In addition to the other remedies provided in this Lease,
      Landlord shall be entitled to the restraint by injunction of the violation
      or attempted or threatened violation of any of the covenants, conditions
      or provisions of this Lease or to a decree compelling specific performance
      of any such covenants, conditions or provisions.

8.4   Tenant, subject to the terms and provisions of this Lease on payment of
      the rent and observing, keeping and performing all of the terms and
      provisions of this Lease on Tenant's part to be observed, kept and
      performed, shall lawfully, peaceably and quietly have, hold, occupy and
      enjoy the Premises during the Term, without hindrance or ejection by any
      persons lawfully claiming under Landlord to


                                      -37-
<PAGE>

      have title to the Premises superior to Tenant, subject, however, to the
      terms of this Lease; the foregoing covenant of quiet enjoyment is in lieu
      of any other covenant, express or implied; and it is understood and agreed
      that this covenant and any and all other covenants of Landlord contained
      in this Lease shall be binding upon Landlord and Landlord's successors
      only with respect to breaches occurring during Landlord's or Landlord's
      successors' respective ownership of Landlord's interest hereunder,
      including ground or master lessees, to the extent of their respective
      interests, as and when they shall acquire same and then only for so long
      as they shall retain such interest.

      Further, Tenant specifically agrees to look solely to Landlord's then
      equity interest in the Building at the time owned, or in which Landlord
      holds an interest as ground lessee, for recovery of any judgment from
      Landlord; it being specifically agreed that neither Landlord (original or
      successor), nor any beneficiary of any Trust of which any person holding
      Landlord's interest is Trustee, nor any member, manager, partner, director
      or stockholder nor Landlord's managing agent shall ever be personally
      liable for any such judgment, or for the payment of any monetary
      obligation to Tenant. The provision contained in the foregoing sentence is
      not intended to, and shall not, limit any right that Tenant might
      otherwise have to obtain injunctive relief against Landlord or Landlord's
      successors in interest, or any action not involving the personal liability
      of Landlord (original or successor), any successor Trustee to the persons
      named herein as Landlord, or any beneficiary of any Trust of which any
      person holding Landlord's interest is Trustee, or of any manager, member,
      partner, director or stockholder of Landlord or of Landlord's managing
      agent, to respond in monetary damages from Landlord's assets other than
      Landlord's equity interest aforesaid in the Building. In no event shall
      Landlord ever be liable to Tenant for any indirect or consequential
      damages or lost profits suffered by Tenant from whatever cause or loss of
      profits or the like. In the event that Landlord shall be determined to
      have acted unreasonably in withholding any consent or approval under this
      Lease, the sole recourse and remedy of the Tenant in respect thereof shall
      be to specifically enforce Landlord's obligation to grant such consent or
      approval, and in no event shall the Landlord be responsible for any
      damages of whatever nature in respect of its failure to give such consent
      or approval nor shall the same otherwise affect the obligations of the
      Tenant under this Lease or act as any termination of this Lease.

8.5   After receiving notice from any person, firm or other entity that it holds
      a mortgage which includes the Premises as part of the mortgaged premises,
      or that it is the ground lessor under a lease with Landlord, as ground
      lessee, which includes the Premises as a part of the mortgaged premises,
      no notice from Tenant to Landlord shall be effective unless and until a
      copy of the same is given to such holder or ground lessor, and the curing
      of any of Landlord's defaults by such holder or ground lessor within a
      reasonable time thereafter (including a reasonable


                                      -38-
<PAGE>

      time to obtain possession of the premises if the mortgagee or ground
      lessor elects to do so) shall be treated as performance by Landlord. For
      the purposes of this Section 8.5 or Section 8.15, the term "mortgage"
      includes a mortgage on a leasehold interest of Landlord (but not one on
      Tenant's leasehold interest). If any mortgage is listed on Exhibit G then
      the same shall constitute notice from the holder of such mortgage for the
      purposes of this Section 8.5. Further no Annual Fixed Rent or Additional
      Rent may be paid by Tenant more than thirty (30) days in advance except
      with the prior written consent of all holder(s) of such mortgages and
      ground leases, and any such payment without such consent shall not be
      binding on such holder(s).

8.6   With reference to any assignment by Landlord of Landlord's interest in
      this Lease, or the rents payable hereunder, conditional in nature or
      otherwise, which assignment is made to the holder of a mortgage or ground
      lease on property which includes the Premises, Tenant agrees:

      (a) That the execution thereof by Landlord, and the acceptance thereof by
      the holder of such mortgage or the ground lessor, shall never be treated
      as an assumption by such holder or ground lessor of any of the obligations
      of Landlord hereunder, unless such holder, or ground lessor, shall, by
      notice sent to Tenant, specifically otherwise elect; and

      (b) That, except as aforesaid, such holder or ground lessor shall be
      treated as having assumed Landlord's obligations hereunder only upon
      foreclosure of such holder's mortgage and the taking of possession of the
      Premises, or, in the case of a ground lessor, the assumption of Landlord's
      position hereunder by such ground lessor.

      In no event shall the acquisition of title to the Building and the land on
      which the same is located by a purchaser which, simultaneously therewith,
      leases the entire Building or such land back to the seller thereof be
      treated as an assumption by such purchaser-lessor, by operation of law or
      otherwise, of Landlord's obligations hereunder, but Tenant shall look
      solely to such seller-lessee, and its successors from time to time in
      title, for performance of Landlord's obligations hereunder subject to the
      provisions of Section 8.4 hereof. In any such event, this Lease shall be
      subject and subordinate to the lease to such purchaser provided that such
      purchaser agrees to recognize the right of Tenant to use and occupy the
      Premises upon the payment of rent and other charges payable by Tenant
      under this Lease and the performance by Tenant of Tenant's obligations
      hereunder and provided that Tenant agrees to attorn to such purchaser. For
      all purposes, such seller-lessee, and its successors in title, shall be
      the landlord hereunder unless and until Landlord's position shall have
      been assumed by such purchaser-lessor.


                                      -39-
<PAGE>

8.7   (A) No act or thing done by Landlord during the Lease Term shall be deemed
      an acceptance of a surrender of the Premises, and no agreement to accept
      such surrender shall be valid, unless in writing signed by Landlord. No
      employee of Landlord or of Landlord's agents shall have any power to
      accept the keys of the Premises prior to the termination of this Lease,
      provided, however, that the foregoing shall not apply to the delivery of
      keys to Landlord or its agents in its (or their) capacity as managing
      agent or for purpose of emergency access. In any event, however, the
      delivery of keys to any employee of Landlord or of Landlord's agents shall
      not operate as a termination of the Lease or a surrender of the Premises.

      (B) Upon the expiration or earlier termination of the Lease Term, Tenant
      shall surrender the Premises to Landlord in the condition as required by
      Sections 3.3 and 5.2, first removing all goods and effects of Tenant and
      completing such other removals as may be permitted or required pursuant to
      Section 5.2.

8.8   (A) Tenant warrants and represents that Tenant has not dealt with any
      broker in connection with the consummation of this Lease other than the
      broker, person or firm, if any, designated in Section 1.1 hereof; and in
      the event any claim is made against the Landlord relative to dealings by
      Tenant with brokers other than the Brokers, if any, designated in Section
      1.1 hereof, Tenant shall defend the claim against Landlord with counsel of
      Tenant's selection first approved by Landlord (which approval will not be
      unreasonably withheld) and save harmless and indemnify Landlord on account
      of loss, cost or damage which may arise by reason of such claim.

      (B) Landlord warrants and represents that Landlord has not dealt with any
      broker in connection with the consummation of this Lease other than the
      broker, person or firm, if any, designated in Section 1.1 hereof; and in
      the event any claim is made against the Tenant relative to dealings by
      Landlord with brokers other than the Brokers, if any, designated in
      Section 1.1 hereof, Landlord shall defend the claim against Tenant with
      counsel of Landlord's selection and save harmless and indemnify Tenant on
      account of loss, cost or damage which may arise by reason of such claim.
      Landlord agrees that it shall be solely responsible for the payment of
      brokerage commissions to the Broker, if any, designated in Section 1.1
      hereof.

8.9   If any term or provision of this Lease, or the application thereof to any
      person or circumstance shall, to any extent, be invalid or unenforceable,
      the remainder of this Lease, or the application of such term or provision
      to persons or circumstances other than those as to which it is held
      invalid or unenforceable, shall not be affected thereby, and each term and
      provision of this Lease shall be valid and be enforced to the fullest
      extent permitted by law.


                                      -40-
<PAGE>

8.10  The obligations of this Lease shall run with the land, and except as
      herein otherwise provided, the terms hereof shall be binding upon and
      shall inure to the benefit of the successors and assigns, respectively, of
      Landlord and Tenant and, if Tenant shall be an individual, upon and to his
      heirs, executors, administrators, successors and assigns. Each term and
      each provision of this Lease to be performed by Tenant shall be construed
      to be both a covenant and a condition. The reference contained to
      successors and assigns of Tenant is not intended to constitute a consent
      to subletting or assignment by Tenant, but has reference only to those
      instances in which Landlord may have later given consent to a particular
      assignment as required by the provisions of Article V hereof.

8.11  Tenant agrees not to record the within Lease, but each party hereto
      agrees, on the request of the other, to execute a so-called Notice of
      Lease or short form lease in form recordable and complying with applicable
      law and reasonably satisfactory to both Landlord's and Tenant's attorneys.
      In no event shall such document set forth rent or other charges payable by
      Tenant under this Lease; and any such document shall expressly state that
      it is executed pursuant to the provisions contained in this Lease, and is
      not intended to vary the terms and conditions of this Lease.

8.12  Whenever, by the terms of this Lease, notice shall or may be given either
      to Landlord or to Tenant, such notice shall be in writing and shall be
      sent by registered or certified mail postage prepaid:

      If intended for Landlord, addressed to Landlord at the address set forth
      on the first page of this Lease (or to such other address or addresses as
      may from time to time hereafter be designated by Landlord by like notice)
      with a copy to Landlord, Attention: General Counsel.

      If intended for Tenant, addressed to Tenant at the address set forth on
      the second page of this Lease except that from and after the Commencement
      Date the address of Tenant shall be the Premises (or to such other address
      or addresses as may from time to time hereafter be designated by Tenant by
      like notice).

      Except as otherwise provided herein, all such notices shall be effective
      when received; provided, that (i) if receipt is refused, notice shall be
      effective upon the first occasion that such receipt is refused or (ii) if
      the notice is unable to be delivered due to a change of address of which
      no notice was given, notice shall be effective upon the date such delivery
      was attempted.

      Where provision is made for the attention of an individual or department,
      the notice shall be effective only if the wrapper in which such notice is
      sent is addressed to the attention of such individual or department.


                                      -41-
<PAGE>

      Any notice given by an attorney on behalf of Landlord or by Landlord's
      managing agent shall be considered as given by Landlord and shall be fully
      effective.

      Time is of the essence with respect to any and all notices and periods for
      giving notice or taking any action thereto under this Lease.

8.13  Employees or agents of Landlord have no authority to make or agree to make
      a lease or any other agreement or undertaking in connection herewith. The
      submission of this document for examination and negotiation does not
      constitute an offer to lease, or a reservation of, or option for, the
      Premises, and this document shall become effective and binding only upon
      the execution and delivery hereof by both Landlord and Tenant. All
      negotiations, considerations, representations and understandings between
      Landlord and Tenant are incorporated herein and may be modified or altered
      only by written agreement between Landlord and Tenant, and no act or
      omission of any employee or agent of Landlord shall alter, change or
      modify any of the provisions hereof.

8.14  The titles of the Articles throughout this Lease are for convenience and
      reference only, and the words contained therein shall in no way be held to
      explain, modify, amplify or aid in the interpretation, construction or
      meaning of the provisions of this Lease.

8.15  This Lease shall be subject and subordinate to any mortgage now or
      hereafter on the Site or the Building, or both, and to each advance made
      or hereafter to be made under any mortgage, and to all renewals,
      modifications, consolidations, replacements and extensions thereof and all
      substitutions therefor provided that in the case of a future mortgage the
      holder of such mortgage agrees to recognize the rights of Tenant under
      this Lease (including the right to use and occupy the Premises) upon the
      payment of rent and other charges payable by Tenant under this Lease and
      the performance by Tenant of Tenant's obligations hereunder. In
      confirmation of such subordination and recognition, Tenant shall execute
      and deliver promptly such instruments of subordination and recognition as
      such mortgagee may reasonably request. Tenant hereby appoints such
      mortgagee (from time to time) as Tenant's attorney-in-fact to execute such
      subordination upon default of Tenant in complying with such mortgagee's
      (from time to time) request. In the event that any mortgagee or its
      respective successor in title shall succeed to the interest of Landlord,
      then, this Lease shall nevertheless continue in full force and effect and
      Tenant shall and does hereby agree to attorn to such mortgagee or
      successor and to recognize such mortgagee or successor as its landlord. If
      any holder of a mortgage which includes the Premises, executed and
      recorded prior to the date of this Lease, shall so elect, this Lease and
      the rights of Tenant hereunder, shall be superior in right to the rights
      of such holder, with the same force and effect as if this Lease had been
      executed, delivered and recorded, or a statutory Notice hereof recorded,
      prior to the execution, delivery and


                                      -42-
<PAGE>

      recording of any such mortgage. The election of any such holder shall
      become effective upon either notice from such holder to Tenant in the same
      fashion as notices from Landlord to Tenant are to be given hereunder or by
      the recording in the appropriate registry or recorder's office of an
      instrument in which such holder subordinates its rights under such
      mortgage to this Lease.

      If in connection with obtaining financing for the Building or Complex, a
      bank, insurance company, pension trust or other institutional lender shall
      request reasonable modifications in this Lease as a condition to such
      financing, Tenant will not unreasonably withhold, delay or condition its
      consent thereto, provided that such modifications do not increase the
      monetary obligations of Tenant hereunder or materially adversely affect
      the leasehold interest hereby created.

8.16  Recognizing that Landlord may find it necessary to establish to third
      parties, such as accountants, banks, potential or existing mortgagees,
      potential purchasers or the like, the then current status of performance
      hereunder, Tenant, within ten (10) days after the request of Landlord made
      from time to time, will furnish to Landlord, or any existing or potential
      holder of any mortgage encumbering the Premises, the Building, the Site
      and/or the Complex or any potential purchaser of the Premises, the
      Building, the Site and/or the Complex, (each an "Interested Party"), a
      statement of the status of any matter pertaining to this Lease, including,
      without limitation, acknowledgments that (or the extent to which) each
      party is in compliance with its obligations under the terms of this Lease.
      In addition, Tenant shall deliver to Landlord, or any Interested Party
      designated by Landlord, financial statements of Tenant and any guarantor
      of Tenant's obligations under this Lease, as reasonably requested by
      Landlord, including, but not limited to financial statements for the past
      three (3) years. Any such status statement or financial statement
      delivered by Tenant pursuant to this Section 8.16 may be relied upon by
      any Interested Party.

8.17  If Tenant shall at any time default in the performance of any obligation
      under this Lease, Landlord shall have the right, but shall not be
      obligated, to enter upon the Premises and to perform such obligation
      notwithstanding the fact that no specific provision for such substituted
      performance by Landlord is made in this Lease with respect to such
      default. In performing such obligation, Landlord may make any payment of
      money or perform any other act. All sums so paid by Landlord (together
      with interest at the rate of two and one-half percentage points over the
      then prevailing prime or base rate in Boston as set by BankBoston, N.A.,
      or its successor) (but in no event greater than the maximum rate permitted
      by applicable law) and all costs and expenses in connection with the
      performance of any such act by Landlord, shall be deemed to be additional
      rent under this Lease and shall be payable to Landlord immediately on
      demand. Landlord may exercise the foregoing rights without waiving any
      other of its rights or releasing Tenant from any of its obligations under
      this Lease.


                                      -43-
<PAGE>

8.18  Any holding over by Tenant after the expiration of the term of this Lease
      shall be treated as a tenancy at sufferance and shall be on the terms and
      conditions as set forth in this Lease, as far as applicable except that
      Tenant shall pay as a use and occupancy charge an amount equal to the
      greater of (x) 200% of the Annual Fixed Rent and Additional Rent
      calculated (on a daily basis) at the highest rate payable under the terms
      of this Lease or (y) the fair market rental value of the Premises, in each
      case for the period measured from the day on which Tenant's hold-over
      commences and terminating on the day on which Tenant vacates the Premises.
      In addition, Tenant shall save Landlord, its agents and employees harmless
      and will exonerate, defend and indemnify Landlord, its agents and
      employees from and against any and all damages which Landlord may suffer
      on account of Tenant's hold-over in the Premises after the expiration or
      prior termination of the term of this Lease. Nothing in the foregoing nor
      any other term or provision of this Lease shall be deemed to permit Tenant
      to retain possession of the Premises or hold over in the Premises after
      the expiration or earlier termination of the Lease Term. All property
      which remains in the Building or the Premises after the expiration or
      termination of this Lease shall be conclusively deemed to be abandoned and
      may either be retained by Landlord as its property or sold or otherwise
      disposed of in such manner as Landlord may see fit. If any part thereof
      shall be sold, then Landlord may receive the proceeds of such sale and
      apply the same, at its option against the expenses of the sale, the cost
      of moving and storage, any arrears of rent or other charges payable
      hereunder by Tenant to Landlord and any damages to which Landlord may be
      entitled under this Lease and at law and in equity.

8.19  Any insurance carried by either party with respect to the Premises or
      property therein or occurrences thereon shall, if it can be so written
      without additional premium or with an additional premium which the other
      party agrees to pay, include a clause or endorsement denying to the
      insurer rights of subrogation against the other party to the extent rights
      have been waived by the insured prior to occurrence of injury or loss.
      Each party, notwithstanding any provisions of this Lease to the contrary,
      hereby waives any rights of recovery against the other for injury or loss
      due to hazards covered by such insurance to the extent of the
      indemnification received thereunder. This waiver of rights by Tenant shall
      apply to, and be for the benefit of, Landlord's managing agent.

8.20  Intentionally Omitted.

8.21  If; in Section 1.1 hereof, a security deposit is specified, Tenant agrees
      that the same will be paid upon execution and delivery of this Lease, and
      that Landlord shall hold the same, throughout the term of this Lease
      (including any extension thereof), as security for the performance by
      Tenant of all obligations on the part of Tenant to be kept and performed.
      Landlord shall have the right from time to time without prejudice to any
      other remedy Landlord may have on account thereof, to


                                      -44-
<PAGE>

      apply such deposit, or any part thereof; to Landlord's damages arising
      from any default on the part of Tenant. If Landlord so applies all or any
      portion of such deposit, Tenant shall within seven (7) days after notice
      from Landlord deliver cash to Landlord in an amount sufficient to restore
      such deposit to the full amount stated in Section 1.1. Tenant not then
      being in default and having performed all of its obligations under this
      Lease, including the payment of all Annual Fixed Rent, Landlord shall
      return the deposit, or so much thereof as shall not have theretofore been
      applied in accordance with the terms of this Section 8.21, to Tenant on
      the expiration or earlier termination of the term of this Lease and
      surrender possession of the Premises by Tenant to Landlord in the
      condition required in the Lease at such time. While Landlord holds such
      deposit, Landlord shall have no obligation to pay interest on the same and
      shall have the right to commingle the same with Landlord's other funds. If
      Landlord conveys Landlord's interest under this Lease, the deposit, or any
      part thereof not previously applied, may be turned over by Landlord to
      Landlord's grantee, and, if so turned over, Tenant agrees to look solely
      to such grantee for proper application of the deposit in accordance with
      the terms of this Section 8.21, and the return thereof in accordance
      herewith, and Landlord shall have no further liability therefor.

      Neither the holder of any mortgage nor the lessor in any ground lease on
      property which includes the Premises shall ever be responsible to Tenant
      for the return or application of any such deposit, whether or not it
      succeeds to the position of Landlord hereunder, unless such deposit shall
      have been received in hand by such holder or ground lessor.

8.22  If Landlord shall not have received any payment or installment of Annual
      Fixed Rent or Additional Rent on or before the date (the "Due Date") on
      which the same first becomes payable under this Lease, the amount of such
      payment or installment shall bear interest from the Due Date through and
      including the date such payment or installment is received by Landlord, at
      a rate equal to the lesser of (i) the rate announced by BankBoston, N.A.
      or its successor from time to time as its prime or base rate (or if such
      rate is no longer available, a comparable rate reasonably selected by
      Landlord), plus two percent (2%), or (ii) the maximum applicable legal
      rate, if any. Such interest shall be deemed additional rent and shall be
      paid by Tenant to Landlord upon demand.

8.23  This Lease shall be governed exclusively by the provisions hereof and by
      the law of the Commonwealth of Massachusetts, as the same may from time to
      time exist.

8.24  Each and every payment and expenditure, other than Annual Fixed Rent,
      shall be deemed to be Additional Rent hereunder, whether or not the
      provisions requiring payment of such amounts specifically so state, and
      shall be payable, unless otherwise provided in this Lease, within ten (10)
      days after written demand by


                                      -45-
<PAGE>

      Landlord, and in the case of the non-payment of any such amount, Landlord
      shall have, in addition to all of its other rights and remedies, all the
      rights and remedies available to Landlord hereunder or by law in the case
      of non-payment of Annual Fixed Rent. Unless expressly otherwise provided
      in this Lease, the performance and observance by Tenant of all the terms,
      covenants and conditions of this Lease to be performed and observed by
      Tenant shall be at Tenant's sole cost and expense. If Tenant has not
      objected to any statement of Additional Rent which is rendered by Landlord
      to Tenant within ninety (90) days after Landlord has rendered the same to
      Tenant, then the same shall be deemed to be a final account between
      Landlord and Tenant not subject to any further dispute. In the event that
      Tenant shall seek Landlord's consent or approval under this Lease, then
      Tenant shall reimburse Landlord, upon demand, as Additional Rent, for all
      reasonable costs and expenses, including legal and architectural costs and
      expenses, incurred by Landlord in processing such request, whether or not
      such consent or approval shall be given.


                                      -46-
<PAGE>

      EXECUTED as a sealed instrument in two or more counterparts each of which
shall be deemed to be an original.


WITNESS:                            LANDLORD:
                                    BOSTON PROPERTIES LIMITED
                                    PARTNERSHIP
                                    By BOSTON PROPERTIES, INC.,
                                         Its general partner


/s/ S. J. Murphy                    By    /s/ Claude B. Hooper
---------------------------               -----------------------------
                                    Name  CLAUDE B. HOOPER
                                          -----------------------------
                                    Title Vice President
                                          -----------------------------


                                    TENANT:
                                    ADVANCED LUMITECH, INC.


                                    By    /s/ Patrick Planche
                                          -----------------------------
                                    Name  PATRICK PLANCHE
                                          -----------------------------
                                    Title PRESIDENT
                                          -----------------------------
                                          (OR VICE PRESIDENT)
                                          -----------------------------
                                          HERETO DULY AUTHORIZED


ATTEST:


/s/ Patrick Planche
---------------------------
Name PATRICK PLANCHE                By    /s/ Patrick Planche
     ----------------------               -----------------------------
Title SECRETARY                     Name  PATRICK PLANCHE
     ----------------------               -----------------------------
    (ASSISTANT SECRETARY)           Title TREASURER
                                          -----------------------------
                                          (OR ASSISTANT TREASURER)
                                          -----------------------------
                                          HERETO DULY AUTHORIZED

(CORPORATE SEAL)                          /s/ Alan M. Cregg
                                          -----------------------------
                                    Name  Alan M. Cregg
                                          -----------------------------
                                    Title Attorney for Advanced Lumitech, Inc.
                                          -----------------------------


                                      -47-
<PAGE>

                                    EXHIBIT A

                                   Description

      A parcel of land (the "Land") in Waltham and Lexington, Middlesex County,
Massachusetts containing 34.372 acres and shown on that certain plan entitled
"Plan of Land in Waltham and Lexington, Middlesex Co., Mass.", dated March
6,1986, prepared by Land Surveys Incorporated, recorded with the Middlesex South
District Registry of Deeds (the "Registry") in Book 17090, Page End (the
"Plan"), bounded and described as follows:

EASTERLY                by the Northern Circumferential Highway (Route 128) by
                        two lines measuring 1,067.16 feet and 127.72 feet;

SOUTHEASTERLY
AND SOUTHERLY           by the ramp to Trapelo Road and Trapelo Road by five
                        lines measuring 309.05 feet, 262.57 feet, 122.01 feet,
                        78.18 feet, and 8.38 feet;

NORTHWESTERLY           by land N/F Reservoir Place Realty Trust, 110 feet;

SOUTHERLY               by land N/F Reservoir Place Realty Trust, 96.07 feet,
                        and by land N/F William and Louise Butler, 99 feet;

NORTHWESTERLY           by land N/F Thomas P. and Sandra H. Kehoe, 105 feet;

SOUTHERLY               62 feet,

SOUTHEASTERLY           39.27 feet and 160 feet, and

NORTH-EASTERLY          39.27 feet, all by land of N/F Thomas P, and Sandra H.
                        Kehoe;

SOUTHWESTERLY           by Trapelo Road, 95 feet;

NORTHWESTERLY           39.27 feet and 100 feet, and

SOUTHWESTERLY           102.57 feet, all by land N/F Leonard and Evalyn Weld;

NORTHWESTERLY           275 feet, and

SOUTHWESTERLY           122.35, by land N/F Robert L. and Barbara T. Anderson;


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NORTHWESTERLY           by two lines measuring 235.15 feet and 284.27 feet, by
                        lands N/F Edward J. and Beverly J. Mirabito, Carol Lane,
                        N/F Charles J. Senior, Jr., N/F Donald and Shirley
                        Gibbs, N/F Raymond R. and Bridget Picard, and N/F Henry
                        F. Miller;

WESTERLY                by five lines measuring 580.06 feet, 25 feet, 128.21
                        feet, 344.66 feet and 9.12 feet, by lands N/F Henry P,
                        Miller, N/F John H. and Nancy Russell, N/F Frederick and
                        Anne Creamer, N/F J.S.C. Realty Trust, N/F Santo and
                        Catherine Lafauci, N/F Jean Yves and Annette Morn, N/F
                        Helen K. Hickey, Priscilla Lane, N/F Stanley C. and
                        Louise H. Whynock, and the City of Waltham;

NORTHEASTERLY           692.16 feet by land N/F The C-R Trust;

EASTERLY                137.39 feet by Route 128;

SOUTHWESTERLY           by two lines measuring 336.67 feet and 286.94 feet by
                        land N/F Tracer Lane Trust;

EASTERLY                by two lines measuring 506.14 feet and 325.94 feet, by
                        land N/F Tracer Lane Trust;

NORTHERLY               45 feet,

WESTERLY                27 feet, and

NORTHERLY               555.01 feet, all by land N/F Tracer Lane Trust.

      Together with the right, in common with others, to use Tracer Lane, a
private way, throughout its entire length over the Land, for access to and from
Trapelo Road, a public way, and for all other purposes for which public ways are
normally used in the City of Waltham and the Town of Lexington, as shown on the
Plan.

      Together with the appurtenant right in common with others to use that
portion of the Land located within the easement granted to Boston Edison Company
by a Grant of Easement dated October 2, 1946 and recorded in the Registry in
Book 7098, Page 118, for all purposes allowed under an Agreement with Boston
Edison Company and Albamont Properties, Inc. dated January 31, 1975 and recorded
in the Registry in Book 12771, Page 538.


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      Together with the appurtenant right and easement, in common with others,
to discharge surface water contained in an Easement Indenture among Tracerlab,
Inc. et al. dated January 9, 1957 and recorded in the Registry in Book 8892,
Page 112.

      Together with the appurtenant rights and easements, in common with others,
granted to the owner of the Land in (a) an Indenture among Boston Edison Company
et al. Dated September 19, 1966 and recorded in the Registry in Book 11258, Page
79, (b) a Utilities Maintenance Agreement among LFE Inc. et al dated September
19, 1966 and recorded in the Registry in Book 11258, Page 92, and (c) an
Easement Indenture among 128 Realty Corporation et al. dated September 19, 1966
and recorded in the Registry in Book 11258, Page 061.

      Together with the right and easement, in common with others, granted the
owner of the Land in an Agreement dated May 12,1975 and recorded in the Registry
in Book 12892, Page 410.

Together with the right to terminate the Agreement between Leonard N. Weld et
ux. dated April 9,1974 and recorded in the Registry in Book 12627, Page 235.


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                                    EXHIBIT B

                       TENANT PLAN AND WORKING DRAWING REQUIREMENTS


1. Floor plan indicating location of partitions and doors (details required of
partition and door types).

2. Location of standard electrical convenience outlets and telephone outlets.

3. Location and details of special electrical outlets; (e.g. Xerox), including
voltage, amperage, phase and NEMA configuration of outlets.

4. Reflected ceiling plan showing layout of standard ceiling and lighting
fixtures. Partitions to be shown lightly with switches located indicating
fixtures to be controlled.

5. Locations and details of special ceiling conditions, lighting fixtures,
speakers, etc.

6. Location and heat load in BTU/Hr. of all special air conditioning and
ventilating requirements and all necessary HVAC mechanical drawings.

7. Location and details of special structural requirements, e.g., slab
penetrations and areas with floor loadings exceeding a live load of 70 lbs./s.f.

8. Locations and details of all plumbing fixtures; sinks, drinking fountains,
etc.

9. Location and specifications of floor coverings, e.g., vinyl tile, carpet,
ceramic tile, etc.

10. Finish schedule plan indicating wall covering, paint or paneling with paint
colors referenced to standard color system.

11. Details and specifications of special millwork, glass partitions, rolling
doors and grilles, blackboards, shelves, etc.

12. Hardware schedule indicating door number keyed to plan, size, hardware
required including butts, latchsets or locksets, closures, stops, and any
special items such as thresholds, soundproofing, etc. Keying schedule is
required.

13. Verified dimensions of all built-in equipment (file cabinets, lockers, plan
files, etc).


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14. Location of any special soundproofing requirements.

15. All drawings to be uniform size (30" X 42") and shall incorporate the
standard project electrical and plumbing symbols and be at a scale of 1/8" = 1'
or larger.

16. Drawing submittal shall include one sepia and one blue line print of each
drawing.


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                                    EXHIBIT C

                                LANDLORD SERVICES

                                 RESERVOIR PLACE

I.    CLEANING:

            Cleaning and janitor services as provided below:

      A.    OFFICE AREAS:

            Daily: (Monday through Friday, inclusive, holidays excepted).

            1.    Empty all waste receptacles and ashtrays and remove waste
                  material from the Premises; wash receptacles as necessary.

            2.    Sweep and dust mop all uncarpeted areas using a dust-treated
                  mop.

            3-    Vacuum all rugs and carpeted areas.

            4.    Hand dust and wipe clean with treated cloths all horizontal
                  surfaces, including furniture, office equipment, window sills,
                  door ledges, chair rails, and convector tops, within normal
                  reach.

            5.    Wash clean all water fountains and sanitize.

            6.    Move and dust under all desk equipment and telephones and
                  replace same (but not computer terminals, specialized
                  equipment or other materials).

            7.    Wipe clean all chrome and other bright work.

            8.    Hand dust grill work within normal reach.

            9.    Main doors to premises shall be locked and lights shut off
                  upon completion of cleaning.

            Weekly:

            1.    Dust coat racks and the like.

            2.    Spot clean entrance doors, light switches and doorways.


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            Quarterly:

            1.    Render high dusting not reached in daily cleaning to include:

                  a)    dusting all pictures, frames, charts, graphs and similar
                        wall hangings.

                  b)    dusting of all vertical surfaces, such as walls,
                        partitions, doors and door frames, etc.

                  c)    dusting all pipes, ducts and moldings.

                  d)    dusting of all vertical blinds.

                  e)    dust all ventilating, air conditioning, louvers and
                        grills.

            2.    Spray buff all resilient floors.


      B.    LAVATORIES:

            Daily: (Monday through Friday, inclusive, holidays excepted).

            1.    Sweep and damp mop.

            2.    Clean all mirrors, powder shelves, dispensers and receptacles,
                  bright work, flushometers, piping and toilet seat hinges.

            3.    Wash both sides of all toilet seats.

            4.    Wash all basins, bowls and urinals.

            5.    Dust and clean all powder room fixtures.

            6.    Empty and clean paper towel and sanitary disposal receptacles.

            7.    Remove waste paper and refuse.

            8.    Refill tissue holders, soap dispensers, towel dispensers,
                  sanitary dispensers; materials to be furnished by Landlord,


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            Monthly:

            1.    Machine scrub lavatory floors.

            2.    Wash all partitions and tile walls in lavatories.

            3.    Dust all lighting fixtures and grills in lavatories.

      C.    MAIN LOBBIES, ELEVATORS, STAIRWELLS AND COMMON CORRIDORS:

            Daily: (Monday through Friday, inclusive, holidays excepted).

            1.    Sweep and damp mop all floors, empty and clean waste
                  receptacles, dispose of waste.

            2.    Clean elevators, wash or vacuum floors, wipe down walls and
                  doors.

            3.    Spot clean any metal work inside lobbies.

            4.    Spot clean any metal work surrounding building entrance doors.

            5.    Sweep all stairwells and dust handrails.

            Monthly:

            1.    All resilient tile floors in public areas to be spray buffed.


      D.    WINDOW CLEANING:

            All exterior windows shall be washed on the inside and outside
            surfaces no less than three (3) times per year.

II.   HVAC:

      A.    Heating, ventilating and air conditioning equipment will be provided
            with sufficient capacity to accommodate a maximum population density
            of one (1) person per one hundred fifty (150) square feet of useable
            floor area served, and a combined lighting and standard electrical
            load of 3.0 watts per square foot of useable floor area. In the
            event Tenant introduces into


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            the Premises personnel or equipment which overloads the system's
            ability to adequately perform its proper functions, Landlord shall
            so notify Tenant in writing and supplementary system(s) may be
            required and installed by Landlord at Tenant's expense, if within
            fifteen (15) days Tenant has not modified its use so as not to cause
            such overload.

            Operating criteria of the basic system are in accordance with the
            Massachusetts Energy Code and shall not be less than the following:

             i)    Cooling season indoor conditions of not in excess of 78
                   degrees Fahrenheit when outdoor conditions are 91 degrees
                   Fahrenheit drybulb and 73 degrees Fahrenheit wetbulb.

             ii)   Heating season minimum room temperature of 70 degrees
                   Fahrenheit when outdoor conditions are 6 degrees Fahrenheit
                   drybulb.

      B.    Landlord shall provide heating, ventilating and air conditioning as
            normal seasonal charges may require during Normal Building Operating
            Hours (8:00 a.m. to 6:00 p.m., Monday through Friday, and 8:00 a.m.
            to 1:00 p.m. on Saturdays, legal holidays in all cases excepted).

            If Tenant shall require air conditioning (during the air
            conditioning season) or heating or ventilating during any season
            outside Normal Building Operating Hours, Landlord shall use
            landlord's best efforts to furnish such services for the area or
            areas specified by written request of Tenant delivered to the
            Building Superintendent or the Landlord before 3:00 p.m. of the
            business day preceding the extra usage. For such services, Tenant
            shall pay Landlord, as additional rent, upon receipt of billing, a
            sum equal to the cost incurred by Landlord.

III.  ELECTRICAL SERVICES:

      A.    Landlord shall provide electric power for a combined load of 3.0
            watts per square foot of useable area for lighting and for office
            machines through standard receptacles for the typical office space.

      B.    Landlord, at its option, may require separate metering and direct
            billing to Tenant for the electric power required for any special
            equipment (such as computers and reproduction equipment) that
            requires either 3-phase electric power or any voltage other than
            120, or for any other usage in excess of 3.0 watts per square foot.


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       C.    Landlord will furnish and install, at Tenant's expense, all
             replacement lighting tubes, lamps and ballasts required by Tenant.
             Landlord will clean lighting fixtures on a regularly scheduled
             basis at Tenant's expense.

IV.   ELEVATORS:

            Provide passenger elevator service.

V.    WATER:

            Provide hot water for lavatory purposes and cold water for drinking,
            lavatory and toilet purposes.

VI.   CARD ACCESS SYSTEM:

            Landlord will provide a card access system at one entry door of the
            building.


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                                    EXHIBIT D

                                    PREMISES


                              [GRAPHIC: FLOOR PLAN]

2,517 RSF

RESERVOIR PLACE II
1601 TRAPELO ROAD - SECOND FLOOR                           [GRAPHIC]
WALTHAM, MA
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                                    EXHIBIT F

                              INTENTIONALLY OMITTED


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                                    EXHIBIT G

                               LIST OF MORTGAGEES

      Security Agreement and Mortgage Deed, dated 10/30/96 recorded in the South
Middlesex Registry of Deeds at Book 26791, Page 101, affected by Amended and
Restated Mortgage Deed from Landlord to Teachers Insurance and Annuity
Association of America, dated 11/3/98 recorded with said Deeds, said mortgagee
having an address Attn: Joan Herman, Sr. Investment Analyst, 730 Third Avenue,
New York, NY 10017.


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