LEASE

                                     BETWEEN

                     SILVERSTREAM SOFTWARE, INC., AS TENANT

                                       AND

                   BCIA NEW ENGLAND HOLDINGS LLC, AS LANDLORD

                   2 FEDERAL STREET, BILLERICA, MASSACHUSETTS


<PAGE>


                                TABLE OF CONTENTS
                                -----------------
                                                                           PAGE
                                                                           ----

ARTICLE 1 BASIC DATA; DEFINITIONS.........................................  4

   1.1   Basic Data.......................................................  4
   1.2   Definitions......................................................  5
   1.3   Enumeration of Exhibits..........................................  7

ARTICLE 2 PREMISES AND APPURTENANT RIGHTS.................................  7

   2.1   Lease of Premises................................................  7
   2.2   Appurtenant Rights...............................................  7

ARTICLE 3 BASIC RENT......................................................  7

   3.1   Payment..........................................................  7

ARTICLE 4 COMMENCEMENT AND CONDITION......................................  7

   4.1   Commencement Date................................................  7
   4.2   Preparation of the Premises......................................  8
   4.3   Early Entry......................................................  8

ARTICLE 5 USE OF PREMISES.................................................  9

   5.1   Permitted Use....................................................  9
   5.2   Installations and Alterations by Tenant..........................  9
   5.3   Extra Hazardous Use.............................................. 10
   5.4   Hazardous Materials.............................................. 10

ARTICLE 6 ASSIGNMENT AND SUBLETTING....................................... 11

   6.1   Prohibition...................................................... 11
   6.2   Acceptance of Rent............................................... 11
   6.3   Excess Payments.................................................. 12
   6.4   Further Requirements............................................. 12

ARTICLE 7 RESPONSIBILITY FOR REPAIRS AND CONDITION........................ 12

   7.1   Landlord Repairs................................................. 12
   7.2   Tenant Repairs................................................... 13
   7.3   Floor Load - Heavy Machinery..................................... 13
   7.4   Electricity Service.............................................. 14
   7.5   Interruption of Service.......................................... 14

ARTICLE 8 REAL ESTATE TAXES............................................... 15

   8.1   Payments on Account of Real Estate Taxes......................... 15
   8.2   Abatement........................................................ 15

ARTICLE 9 OPERATING AND UTILITY EXPENSES.................................. 16

   9.1   Definitions...................................................... 16
   9.2   Tenant's Payment of Operating Expenses........................... 16
   9.3   Tenant's Audit Right............................................. 16

ARTICLE 10 INDEMNITY AND PUBLIC LIABILITY INSURANCE....................... 17

   10.1     Tenant's Indemnity............................................ 17
   10.2     Tenant Insurance.............................................. 17
   10.3     Tenant's Risk................................................. 17
   10.4     Landlord's Indemnity.......................................... 17
   10.5     Waiver of Subrogation......................................... 17

ARTICLE 11 FIRE, EMINENT DOMAIN, ETC...................................... 18

   11.1     Landlord's Right of Termination............................... 18
   11.2     Restoration; Tenant's Right of Termination.................... 18
   11.3     Landlord's Insurance.......................................... 18
   11.4     Abatement of Rent............................................. 18
   11.5     Condemnation Award............................................ 18

ARTICLE 12 HOLDING OVER; SURRENDER........................................ 19

   12.1     Holding Over.................................................. 19
   12.2     Surrender of Premises......................................... 19

ARTICLE 13 RIGHTS OF MORTGAGEES; TRANSFER OF TITLE........................ 19

   13.1     Rights of Mortgagees.......................................... 19
   13.2     Assignment of Rents and Transfer of Title..................... 19
   13.3     Notice to Mortgagee........................................... 20

                                       1
<PAGE>

ARTICLE 14 DEFAULT; REMEDIES.............................................. 20

   14.1     Tenant's Default.............................................. 20
   14.2     Landlord's Remedies........................................... 22
   14.3     Additional Rent............................................... 23
   14.4     Landlord's Remedying Tenant Defaults.......................... 23
   14.5     Remedies Cumulative........................................... 23
   14.6     Attorneys' Fees............................................... 23
   14.7     Waiver........................................................ 23
   14.8     Security Deposit.............................................. 23
   14.9     Landlord's Default............................................ 24
   14.10    Tenant Remedying Landlord's Default........................... 24
   14.11    Independent Covenant.......................................... 24

ARTICLE 15 MISCELLANEOUS PROVISIONS....................................... 24

   15.1     Rights of Access.............................................. 24
   15.2     Covenant of Quiet Enjoyment................................... 24
   15.3     Landlord's Liability.......................................... 25
   15.4     Estoppel Certificate.......................................... 25
   15.5     Brokerage..................................................... 25
   15.6     Rules and Regulations......................................... 25
   15.7     Invalidity of Particular Provisions........................... 25
   15.8     Provisions Binding, Etc....................................... 25
   15.9     Recording..................................................... 26
   15.10    Notice........................................................ 26
   15.11    When Lease Becomes Binding; Entire Agreement; Modification.... 26
   15.12    Paragraph Headings and Interpretation of Sections............. 26
   15.13    Dispute Resolution............................................ 26
   15.14    Waiver of Jury Trial.......................................... 26
   15.15    Time Is of the Essence........................................ 26
   15.16    Multiple Counterparts......................................... 26
   15.17    Governing Law................................................. 26
   15.18    Roof Rights................................................... 27
   15.19    Ownership; Prior Tenant....................................... 27
   15.20    Authority..................................................... 27
   15.21    Warranties.................................................... 27


                                       2
<PAGE>


Exhibits

         Exhibit A.........Legal Description of Land
         Exhibit B.........Site Plan of Building
         Exhibit C.........Schedule of Landlord's Furnishings and Equipment
         Exhibit D.........Operating Expenses
         Exhibit E.........Rules and Regulations
         Exhibit F.........Appraisers' Determination of Fair Market Rent
         Exhibit G.........Form of Subordination, Non-Disturbance and
                           Attornment Agreement
         Exhibit H ........Form of Letter of Credit
         Exhibit I.........Form of Notice of Lease




                                       3
<PAGE>



                                    L E A S E

     THIS LEASE is dated as of_______________, 1999 between the Landlord and the
Tenant named below, and is of space in the Building described below.


                                   ARTICLE 1

                            BASIC DATA; DEFINITIONS
                            -----------------------

     1.1 BASIC DATA.  Each reference in this Lease to any of the following terms
shall be  construed  to  incorporate  the data for that  term set  forth in this
Section:


         Landlord:  BCIA New England Holdings LLC, a Delaware limited  liability
         company.

         Landlord's Address:  c/o Boston Capital Institutional Advisors LLC, One
         Boston Place, Boston, Massachusetts 02108.

         Tenant:  Silverstream Software, Inc., a Delaware corporation.

         Tenant's Address:  2 Federal Street, Billerica, Massachusetts.

         Property: The  land located in Billerica, Massachusetts,  together with
         the Building and other  improvements  thereon, all as more particularly
         described in Exhibit A attached hereto.

         Building:  The  two-story  building  commonly  known and  numbered as 2
         Federal Street, agreed to be  100,000 rentable square feet, as shown on
         the site  plan  attached  hereto  as  Exhibit  B  together  with all of
         Landlord's Furnishings and Equipment.

         Premises: The entire Property,  including the Land and the Building, as
         shown on the site plan attached hereto as Exhibit B.

         Basic Rent: The Basic Rent for the Term is as follows:
<TABLE>
<CAPTION>


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

                     RENTAL PERIOD                              ANNUAL BASIC RENT              MONTHLY PAYMENT
-------------------------------------------------------- --------------------------------- -------------------------
<S>                                                      <C>                               <C>

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

From the Commencement Date to February 28, 2001.                   $800,000.00                   $ 66,666.67
-------------------------------------------------------- --------------------------------- -------------------------
-------------------------------------------------------- --------------------------------- -------------------------

From March 1, 2001 to February 28, 2002.                          $1,200,000.00                  $100,000.00

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

From March 1, 2002 to February 28, 2006.                          $1,375,000.00                  $114,583.33

-------------------------------------------------------- --------------------------------- -------------------------
</TABLE>

     If Tenant exercises the Extension Option as provided herein, then the Basic
Rent for the Extension Term shall be the greater of (i) $1,375,000.00 per annum,
and (ii) the Fair Market Rent. As used herein, the term "Fair Market Rent" means
the Basic Rent as  determined:  (i) by  agreement  between  Landlord and Tenant,
negotiating  in good  faith,  no later  than  thirty  (30) days  after  Tenant's
exercise of the Extension  Option but if Tenant  exercises the Extension  Option
prior to March  1,  2005,  then  Landlord  and  Tenant  shall  reach  agreement,
negotiating in good faith,  no later than March 31, 2005 (and Landlord shall not
be required to so  negotiate  prior to March 1, 2005),  or (ii) if Landlord  and
Tenant shall not have agreed upon the Fair Market Rent by said date as aforesaid
(an  "Impasse"),  then Fair Market Rent for the Extension Term shall be fixed by
means of an Appraisers'  Determination as more particularly described in Exhibit
F hereto.

                                       4
<PAGE>

          Security Deposit:  $300,000 for the first three (3) years of the Term,
          thereafter  being  reduced to $150,000 for the  remainder of the Term.
          The  Security  Deposit  shall  be in the form of a  Letter  of  Credit
          satisfying  the  requirements,  and  to be  held  and  disposed  of as
          provided in,  Section  14.8.  Notwithstanding  any contrary  provision
          herein, the  above-referenced  reduction in the amount of the Security
          Deposit at the end of the third year of the Term shall not be effected
          if (i)  Landlord  has  previously  drawn  upon the  Letter  of  Credit
          pursuant hereto, or (ii) a Default of Tenant has occurred, and in each
          such event the Security Deposit shall remain $300,000 for the duration
          of the Term.

          Commencement Date: March 1, 2000, subject to the provisions of Section

4.1  HEREIN REGARDING EARLY ENTRY.

          TERM: Six (6) years,  commencing on the Commencement Date and expiring
          at the close of the day on February 28, 2006.  The Term shall  include
          the Extension Term provided that Tenant exercises the Extension Option
          strictly in accordance with this Lease.

          EXTENSION  OPTION:  Provided  that  Tenant  is  not  then  in  default
          hereunder,  Tenant  shall  have the  option to extend the Term for the
          Extension Term,  with such Extension  Option to be exercised by Tenant
          delivering to Landlord  written notice thereof (the "Tenant  Extension
          Notice") not later than March 1, 2005.

          EXTENSION TERM:  Subject to Tenant exercising the Extension Option, in
          accordance with the provisions of this Lease, the Extension Term shall
          be for a period  of five (5)  years,  commencing  on March 1, 2006 and
          expiring on February 28, 2011.  The  Extension  Term shall be upon all
          the same terms, covenants and conditions as the Term, except (i) as to
          Basic Rent,  which shall be  determined  as set forth above,  and (ii)
          that there shall be no further  extension  rights  unless agreed to in
          writing by Landlord.

          INITIAL     GENERAL     LIABILITY     INSURANCE:     $5,000,000    per
          occurrence/$10,000,000  aggregate (combined single limit) for property
          damage, bodily injury or death.

          PERMITTED  USES:   General  offices  and  research  and   development,
          warehousing and distribution, light manufacturing.

          LANDLORD'S CONTRIBUTION: $600,000, subject to Section 4.2 below.

1.2  DEFINITIONS.  When used in Lease,  the  capitalized  terms set forth  below
     shall bear the meanings set forth below.

          ADEQUATE ASSURANCE: As defined in Section 14.1.

          ADEQUATE ASSURANCE OF FUTURE PERFORMANCE: As defined in Section 14.1.

          ADDITIONAL  RENT:  All charges and sums payable by Tenant as set forth
          in this Lease, other than and in addition to Basic Rent.

          AGENT:  BCIA  Property  Management  LLC or such other person or entity
          from time to time designated by Landlord.

          ALTERATIONS: As defined in Section 5.2.

          BANKRUPTCY CODE: As defined in Section 14.1.

          BASIC RENT: As defined in Section 1.1.

          BROKER: Meredith & Grew, Inc. and Spaulding & Slye, as co-brokers.

          APPRAISERS'  DETERMINATION:  As defined in Exhibit F attached  hereto.

          BUILDING: As defined in Section 1.1.

          BUSINESS DAY: All days except Saturdays,  Sundays, and other days when
          national  banks in the state in which the  property is located are not
          open for business.

          COMMENCEMENT DATE:  As defined in Section 4.1.

          COST OF TENANT'S WORK: As defined in Section 4.2.

          DEFAULT OF TENANT:  As defined in Section 14.1.

          ENVIRONMENTAL CONDITION: Any disposal, release or threat of release of
          Hazardous  Materials on, from or about the Building or the Property or
          storage of Hazardous  Materials  on, from or about the Building or the
          Property.

          ENVIRONMENTAL   LAWS:   Any  federal,   state  and/or  local  statute,
          ordinance,  bylaw,  code,  rule  and/or  regulation  now or  hereafter
          enacted,  pertaining to any aspect of the environment or human health,
          including,  without  limitation,  Chapter 21C, Chapter 21D and Chapter
          21E  of  the  General  Laws  of  Massachusetts   and  the  regulations
          promulgated   by  the   Massachusetts   Department  of   Environmental
          Protection, the Comprehensive Environmental Response, Compensation and
          Liability  Act  of  1980,  42  U.S.C.ss.9601  et  seq.,  the  Resource
          Conservation  and Recovery Act of 1976, 42  U.S.C.ss.6901 et seq., the
          Toxic  Substances  Control Act, 15  U.S.C.ss.2061 et seq., the Federal
          Clean Water Act, 33  U.S.C.ss.1251,  and the Federal Clean Air Act, 42
          U.S.C.ss.7401 et seq.

                                       5
<PAGE>

          EVENT OF BANKRUPTCY:  As defined in Section 14.1.

          EXTENSION OPTION:  As defined in Section 1.1.

          EXTENSION TERM:  As defined in Section 1.1.

          FAIR MARKET RENT:  As defined in Section 1.1.

          Fields Business Park means the business park in which the Premises are
          located.

          FORCE MAJEURE:  Collectively and individually,  strikes or other labor
          trouble, fire or other casualty,  acts of God, governmental preemption
          of priorities or other controls in connection with a national or other
          public  emergency or shortages  of fuel,  supplies or labor  resulting
          therefrom,  or any other cause, whether similar or dissimilar,  beyond
          the reasonable control of the party required to perform an obligation,
          excluding financial constraints of such party.

          HOLDER:  As defined in Section 13.1.

          HAZARDOUS  MATERIALS:  Shall  mean each and every  element,  compound,
          chemical mixture,  contaminant,  pollutant,  material,  waste or other
          substance  which is defined,  determined or identified as hazardous or
          toxic under any Environmental Law, including,  without limitation, any
          "oil," "hazardous  material," "hazardous waste," "hazardous substance"
          or  "chemical  substance  or  mixture",  as the  foregoing  terms  (in
          quotations) are defined in any Environmental Laws.

          INITIAL GENERAL LIABILITY INSURANCE:  As defined in Section 1.1.

          LAND:  The land that constitutes a portion of the Property.

          LANDLORD:  As defined in Section 1.1.

          LANDLORD AGENTS: Landlord's partners, members, shareholders, officers,
          directors, managers, employees, agents, invitees or contractors.

          LANDLORD'S ADDRESS: As defined in Section 1.1.

          LANDLORD'S CONSTRUCTION REPRESENTATIVE:  As defined in Section 1.1.

          LANDLORD'S CONTRIBUTION:  As defined in Section 1.1.

          LANDLORD'S FURNISHINGS AND EQUIPMENT: As defined in Exhibit G attached
          hereto.

          LETTER OF CREDIT: As defined in Section 14.8.

          MORTGAGE:  As defined in Section 13.1.

          NEW LAWS:  As defined in Section 7.2(a).

          NEW LAW WORK:  As defined in Section 7.2(a).

          OPERATING EXPENSES:  As defined in Section 9.1.

          OPERATING YEAR:  As defined in Section 9.1.

          PERMITTED USES: As defined in Section 1.1.

          PREMISES:  As defined in Section 1.1.

          PROPERTY:  As defined in Section 1.1.

          RENT:  Basic Rent and Additional Rent, collectively.

          RULES AND REGULATIONS:  As defined in Section 2.2.

          SECURITY DEPOSIT:  As defined in Section 1.1.

          SNDA:  As defined in Section 13.1.

          SUCCESSOR:  As defined in Section 13.1.

          STRUCTURE:  As defined in Section 7.1.

          TAXES:  As defined in Section 8.1.

          TAX YEAR:  As defined in Section 8.1.

          TENANT:  As defined in Section 1.1.

          TENANT EXTENSION NOTICE: As defined in Section 1.1.

          TENANT'S ADDRESS:  As defined in Section 1.1.

          TENANT'S  AGENTS:  means  Tenant's  partners,  members,  shareholders,
          officers,   directors,   managers,   employees,  agents,  invitees  or
          contractors.

                                       6
<PAGE>

          TENANT'S CONSTRUCTION REPRESENTATIVE:  As defined in Section 1.1.

          TENANT'S PLANS:  As defined in Section 4.2.

          TENANT'S REMOVABLE PROPERTY:  As defined in Section 5.2.

          TENANT'S ROOFTOP EQUIPMENT:  As defined in Section 15.18(a).

          TENANT'S WORK: As defined in Section 4.2.

          TERM:  As defined in Section 1.1.

1.3  ENUMERATION OF EXHIBITS.  The following  Exhibits are attached hereto,  are
     made a part of this Lease, are incorporated herein by reference, and are to
     be treated as a part of this Lease for all purposes. Undertakings contained
     in such Exhibits are agreements on the part of Landlord and Tenant,  as the
     case may be, to perform the obligations stated therein.

          Exhibit A - Legal Description of Land
          Exhibit B - Site Plan of Building
          Exhibit C - Schedule of Landlord's  Furnishings  and Equipment
          Exhibit D - Operating   Expenses
          Exhibit E - Rules and Regulations
          Exhibit F - Appraisers' Determination of Fair Market Rent
          Exhibit G - Form of Subordination, Non-Disturbance and Attornment
                      Agreement
          Exhibit H - Form of Letter of Credit
          Exhibit I - Form of Notice of Lease

                                   ARTICLE 2

                         PREMISES AND APPURTENANT RIGHTS

2.1  LEASE OF  PREMISES.  Landlord  hereby  leases to Tenant and  Tenant  hereby
     leases  from  Landlord  the  Premises  for the Term and upon the  terms and
     conditions hereinafter set forth.

2.2  APPURTENANT RIGHTS. Tenant shall have, as appurtenant to the Premises,  the
     non-exclusive  right to use,  and permit its invitees to use in common with
     others entitled thereto,  the easements,  rights of way or other rights, if
     any,  which  are  appurtenant  to the  Property  pursuant  to any  recorded
     documents evidencing such easements or rights; but such rights shall always
     be  subject to such  conditions,  rules and  regulations  from time to time
     established   by  Landlord   pursuant  to  Section  15.6  (the  "Rules  and
     Regulations")  and to the right of  Landlord to  designate  and change from
     time to time such appurtenant  rights pursuant to the terms of the recorded
     documents  evidencing  such  rights and to grant such  easements  and other
     encumbrances so long as the same do not materially and adversely  interfere
     with the use of the Premises by Tenant.

                                   ARTICLE 3

                                   BASIC RENT

3.1  PAYMENT.

          (a)  Tenant  agrees  to pay the  Basic  Rent  and  Additional  Rent to
          Landlord,  or as directed by Landlord,  commencing on the Commencement
          Date, without offset, abatement (except as provided in Section 7.5 and
          Section  11.4),  deduction  or demand.  Basic Rent shall be payable in
          equal monthly  installments,  in advance, on the first day of each and
          every  calendar  month  during the Term of this Lease,  to Landlord at
          Landlord's  Address or at such other place as Landlord shall from time
          to time designate by notice,  in lawful money of the United States. In
          the  event  that  any  installment  of  Basic  Rent  or any  regularly
          scheduled  payment of Additional Rent is not paid within five (5) days
          of when due,  Tenant  shall pay,  in  addition  to any  charges  under
          Section 14.4, at Landlord's  request an administrative fee equal to 4%
          of the overdue payment. Landlord and Tenant agree that all amounts due
          from Tenant under or in respect of this Lease,  whether  labeled Basic
          Rent,  Additional  Rent or  otherwise,  shall be  considered as rental
          reserved  under  this  Lease  for  all  purposes,   including  without
          limitation  regulations  promulgated  pursuant to the Bankruptcy Code,
          and including further without limitation Section 502(b) thereof.

          (b) Basic Rent for any  partial  month shall be  pro-rated  on a daily
          basis,  and if the first day on which Tenant must pay Basic Rent shall
          be other than the first day of a  calendar  month,  the first  payment
          which Tenant shall make to Landlord shall be equal to a  proportionate
          part of the monthly  installment  of Basic Rent for the partial  month
          from the first day on which Tenant must pay Basic Rent to the last day
          of the month in which such day occurs,  plus the  installment of Basic
          Rent for the succeeding calendar month.

                                   ARTICLE 4

                           COMMENCEMENT AND CONDITION

4.1  COMMENCEMENT DATE. The Commencement Date shall be the first to occur of:

          (a) March 1, 2000, or

          (b)  the day Tenant's personnel occupy all or any part of the Premises
               for the conduct of its business prior to the Commencement Date.

                                       7
<PAGE>

4.2  PREPARATION OF THE PREMISES.

          (a)  Tenant shall prepare, at its sole cost and expense (against which
               the Landlord's Contribution may be applied), plans for the layout
               of the improvements which Tenant desires to have performed in the
               Premises  (the  "Tenant's   Plans").   Tenant's  Plans  shall  be
               submitted  to  Landlord  for its  approval,  and  Landlord  shall
               approve  or  disapprove  of  Tenant's  Plans,  in its  reasonable
               discretion,  within ten (10) Business Days of receiving  them. No
               work shall be conducted by Tenant until  Tenant's Plans have been
               fully approved by Landlord.  Any disapproval shall be accompanied
               by a  reasonably  specific  statement  of  reasons  therefor.  At
               Tenant's  sole cost and  expense  (against  which the  Landlord's
               Contribution  may be applied),  Tenant shall cause Tenant's Plans
               to be revised  in a manner  sufficient  to remedy the  Landlord's
               objections and/or respond to the Landlord's concerns and for such
               revised plans to be redelivered  to Landlord,  and Landlord shall
               either approve or disapprove  Tenant's  revised plans within five
               (5) Business  Days  following  the date of  submission.  Tenant's
               Plans  shall be stamped by a  Massachusetts-registered  architect
               and  engineer,  such  architect  and  engineer  being  subject to
               Landlord's  reasonable  approval,   and  shall  comply  with  all
               applicable laws, ordinances and regulations  (including,  without
               limitation,  the  applicable  requirements  of the Americans with
               Disabilities  Act  of  1990,  and  the  regulations   promulgated
               thereunder) and the requirements of the Rules and Regulations and
               shall  be in a  form  satisfactory  to  appropriate  governmental
               authorities  responsible  for  issuing  permits,   approvals  and
               licenses required for construction.  Landlord hereby approves the
               following  as  Tenant's  architect:  Maugel  Architects;  and the
               following as Tenant's contractor: Spaulding & Slye.

          (b)  Promptly after approval of Tenant's Plans,  Tenant shall exercise
               all  reasonable  efforts to complete the work  specified  therein
               necessary  to  prepare  the   Premises  for  Tenant's   occupancy
               ("Tenant's  Work").  All  Tenant's  Work  shall be  completed  in
               accordance  with the  requirements  set  forth in the  Rules  and
               Regulations.  Landlord  shall  reimburse  Tenant  for  the  costs
               incurred by the Tenant with respect to the design and performance
               of Tenant's  Work (the "Cost of Tenant's  Work") up to the amount
               of Landlord's Contribution,  subject to the provisions hereof. To
               the extent that the Cost of Tenant's Work exceeds the  Landlord's
               Contribution,  Tenant  shall  be  entirely  responsible  for such
               excess.  Landlord's  Contribution shall be payable by Landlord to
               Tenant   (or,  at   Tenant's   election,   directly  to  Tenant's
               contractor) upon written  requisition to Landlord in installments
               according to reasonable construction  disbursement procedures, as
               Tenant's Work  progresses.  In any case,  prior to payment of any
               such  installment  Tenant  shall  deliver  to  Landlord a written
               request,  which  request shall be given no more  frequently  than
               once every thirty (30) days, for such  disbursement,  which shall
               be accompanied  by: (i) invoices for Tenant's Work covered by any
               previous  requisition;  (ii)  copies of partial  lien  waivers or
               final  lien  waivers  (in the case of a final  installment);  and
               (iii) a  certificate  signed  by the  Tenant's  architect  and an
               officer of the Tenant  certifying that Tenant's Work  represented
               by the aforementioned  invoices has been completed  substantially
               in accordance with Tenant's Plans and that the remaining  portion
               of Landlord's  Contribution  is sufficient to pay in full for the
               completion  of  Tenant's  Work.  If at any  time  the  amount  of
               Landlord's  Contribution is insufficient to pay for the remaining
               amount of Tenant's Work, then Tenant shall pay from its own funds
               all  further  sums   necessary  to  enable  Tenant  and  Tenant's
               architect to again make the  certification  required  under (iii)
               above.

          (c)  Except for Tenant's  Work, the Premises are being leased in their
               AS  IS   condition.   The  Premises  are  being  leased   WITHOUT
               REPRESENTATION OR WARRANTY by Landlord.  Tenant acknowledges that
               it has  inspected  the  Premises and common areas of the Building
               and,  except for  Tenant's  Work,  has found  them  satisfactory,
               except  that  because  of  current  weather,   it  has  not  been
               determined whether the air conditioning units are in good working
               condition.  Landlord  and Tenant  agree that they will review the
               operation  of the air  conditioning  units  during  the months of
               June, July and August of 2000 and by August 31, 2000 determine if
               such  units  are in good  working  condition.  If such  units are
               determined  to  not  be  in  good  working  condition,  then,  at
               Landlord's  sole cost and expense,  Landlord agrees to cause such
               units to be placed in good working  condition.  If such units are
               determined to be in good working condition, then such units shall
               be deemed to be accepted by Tenant.

                                       8
<PAGE>

4.3  EARLY ENTRY. Landlord agrees to allow Tenant to have access to the Premises
     after the execution hereof for design,  space planning,  inspection and the
     like  (collectively,  "Non-Construction  Work") and for installation of its
     telecommunications  equipment and to install its  fixtures,  all subject to
     obtaining  Landlord's  approval of Tenant's  plans  pursuant to Section 4.2
     herein.  Prior to any entry  onto the  Premises,  Tenant  shall  deliver to
     Landlord  certificates  of  insurance  evidencing  the  coverages  required
     herein.  With respect to the period  commencing  upon any such early entry,
     all non-payment provisions of this Lease shall apply. In addition, upon the
     commencement of any such installation or construction, Tenant shall pay for
     all utilities,  trash removal, and, only if requested by Tenant during this
     period  prior  to  the  Commencement  Date,   security  patrols.   Tenant's
     obligation  to pay all  other  Operating  Expenses  and all  other  payment
     obligations under this Lease shall commence on the Commencement Date.

                                   ARTICLE 5

                                 USE OF PREMISES

5.1  PERMITTED USE.

          (a)  Tenant  agrees that the  Premises  shall be used and  occupied by
               Tenant  only for  Permitted  Uses and for no  other  use  without
               Landlord's express written consent.

          (b)  Tenant agrees to conform to the following  provisions  during the
               Term of this Lease:

          (i)  Tenant shall cause all freight to be delivered to or removed from
               the Building and the  Premises in  accordance  with the Rules and
               Regulations established by Landlord therefor;

          (ii) Tenant will not place on the exterior of the Building  (including
               both  interior  and  exterior  surfaces  of  doors  and  interior
               surfaces of windows), any sign, symbol, advertisement or the like
               visible to public view outside of the Premises without Landlord's
               prior written  consent,  which consent shall not be  unreasonably
               withheld or delayed.  Landlord will not withhold  consent for any
               signs or lettering  provided that such signs or lettering  comply
               with law and  conform to any sign  standards  of Fields  Business
               Park,  and provided  that Tenant has submitted to Landlord a plan
               or sketch in  reasonable  detail  (showing,  without  limitation,
               size, color, location, materials and method of affixation) of the
               sign or lettering;

          (iii)Tenant shall not perform any act or carry on any  practice  which
               may injure the  Premises,  or cause any  offensive  odors or loud
               noise or constitute a nuisance or a menace; and

          (iv) Tenant  shall,  in its  use  of the  Premises,  comply  with  the
               requirements  of all  applicable  governmental  laws,  rules  and
               regulations,  including,  without limitation,  the Americans With
               Disabilities Act of 1990 and the regulations of the Massachusetts
               Architectural Access Board.

5.2  INSTALLATIONS AND ALTERATIONS BY TENANT.

          (a)  Tenant shall make no alterations,  additions (including,  for the
               purposes  hereof,   wall-to-wall   carpeting),   or  improvements
               (collectively,  "Alterations")  in or to the Premises  (including
               any Alterations  necessary for Tenant's initial  occupancy of the
               Premises) without Landlord's prior written consent, which consent
               shall not be  unreasonably  withheld or delayed  with  respect to
               non-structural  Alterations  that  do  not  materially  adversely
               affect or involve the Building's life safety,  HVAC,  electrical,
               plumbing or mechanical systems or any other Building systems. Any
               Alterations shall be in accordance with the Rules and Regulations
               in effect with respect thereto and with plans and  specifications
               meeting the  requirements  set forth in the Rules and Regulations
               and approved in advance by Landlord. All Alterations shall be (i)
               be performed in a good and  workmanlike  manner and in compliance
               with all applicable  laws,  ordinances and  regulations;  (ii) be
               made at Tenant's sole cost and expense;  (iii) at the election of
               Landlord,  become  part  of the  Premises  and  the  property  of
               Landlord except for all articles of personal  property,  business
               fixtures,  machinery,  equipment and furniture owned or installed
               by  Tenant  solely  at its  expense  in the  Premises,  including
               without  limitation,  Tenant's  Rooftop  Equipment  as defined in
               Section 15.18(a)  (collectively,  "Tenant's Removable Property");
               and (iv) be coordinated with any work being performed by Landlord
               in such a manner as not to damage the Building or interfere  with
               the  construction  or operation of the  Building.  At  Landlord's
               request,  Tenant  shall,  before  its  work  is  started,  secure
               assurances  satisfactory to Landlord in its reasonable discretion
               protecting  Landlord against claims arising out of the furnishing
               of labor and materials for the Alterations.  Notwithstanding  the
               foregoing,  Tenant  shall  have  the  right  to make  Alterations
               without Landlord's approval so long as the same (1) do not affect
               the  Structure  as  defined  in  Section  7.1 herein or the roof,
               window frames, outside walls, or building systems of the Building
               and (2) do not have an aggregate cost of more than $50,000 in any
               one year.

                                       9
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               If  any  Alterations  shall  involve  the  removal  of  fixtures,
               equipment  or  other  property  in the  Premises  which  are  not
               Tenant's Removable Property, such fixtures, equipment or property
               shall be  promptly  replaced  by Tenant at its  expense  with new
               fixtures,  equipment  or property of like utility and of at least
               equal quality.

          (b)  Notice is hereby  given,  and Landlord and Tenant  hereby  agree,
               that  Landlord  shall  not be liable  for any labor or  materials
               furnished or to be  furnished to Tenant upon credit,  and that no
               mechanic's  or other lien for any such labor or  materials  shall
               attach to or affect the  reversion or other estate or interest of
               Landlord in and to the Premises, the Building or the Property. To
               the  maximum  extent  permitted  by law,  before such time as any
               contractor commences to perform work on behalf of Tenant,  Tenant
               shall obtain from such  contractor (and any  subcontractors)  and
               shall furnish to Landlord, a written statement  acknowledging the
               provisions  set  forth  in the  immediately  preceding  sentence.
               Tenant  agrees to pay  promptly  when due the entire  cost of any
               work  done  on  behalf  of  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 all or any part of the Property and  immediately  to
               discharge any such liens which may so attach. If, notwithstanding
               the  foregoing,  any lien is filed against all or any part of the
               Property  for work  claimed to have been done for,  or  materials
               claimed  to  have  been  furnished  to,  Tenant  or  its  agents,
               employees or independent  contractors,  Tenant,  at its sole cost
               and expense, shall cause such lien to be dissolved promptly after
               receipt of notice that such lien has been  filed,  by the payment
               thereof or by the filing of a bond  sufficient to accomplish  the
               foregoing.  If Tenant shall fail to discharge  any such lien upon
               notice thereof,  Landlord may, at its option, discharge such lien
               and treat the cost thereof (including attorneys' fees incurred in
               connection  therewith) as Additional Rent payable upon demand, it
               being expressly  agreed that such discharge by Landlord shall not
               be  deemed  to waive or  release  the  default  of  Tenant in not
               discharging  such lien.  Tenant shall indemnify and hold Landlord
               harmless  from and against any and all expenses,  liens,  claims,
               liabilities  and  damages  based  on  or  arising,   directly  or
               indirectly, by reason of the making of any alterations, additions
               or  improvements  by or on behalf of Tenant to the Premises under
               this Section,  which  obligation  shall survive the expiration or
               termination of this Lease.

          (c)  In the course of any work being  performed by Tenant  (including,
               without  limitation,  the "field  installation"  of any  Tenant's
               Removable  Property),  Tenant agrees to use labor compatible with
               that being  employed by Landlord  for work in the  Building or on
               the  Property  or  other  buildings  owned  by  Landlord  or  its
               affiliates  (which term,  for  purposes  hereof,  shall  include,
               without  limitation,  entities  which control or are under common
               control with or are  controlled  by Landlord or, if Landlord is a
               partnership  or  limited  liability  company,  by any  partner or
               member of  Landlord)  and not to employ or permit  the use of any
               labor or otherwise  take any action which might result in a labor
               dispute involving personnel providing services in the Building or
               on the Property pursuant to arrangements made by Landlord.

5.3  EXTRA HAZARDOUS USE. 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  increase  the rate of  property  or
     liability insurance on the Premises or the Property above the standard rate
     applicable  to Premises  being  occupied  for the  Permitted  Uses.  If the
     premium  or rates  payable  with  respect  to any  policy  or  policies  of
     insurance  purchased  by  Landlord  or Agent with  respect to the  Property
     increases  as a result  of any act or  activity  on or use of the  Premises
     during the Term or payment by the insurer of any claim arising from any act
     or neglect of Tenant,  its  employees,  agents,  contractors  or  invitees,
     Tenant shall pay such increase, from time to time, within fifteen (15) days
     after demand therefor by Landlord, as Additional Rent.

5.4  HAZARDOUS MATERIALS.

          (a)  Tenant may use  chemicals  such as  adhesives,  lubricants,  ink,
               solvents  and  cleaning  fluids of the kind and in amounts and in
               the  manner  customarily  found and used in  business  offices in
               order to conduct its business at the Premises and to maintain and
               operate the business  machines  located in the  Premises.  Tenant
               shall not allow, use, store, handle, treat, transport, release or
               dispose of any other Hazardous Materials on or about the Premises
               or the Property without  Landlord's prior written consent,  which
               Landlord may withhold or condition in Landlord's sole discretion.

          (b)  Any handling, treatment, transportation, storage, disposal or use
               of Hazardous  Materials by Tenant in or about the Premises or the
               Property and  Tenant's use of the Premises  shall comply with all
               applicable Environmental Laws.

                                       10
<PAGE>

          (c)  Tenant   shall   indemnify,   defend  upon  demand  with  counsel
               reasonably  acceptable to Landlord,  and hold  Landlord  harmless
               from  and  against,  any  liabilities,  losses  claims,  damages,
               interest, penalties, fines, attorneys' fees, experts' fees, court
               costs,  remediation  costs,  and other expenses which result from
               the use, storage, handling, treatment,  transportation,  release,
               threat of release or disposal of Hazardous  Materials in or about
               the  Premises  or the  Property  by  Tenant or  Tenant's  agents,
               employees, contractors or invitees.

          (d)  Tenant  shall  give  written   notice  to  Landlord  as  soon  as
               reasonably  practicable  of (i)  any  communication  received  by
               Tenant  from  any  governmental  authority  concerning  Hazardous
               Materials which relates to the Premises or the Property, and (ii)
               any Environmental Condition of which Tenant is aware.

          (e)  Landlord  has  provided  to  Tenant a copy of a  certain  Phase I
               Environmental  Site Assessment with respect to the Property dated
               April 30, 1999 prepared by Eckland Consultants Inc., and Landlord
               represents  to Tenant that said report is the only  environmental
               site  assessment  in  Landlord's  possession  with respect to the
               Property.

                                   ARTICLE 6

                            ASSIGNMENT AND SUBLETTING

6.1  PROHIBITION.

          (a)  Except  as  expressly   provided  in  this  Section  6.1,  Tenant
               covenants  and agrees  that  neither  this Lease nor the Term and
               estate hereby granted,  nor any interest herein or therein,  will
               be   assigned   (collaterally,   conditionally   or   otherwise),
               mortgaged, pledged, encumbered or otherwise transferred,  whether
               voluntarily, involuntarily, by operation of law or otherwise, and
               that neither the Premises nor any part thereof will be encumbered
               in any  manner by reason  of any act or  omission  on the part of
               Tenant,  or used or occupied or permitted to be used or occupied,
               by anyone other than Tenant, or for any use or purpose other than
               a Permitted  Use, or be sublet (which term,  without  limitation,
               shall include granting of concessions,  licenses and the like) in
               whole or in part, or be offered or advertised  for  assignment or
               subletting  by Tenant or any  person  acting on behalf of Tenant,
               without,  in each case,  the prior  written  consent of Landlord.
               Without limiting the foregoing, any agreement: (x) which purports
               to relieve  Tenant  from the  obligation  to pay,  or pursuant to
               which a third party agrees to pay on Tenant's behalf,  all or any
               portion of the Basic Rent or  Additional  Rent under this  Lease;
               and/or  (y)  pursuant  to which a third  party  undertakes  or is
               granted  by or on behalf of Tenant the right to assign or attempt
               to assign  this  Lease or sublet or  attempt to sublet all or any
               portion of the Premises,  shall for all purposes hereof be deemed
               to be an assignment  of this Lease and subject to the  provisions
               of this ARTICLE 6. The  provisions  of this  paragraph  (a) shall
               apply to a transfer (by one or more  transfers)  of a controlling
               portion of or interest in the stock or  partnership or membership
               interests or other evidences of equity  interests of Tenant as if
               such transfer were an assignment of this Lease;  provided that if
               equity  interests in Tenant at any time are or become traded on a
               public stock exchange, the transfer of equity interests in Tenant
               on a public  stock  exchange  shall not be  deemed an  assignment
               within the meaning of this Article.

          (b)  The  provisions  of  paragraph  (a) shall not apply to either (x)
               transactions  with an entity into or with which  Tenant is merged
               or  consolidated,  or to which more than 50% of Tenant's stock or
               all or substantially all of Tenant's assets are transferred,  (y)
               transactions  with any entity which  controls or is controlled by
               Tenant or is under common control with Tenant, or (z) assignments
               or subleases to reputable  assignees/sublessees to which Landlord
               consents  in  writing,   such  consent  not  to  be  unreasonably
               withheld, conditioned or delayed.

6.2  ACCEPTANCE  OF RENT.  If this Lease be assigned,  or if the Premises or any
     part thereof be sublet or occupied by anyone other than Tenant,  whether or
     not in violation of the terms and conditions of the Lease, Landlord may, 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, collection or modification of any provisions of this Lease shall
     be deemed a waiver of this  covenant,  or the  acceptance  of the assignee,
     sublessee  or  occupant as a tenant or a release of Tenant from the further
     performance  of covenants on the part of Tenant to be performed  hereunder.
     Any consent by Landlord to a particular assignment, subletting or occupancy
     or other act for which  Landlord's  consent is required under paragraph (a)
     of Section  6.1 shall not in any way  diminish  the  prohibition  stated in
     paragraph (a) of Section 6.1 as to any further such assignment,  subletting
     or occupancy or other act or the continuing liability of the original named
     Tenant. No assignment or subletting hereunder shall relieve Tenant from its
     obligations  hereunder,  and Tenant shall remain fully and primarily liable
     therefor.  Landlord  may  withhold  consent  to  a  particular  assignment,
     subletting or occupancy if the assignment,  sublease or occupancy agreement
     does not provide that the assignee,  sublessee or other occupant  agrees to
     be independently bound by and upon all of the covenants, agreements, terms,
     provisions  and conditions set forth in this Lease on the part of Tenant to
     be kept and performed.

                                       11
<PAGE>

6.3  EXCESS  PAYMENTS.  If Tenant  assigns this Lease or sublets the Premises or
     any portion thereof,  Tenant shall pay to Landlord as Additional Rent fifty
     percent  (50%) of the  amount,  if any,  by which any and all  compensation
     received by Tenant as a result of such  assignment  or  subletting,  net of
     reasonable  expenses  actually  incurred by Tenant in connection  with such
     assignment or  subletting,  exceeds (a) in the case of an  assignment,  the
     Basic Rent and Additional  Rent under this Lease,  and (b) in the case of a
     subletting,  the portion of the Basic Rent and Additional Rent allocable to
     the portion of the Premises subject to such subletting. Such payments shall
     be made on the date the  corresponding  payments  under this Lease are due.
     Notwithstanding the foregoing,  the provisions of this Section shall impose
     no  obligation  on Landlord to consent to an  assignment of this Lease or a
     subletting  of all or a portion of the  Premises.  As used in this Section,
     the term  "reasonable  expenses" means (a) improvement  allowances or other
     economic  concessions  granted by Tenant to the assignee or sublessee;  (b)
     the unamortized costs of initial and subsequent improvements to the subject
     portion of the Premises paid for by Tenant; (c) costs incurred by Tenant to
     buy-out or take over the previous  lease of the assignee or sublessee;  (d)
     all costs  incurred  by Tenant to  advertise  the  subject  portion  of the
     Premises  for  assignment  or  sublease;  and  (e)  arms  length  brokerage
     commissions  and/or  legal  fees  paid by  Tenant  in  connection  with the
     assignment or sublease;

6.4  FURTHER  REQUIREMENTS.  Tenant  shall  reimburse  Landlord  on  demand,  as
     Additional  Rent,  for  any  out-of-pocket   costs  (including   reasonable
     attorneys' fees and expenses)  actually  incurred by Landlord in connection
     with any actual or proposed assignment,  sublease or occupancy agreement or
     other act  described  in  paragraph  (a) of  Section  6.1,  whether  or not
     consummated,  including the reasonable costs of making investigations as to
     the  acceptability of the proposed  assignee or sublessee.  Notwithstanding
     Tenant  entering  into any  assignment,  sublease  or  occupancy  agreement
     pursuant  hereto,  Tenant  shall  remain  primarily  liable  for all of its
     obligations hereunder.  Any assignment,  sublease or occupancy agreement to
     which  Landlord gives its consent shall not be valid or binding on Landlord
     and no assignee,  sublessee or occupant shall take possession of all or any
     portion  of the  Premises,  unless  and  until  Tenant  and  the  assignee,
     sublessee or occupant  executes a consent  agreement in form and  substance
     satisfactory to Landlord in its reasonable  discretion and a fully executed
     counterpart of such  assignment,  sublease or occupancy  agreement.  In the
     event that Landlord  consents to any sublease  under the provisions of this
     Article, any such sublease shall provide that: (i) the term of the sublease
     must end no  later  than  one day  before  the last day of the Term of this
     Lease;  (ii) no  sublease  shall be  valid,  and no  sublessee  shall  take
     possession  of all or any  part of the  Premises  until  a  fully  executed
     counterpart  of such  sublease has been  delivered to Landlord;  (iii) such
     sublease  is subject  and  subordinate  to this Lease;  (iv)  Landlord  may
     enforce the provisions of the sublease,  including collection of rents; (v)
     in the event of termination of this Lease or reentry or repossession of the
     Premises by Landlord, Landlord may, at its sole discretion and option, take
     over all of the right,  title and interest of Tenant,  as sublessor,  under
     such sublease,  and such sublessee shall, at Landlord's  option,  attorn to
     Landlord but nevertheless Landlord shall not (A) be liable for any previous
     act or  omission  of Tenant  under  such  sublease;  (B) be  subject to any
     defense  or offset  previously  accrued in favor of the  sublessee  against
     Tenant; or (C) be bound by any previous  modification of such sublease made
     without  Landlord's  written consent or by any previous  prepayment of more
     than one month's rent.

                                   ARTICLE 7

                    RESPONSIBILITY FOR REPAIRS AND CONDITION

                OF PREMISES; SERVICES TO BE FURNISHED BY LANDLORD

7.1  LANDLORD REPAIRS.

          (a)  Except as otherwise  provided in this Lease,  Landlord  agrees to
               keep in good order,  condition  and repair the  Structure  of the
               Building  (but  specifically  excluding  all life  safety,  HVAC,
               plumbing,  mechanical and electrical systems in the Building). As
               used herein the term "Structure"  means the load bearing portions
               of the  walls,  columns,  beams,  concrete  slab,  footings,  and
               structural  beams of the roof, in each case necessary to preserve
               the load bearing capacity thereof.  Landlord shall in no event be
               responsible to Tenant for the repair of glass (including exterior
               glass,  the doors (or  related  glass and  finish  work)  into or
               inside the  Building),  or any  condition  in the Premises or the
               Building caused by any act or neglect of Tenant,  its invitees or
               contractors.  Landlord shall in no event be  responsible  for any
               maintenance  or  repairs  required  by reason of any  Alterations
               performed by or on behalf of Tenant. Landlord shall also keep and
               maintain  those  exterior  portions of the Premises which are not
               specifically the obligation of Tenant as set forth in Section 7.2
               herein, in a good and clean order,  condition and repair, free of
               snow and ice, and shall keep and maintain all landscaped areas in
               the  exterior  portions  of the  Premises  in a neat and  orderly
               condition (collectively, the "Exterior Work"); provided, however,
               that Tenant may elect to perform the  Exterior  Work  required in
               this sentence  upon sixty (60) days notice to Landlord  whereupon
               the management fee described in Exhibit D hereto shall be reduced
               as described in said Exhibit D.  Landlord  agrees that,  prior to
               the Commencement Date, it shall, at its own expense, sealcoat and
               restripe  the  parking  area  at  the  Premises  in  its  current
               configuration  and  clean and trim the  landscaping  on the Land.
               Landlord  shall not be responsible  to make any  improvements  or
               repairs to the  Premises  other than as expressly in this Section
               7.1 provided, unless expressly provided.

                                       12
<PAGE>

          (b)  Landlord  shall never be liable for any  failure to make  repairs
               which  Landlord has  undertaken  to make under the  provisions of
               this Section 7.1 or elsewhere  in this Lease,  unless  Tenant has
               given  notice to Landlord of the need to make such  repairs,  and
               Landlord  has failed to  commence to make such  repairs  within a
               reasonable time after receipt of such notice, or fails to proceed
               with reasonable diligence to complete such repairs.

          (c)  Tenant shall have certain  self-help  rights  pursuant to Section
               14.10 hereof.

7.2  TENANT REPAIRS.

          (a)  Except as otherwise provided in this Lease, Tenant agrees to keep
               in good order,  condition and repair  (including  replacement of)
               each  and  every  part  of  the   Premises,   including   without
               limitation,  exterior walls (including  exterior window units and
               glass), the roof (excluding the structural beams thereof) and all
               life safety, HVAC,  plumbing,  mechanical and electrical systems,
               excepting  only  reasonable  wear and tear of the  Premises;  and
               Tenant shall  surrender  the Premises to Landlord,  at the end of
               the Term, in such condition.  Without  limitation,  except as set
               forth in Section 7.2(b) below, Tenant shall comply with all laws,
               codes  and  ordinances  from  time  to  time  in  effect  and all
               directions, rules and regulations of governmental agencies having
               jurisdiction, and the standards recommended by the local Board of
               Fire Underwriters applicable to Tenant's use and occupancy of the
               Premises,  and shall,  at  Tenant's  expense,  timely  obtain all
               permits, licenses and the like required thereby.

               Notwithstanding  the  foregoing  or any other  provision  of this
               Lease to the contrary,  however,  Tenant shall not be responsible
               to conduct the work necessary for compliance (the "New Law Work")
               with any new laws,  regulations,  or  standards  which are not in
               effect on the date of this Lease (the "New Laws"), which New Laws
               require  (i) repairs or  modifications  to the  Structure  of the
               Building,  or (ii)  repairs or  modifications  to the  utility or
               Building service equipment, or (iii) installation of new Building
               service   equipment,   such  as  fire  detection  or  suppression
               equipment, unless such repairs,  modifications,  or installations
               shall  (a) be due to  Tenant's  particular  manner  of use of the
               Premises (as opposed to office and research and  development  use
               generally), (b) be due to the negligence or willful misconduct of
               Tenant or  Tenant's  Agents,  or (c) be due to  Tenant's  Work or
               Tenant's  Alterations..  Subject to Section 10.5 regarding waiver
               of  subrogation,  Tenant  shall  be  responsible  for the cost of
               repairs  which may be made  necessary  by reason of damage to the
               Building  caused by any act or  neglect  of  Tenant  or  Tenant's
               Agents  (including any damage by fire or other  casualty  arising
               therefrom).

          (b)  If repairs  are  required  to be made by Tenant  pursuant  to the
               terms hereof, and Tenant fails to make the repairs, upon not less
               than twenty (20) days' prior written notice from Landlord stating
               Landlord's  intention  to use  self-help  (except  that no notice
               shall be required  in the event of an  emergency),  Landlord  may
               make or cause such  repairs to be made (but shall not be required
               to do so), and the provisions of Section 14.4 shall be applicable
               to the costs thereof. Landlord shall not be responsible to Tenant
               for any loss or damage  whatsoever  that may  accrue to  Tenant's
               stock or business by reason of  Landlord's  making such  repairs,
               but   Landlord   shall  use   reasonable   efforts  to   minimize
               interference with Tenant's use of the Premises.

          (c)  Notwithstanding   any  provision  herein  to  the  contrary,   if
               replacements  or repairs of a capital  nature for which Tenant is
               responsible  are  necessary  based upon the mutual  agreement  of
               Landlord and Tenant using their reasonable  discretion during the
               last  two (2)  years  of the  Term as the  same  may be  extended
               pursuant hereto, such replacements shall be made by Landlord, and
               Tenant's  obligation  with respect  thereto shall be to reimburse
               Landlord based upon the annual  charge-off set forth in Paragraph
               6 of Exhibit D hereto.

7.3  FLOOR LOAD - HEAVY MACHINERY.

          (a)  Tenant  shall not  place a load  upon any  floor in the  Premises
               exceeding the floor load per square foot of area which such floor
               was  designed  to carry and  which is  allowed  by law.  Landlord
               reserves  the right to  prescribe  the weight and position of all
               business  machines and  mechanical  equipment,  including  safes,
               which shall be placed so as to  distribute  the weight.  Business
               machines and mechanical  equipment shall be placed and maintained
               by  Tenant  at  Tenant's  expense  in  settings  sufficient,   in
               Landlord's judgment,  to absorb and prevent vibration,  noise and
               annoyance. Tenant shall not move any safe, heavy machinery, heavy
               equipment,  freight,  bulky matter or fixtures into or out of the
               Building  without  Landlord's  prior  consent,  which consent may
               include a requirement to provide insurance, naming Landlord as an
               insured, in such amounts as Landlord may deem reasonable.

                                       13
<PAGE>

          (b)  If any such safe, machinery,  equipment, freight, bulky matter or
               fixtures requires special handling,  Tenant agrees to employ only
               persons  holding a Master  Rigger's  License to do such work, and
               that  all  work  in  connection   therewith   shall  comply  with
               applicable laws and regulations.  Any such moving shall be at the
               sole risk and  hazard  of  Tenant,  and  Tenant  will  exonerate,
               indemnify  and  save  Landlord  harmless  against  and  from  any
               liability,  loss,  injury,  claim or suit  resulting  directly or
               indirectly from such moving.

7.4  ELECTRICITY   SERVICE.   The  Premises  shall  be  separately  metered  for
     electricity  such that the applicable  public  utility  company can provide
     electricity  directly to the Premises,  and Tenant shall be responsible for
     payment of all  electricity  charges  directly to such  utility  (including
     electricity for all lighting, heating,  ventilation and air conditioning in
     the Premises.)  Landlord shall permit  Landlord's  existing wires,  risers,
     conduits and other electrical equipment to be used to supply electricity to
     Tenant at the  Premises,  and Tenant agrees in its use of the Premises that
     its total connected  lighting load will not exceed the maximum from time to
     time permitted under applicable  governmental  regulations.  If, without in
     any way  derogating  from the  foregoing  limitation,  Tenant shall require
     electricity in excess of the requirements set forth above,  provided Tenant
     first obtains  Landlord's  consent (which Landlord may withhold in its sole
     discretion),   Tenant  may  perform  the  work  necessary  to  supply  such
     additional  service or  equipment,  at  Tenant's  sole cost and expense and
     subject to the requirements of Section 5.2 of this Lease.

7.5  INTERRUPTION  OF SERVICE.  Landlord  shall not be responsible in any manner
     for  any  suspension,  interruption  or  curtailment  of  any  services  or
     utilities  to the  Premises (an  "Interruption"),  regardless  of the cause
     thereof,  and no such  suspension,  interruption or curtailment  shall give
     rise to any claim for  abatement  of rent or other  compensation  to Tenant
     from Landlord, nor shall Tenant claim any direct, indirect or consequential
     damages or constructive  eviction on account thereof,  nor shall this Lease
     or any obligation of Tenant be affected thereby.

     Notwithstanding  the  foregoing,  if  Tenant  shall  give  Landlord  notice
     ("Abatement  Notice") of any Abatement Event, as defined below, and if such
     Abatement Event continues beyond the "Eligibility  Period" (as that term is
     defined below), then the Basic Rent and Tenant's other monetary obligations
     to Landlord shall be abated entirely or reduced,  as the case may be, after
     expiration of the Eligibility Period for such time that Tenant continues to
     be so  prevented  from using,  and does not use,  the Premises or a portion
     thereof,  in the  proportion  that the rentable  area of the portion of the
     Premises that Tenant is prevented  from using,  and does not use,  bears to
     the total rentable area of the Premises;  provided,  however,  in the event
     that Tenant is  prevented  from  using,  and does not use, a portion of the
     Premises for a period of time in excess of the  Eligibility  Period and the
     remaining  portion of the  Premises is not  sufficient  to allow  Tenant to
     effectively  conduct its business  therein,  and if Tenant does not conduct
     its  business  from  such  remaining  portion,  then  for such  time  after
     expiration  of the  Eligibility  Period during which Tenant is so prevented
     from effectively  conducting its business therein,  Basic Rent and Tenant's
     other monetary  obligations  to Landlord shall be abated  entirely for such
     time as Tenant  continues to be so prevented from using,  and does not use,
     the  Premises.  An  "Abatement  Event" shall be defined as an  Interruption
     (other than those  addressed in Article XI) that prevents Tenant from using
     the Premises or any material portion thereof. The term "Eligibility Period"
     shall mean a period of ten (10) consecutive  days after Landlord's  receipt
     of any  Abatement  Notice(s).  The  provisions  of this  Section  7.5 shall
     constitute the sole right and remedy of Tenant with respect to an Abatement
     Event

                                       14
<PAGE>

                                   ARTICLE 8

                                REAL ESTATE TAXES

8.1  PAYMENTS ON ACCOUNT OF REAL ESTATE TAXES.

          (a)  "Tax Year" shall mean a twelve-month  period commencing on July 1
               and  falling  wholly or  partially  within the Term,  and "Taxes"
               shall mean (i) all taxes,  assessments  (special  or  otherwise),
               levies,  fees and all  other  government  levies,  exactions  and
               charges of every kind and nature,  general and special,  ordinary
               and  extraordinary,  foreseen and  unforeseen,  which are, at any
               time  prior to or during  the  Term,  imposed  or levied  upon or
               assessed against the Property or any portion thereof,  or against
               any  Basic  Rent,  Additional  Rent or other  rent of any kind or
               nature payable to Landlord by anyone on account of the ownership,
               leasing or operation of the  Property,  or which arise on account
               of  or  in  respect  of  the  ownership,   development,  leasing,
               operation or use of the Property or any portion thereof; (ii) all
               gross  receipts  taxes or similar  taxes  imposed or levied upon,
               assessed against or measured by any Base Rent, Additional Rent or
               other rent of any kind or nature or other sum payable to Landlord
               by anyone on  account  of the  ownership,  development,  leasing,
               operation,  or use of the Property or any portion thereof;  (iii)
               all  value  added,  use and  similar  taxes at any  time  levied,
               assessed  or payable on  account of the  ownership,  development,
               leasing,  operation,  or  use  of the  Property  or  any  portion
               thereof;  and (iv)  reasonable  expenses  of any  proceeding  for
               abatement  of any of  the  foregoing  items  included  in  Taxes,
               provided Landlord prevails in such abatement proceeding;  but the
               amount of special taxes or special assessments  included in Taxes
               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 Taxes all  income,  estate,  succession,
               inheritance  and transfer taxes of Landlord;  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 a
               capital levy, franchise,  income, profits, sales, rental, use and
               occupancy,  excise or other  tax or  charge  shall in whole or in
               part be  substituted  for,  or added to,  such ad valorem tax and
               levied  against,  or be payable by,  Landlord with respect to the
               Property  or any  portion  thereof,  such tax or charge  shall be
               included in the term  "Taxes" for the  purposes of this  Article.
               There shall also be excluded from Taxes any  so-called  "linkage"
               fees  related to  obligations  of the  original  developer of the
               Building  to  provide  off-site   improvements  such  as  roadway
               improvements and the like.

          (b)  Tenant shall pay to Landlord, as Additional Rent, an amount equal
               to the amount of Taxes attributable to each Tax Year, such amount
               to be  apportioned  for any  portion  of a Tax Year in which  the
               Commencement Date falls or the Term expires.

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

8.2  ABATEMENT.  If Landlord  shall receive any tax refund or  reimbursement  of
     Taxes  or sum in lieu  thereof  with  respect  to any Tax  Year  all or any
     portion of which falls within the Term,  then out of any balance  remaining
     thereof  after  deducting  Landlord's  actual  expenses in  obtaining  such
     refund,  Landlord shall pay to Tenant, provided there does not then exist a
     Default of Tenant,  an amount equal to such refund or  reimbursement or sum
     in lieu thereof (exclusive of any interest,  and apportioned if such refund
     is for a Tax Year a portion of which falls  outside the Term)  Tenant shall
     have the right,  upon written  notice to Landlord,  to seek an abatement of
     Taxes or sum in lieu thereof with respect to any Tax Year, all or a portion
     of which falls within the Term,  and Landlord  shall  reasonably  cooperate
     with  such  proceeding.  If  Tenant  does not seek an  abatement  for a Tax
     Year(s)  during the Term,  Landlord  may file for an abatement  if,  within
     fifteen (15) days after providing  Tenant with written notice of Landlord's
     intent to so file,  Tenant  does not file for such  abatement  and  provide
     Landlord with written notice thereof, and Tenant shall cooperate reasonably
     with Landlord in connection with any such proceeding.  Notwithstanding  the
     foregoing,  in no event shall  Tenant be entitled to receive  more than the
     payments  made by  Tenant on  account  of Taxes for any such Tax Year or to
     receive any payments or abatement of Basic Rent.

                                       15
<PAGE>

                                   ARTICLE 9

                         OPERATING AND UTILITY EXPENSES

9.1  DEFINITIONS. "Operating Year" shall mean each calendar year all or any part
     of which falls within the Term,  and  "Operating  Expenses"  shall mean the
     aggregate  reasonable costs and expenses  incurred by Landlord with respect
     to  the   operation,   administration,   cleaning,   repair,   replacement,
     maintenance and management of the Property and all portions thereof, all as
     set forth in Exhibit D attached hereto.

9.2  TENANT'S PAYMENT OF OPERATING EXPENSES.

          (a)  Tenant shall pay to Landlord, as Additional Rent, an amount equal
               to the Operating  Expenses  attributable  to each Operating Year,
               such amount to be  apportioned  for any  portion of an  Operating
               Year in which  the  Commencement  Date  falls or the Term of this
               Lease ends.

          (b)  Estimated  payments  by Tenant on account of  Operating  Expenses
               shall be made on the first day of each and every  calendar  month
               during the Term of this Lease, in the fashion herein provided for
               the  payment of Basic Rent.  The monthly  amount so to be paid to
               Landlord  shall be sufficient  to provide  Landlord by the end of
               each Operating Year a sum equal to Tenant's required payment,  as
               reasonably  estimated  by Landlord  from time to time during each
               Operating  Year,  on  account  of  Operating  Expenses  for  such
               Operating Year.  After the end of each Operating  Year,  Landlord
               shall  submit  to  Tenant a  reasonably  detailed  accounting  of
               Operating  Expenses for such  Operating  Year, and Landlord shall
               certify  to  the  accuracy   thereof.   If   estimated   payments
               theretofore  made  for  such  Operating  Year  by  Tenant  exceed
               Tenant's  required  payment on account thereof for such Operating
               Year  according  to such  statement,  Landlord  shall  credit the
               amount of overpayment  against  subsequent  obligations of Tenant
               with  respect to  Operating  Expenses  (or  promptly  refund such
               overpayment if the Term of this Lease has ended and Tenant has no
               further obligation to Landlord);  but if the required payments on
               account  thereof for such  Operating  Year are  greater  than the
               estimated  payments (if any)  theretofore made on account thereof
               for such  Operating  Year,  Tenant shall make payment to Landlord
               within  thirty (30) days after being so advised by Landlord,  and
               the  obligation  to make such  payment for any period  within the
               Term shall survive expiration of the Term.

          (c)  Notwithstanding  any  provision  of this Section 9.2 or any other
               provision  of this Lease to the  contrary,  Tenant shall also pay
               certain  Operating  Expenses for the period beginning on Tenant's
               early entry as described in Section 4.3.

          (d)  Tenant shall pay, directly to the proper authorities charged with
               collection  thereof,  all charges for utilities used and consumed
               in the Premises,  including without limitation,  charges for gas,
               electricity  and  telephone  service;  provided,   however,  that
               Landlord  shall  pay water and  sewer  charges  for the  Premises
               directly to the service  provider  and  include  such  charges in
               Operating Expenses.

9.3  TENANT'S  AUDIT  RIGHT.  Tenant  shall have the right to examine,  copy and
     audit Landlord's books and records establishing  Operating Expenses for any
     Operating  Year for a period of one (1) year following the date that Tenant
     receives the statement of Operating  Expenses for such  Operating Year from
     Landlord.  Tenant shall give Landlord not less than thirty (30) days' prior
     notice of its  intention to examine and audit such books and  records,  and
     such  examination  and audit  shall  take  place at such  place  within the
     continental  United States as Landlord  routinely  maintains such books and
     records,  unless  Landlord  elects to have such  examination and audit take
     place in another  location  designated by Landlord in the city and state in
     which the Property is located. All costs of the examination and audit shall
     be borne by Tenant;  provided,  however, that if such examination and audit
     establishes  that the actual  Operating  Expenses for the Operating Year in
     question  are less  than the  amount  set  forth  as the  annual  Operating
     Expenses  on the  annual  statement  delivered  to Tenant by at least  five
     percent  (5%),  then  Landlord  shall  pay  the  reasonable  costs  of such
     examination  and audit.  If,  pursuant to the audit,  the payments made for
     such Operating Year by Tenant exceed Tenant's  required  payment on account
     thereof  for such  Operating  Year,  Landlord  shall  credit  the amount of
     overpayment  against  subsequent  obligations  of Tenant  with  respect  to
     Operating Expenses (or promptly refund such overpayment if the Term of this
     Lease has ended and Tenant has no further obligation to Landlord);  but, if
     the payments made by Tenant for such  Operating Year are less than Tenant's
     required payment as established by the examination and audit,  Tenant shall
     pay the deficiency to Landlord within thirty (30) days after  conclusion of
     the examination and audit,  and the obligation to make such payment for any
     period within the Term shall survive expiration of the Term. If Tenant does
     not elect to exercise its right to examine and audit  Landlord's  books and
     records for any Operating Year within the time period  provided for by this
     paragraph,  Tenant  shall have no  further  right to  challenge  Landlord's
     statement of Operating Expenses.

                                       16
<PAGE>

                                   ARTICLE 10

                    INDEMNITY AND PUBLIC LIABILITY INSURANCE

10.1 TENANT'S  INDEMNITY.  Except to the extent  arising from the  negligence or
     willful misconduct of Landlord or its agents or employees, Tenant agrees to
     indemnify and save harmless Landlord and Landlord's Agents from and against
     all claims,  losses,  costs,  damages,  liabilities or expenses of whatever
     nature arising:  (i) from any accident,  injury or damage whatsoever to any
     person,  or to the  property  of any  person,  occurring  in or  about  the
     Premises;  or (ii)  from the use or  occupancy  of the  Premises  or of any
     business  conducted  therein,   and,  in  any  case,  occurring  after  the
     Commencement  Date  until  the  expiration  of the Term of this  Lease  and
     thereafter  so long as Tenant is in occupancy of any part of the  Premises;
     or (iii)  directly from any default or breach by Tenant or Tenant's  Agents
     under  the  terms or  covenants  of this  Lease.  This  indemnity  and hold
     harmless  agreement  shall  include  indemnity  against all losses,  costs,
     damages,  expenses and  liabilities  incurred in or in connection  with any
     such claim or any  proceeding  brought  thereon,  and the defense  thereof,
     including, without limitation, reasonable attorneys' fees and costs at both
     the trial and appellate levels.

10.2 TENANT  INSURANCE.  Tenant  agrees to  maintain in full force from the date
     upon which Tenant first enters the Premises for any reason,  throughout the
     Term of this Lease, and thereafter so long as Tenant is in occupancy of any
     part of the Premises, a policy of commercial general liability and property
     damage insurance (including broad form contractual  liability,  independent
     contractor's hazard and completed  operations  coverage) under which Tenant
     is named as an insured and  Landlord,  Agent (and such other persons as are
     in privity of estate with  Landlord as may be set out in a notice from time
     to time) are named as  additional  insureds,  and under  which the  insurer
     agrees to indemnify and hold Landlord, Agent and those in privity of estate
     with Landlord, harmless from and against all cost, expense and/or liability
     arising out of or based upon any and all claims,  accidents,  injuries  and
     damages  set forth in Section  10.1.  Tenant  may  satisfy  such  insurance
     requirements  by  including  the Premises in a so-called  "blanket"  and/or
     "umbrella" insurance policy, provided that the amount of coverage allocated
     to the Premises  shall  fulfill the  requirements  set forth  herein.  Each
     policy required  hereunder shall be non-cancelable  and non-amendable  with
     respect to Landlord,  Agent and Landlord's  said  designees  without thirty
     (30) days' prior notice,  shall be written on an  "occurrence"  basis,  and
     shall be in at least the amounts of the Initial General Liability Insurance
     specified  in  Section  1.1 or such  greater  amounts  as  Landlord  in its
     reasonable  discretion  shall from time to time  request,  and a  duplicate
     original or certificates thereof satisfactory to Landlord,  together with a
     photocopy of the entire policy, shall be delivered to Landlord.

10.3 TENANT'S RISK. Tenant agrees to use and occupy the Premises at Tenant's own
     risk.  Landlord  shall not be liable to Tenant or  Tenant's  Agents for any
     damage, injury, loss,  compensation,  or claim (including,  but not limited
     to, claims for the interruption of or loss to Tenant's  business) based on,
     arising out of or resulting from any cause whatsoever,  including,  but not
     limited to,  repairs to any portion of the  Premises or the  Property,  any
     fire, robbery,  theft,  mysterious  disappearance and/or any other crime or
     casualty,  the actions of any person or persons, or any leakage in any part
     or portion of the  Premises or the  Building,  or from water,  rain or snow
     that may leak into,  or flow from any part of the Premises or the Building,
     or from drains,  pipes or plumbing fixtures in the Building,  unless due to
     the  negligence or willful  misconduct  of Landlord or  Landlord's  agents,
     contractors or employees. Any goods, property or personal effects stored or
     placed in or about the  Premises  shall be at the sole risk of Tenant,  and
     neither  Landlord  nor  Landlord's  insurers  shall in any  manner  be held
     responsible therefor.  Notwithstanding the foregoing, Landlord shall not be
     released from liability for any injury,  loss,  damages or liability to the
     extent arising from any negligence or willful  misconduct of Landlord,  its
     servants, employees or agents acting within the scope of their authority on
     or about the Premises;  provided, however, that in no event shall Landlord,
     its servants, employees or agents have any liability to Tenant based on any
     loss with respect to or interruption in the operation of Tenant's business,
     except for  potential  abatement  to the  extent set forth in Section  7.5.
     Tenant shall carry "all-risk"  property  insurance on a "replacement  cost"
     basis,  insuring  Tenant's  Removable  Property and any Alterations made by
     Tenant pursuant to Section 5.2, to the extent that the same have not become
     the property of Landlord.

10.4 LANDLORD'S  INDEMNITY.  Except to the extent arising from the negligence or
     willful  misconduct  of  Tenant  or  Tenant's  Agents,  Landlord  agrees to
     indemnify and save harmless Tenant and Tenant's Agents from and against all
     claims, losses, costs, damages,  liabilities or expenses of whatever nature
     arising: (i) from any accident,  injury or damage whatsoever to any person,
     or to the property of any person, occurring in or about the Premises to the
     extent such  accident,  injury or damage  results  from any  negligence  or
     willful  misconduct on the part of Landlord or Landlord's  Agents;  or (ii)
     directly from any default or breach by Landlord or Landlord's  Agents under
     any terms or  covenants of this Lease.  This  indemnity  and hold  harmless
     agreement  shall  include  indemnity  against all losses,  costs,  damages,
     expenses and  liabilities  incurred in or in connection with any such claim
     or any proceeding  brought  thereon,  and the defense  thereof,  including,
     without limitation,  reasonable attorneys' fees and costs at both the trial
     and appellate levels.

10.5 WAIVER OF SUBROGATION. The parties hereto shall each procure an appropriate
     clause in, or endorsement on, any property insurance policy on the Premises
     or any personal property, fixtures or equipment located thereon or therein,
     pursuant to which the insurer waives subrogation or consents to a waiver of
     right of  recovery  in favor of  either  party,  its  respective  agents or
     employees.  Having  obtained such clauses and/or  endorsements,  each party
     hereby  agrees  that it will not make any claim  against or seek to recover
     from the  other or its  agents or  employees  for any loss or damage to its
     property or the  property  of others  resulting  from fire or other  perils
     covered by such property insurance.

                                       17
<PAGE>

                                   ARTICLE 11

                           FIRE, EMINENT DOMAIN, ETC.

11.1 LANDLORD'S  RIGHT OF  TERMINATION.  If (a) the  Building  is  substantially
     damaged  by fire or  casualty  (the term  "substantially  damaged"  meaning
     damage of such a character  that the same cannot,  in the ordinary  course,
     reasonably be expected to be repaired within two hundred seventy (270) days
     from the time that repair work would  commence) or (b) if any material part
     of the  Premises is taken by any  exercise  of the right of eminent  domain
     thereby rendering the Premises unusable for Tenant's purposes, then each of
     Tenant and Landlord  shall have the right to terminate  this Lease (even if
     Landlord's  entire  interest in the  Premises  may have been  divested)  by
     giving notice to the other of its election so to do within thirty (30) days
     after the occurrence of such casualty or the effective date of such taking,
     whereupon  this Lease  shall  terminate  thirty (30) days after 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.

11.2 RESTORATION.  Tenant's Right of Termination. If (a) the Building is damaged
     by fire or  other  casualty  or (b)  part of the  Premises  is taken by any
     exercise of the right of eminent domain but such taking does not render the
     Premises unusable for Tenant's  purposes,  and this Lease is not terminated
     pursuant to Section 12.1,  Landlord shall thereafter use reasonable efforts
     to restore  the  Building  (excluding  any  Alterations  made by Tenant but
     including  restoration  of Tenant's Work,  exclusive of Tenant's  Removable
     Property,  but  only to the  extent  the  same are  covered  by  Landlord's
     property  damage  insurance  required  pursuant to Section  11.3 herein) to
     proper condition for Tenant's use and occupation,  provided that Landlord's
     obligation  shall be limited to the amount of insurance and eminent  domain
     proceeds available therefor. If, for any reason, such restoration shall not
     be substantially  completed within two hundred seventy (270) days after the
     expiration  of  the  30-day  period  referred  to in  Section  11.1  (which
     six-month  period may be extended  for such  periods of time as Landlord is
     prevented from proceeding with or completing such  restoration due to Force
     Majeure, but in no event for more than an additional three months),  Tenant
     shall have the right to terminate  this Lease by giving  notice to Landlord
     within  thirty  (30)  days  after  the  expiration  of such  period  (as so
     extended)  provided  that such  restoration  is not  completed  within such
     period. This Lease shall cease and come to an end without further liability
     or  obligation  on the part of either  party  thirty  (30) days  after such
     giving  of  notice  unless,   within  such  thirty-day   period,   Landlord
     substantially  completes such restoration.  Such right of termination shall
     be Tenant's  sole and exclusive  remedy at law or in equity for  Landlord's
     failure so to complete such  restoration,  and time shall be of the essence
     with respect thereto.

11.3 LANDLORD'S INSURANCE. Landlord agrees to maintain in full force and effect,
     during  the  Term  of  this  Lease,  property  damage  insurance  for  full
     replacement cost of the Building (excluding footings and foundations), with
     such deductibles as may from time to time be carried by reasonably  prudent
     owners of similar  buildings  in the area in which the Property is located.
     Landlord may satisfy such insurance  requirements by including the Property
     in a so-called  "blanket"  insurance  policy,  provided  that the amount of
     coverage   allocated  to  the   Property   shall   fulfill  the   foregoing
     requirements.

11.4 ABATEMENT OF RENT.  If the  Building is damaged by fire or other  casualty,
     Basic   Rent  and   Additional   Rent   payable  by  Tenant   shall   abate
     proportionately  for the period  during  which,  by reason of such  damage,
     there is material  interference  with Tenant's use of the Building,  having
     regard  for the  extent to which  Tenant  may be  required  to  discontinue
     Tenant's  use of all or an  undamaged  portion of the  Building due to such
     damage,  but such  abatement  or reduction  shall end if and when  Landlord
     shall have substantially  completed  sufficient  restoration that Tenant is
     able to use the Building without material  interference and the Building is
     in  substantially  the condition it was in prior to such damage  (excluding
     any  Alterations  made by Tenant  pursuant to Section 5.2). If the Premises
     shall be affected by any  exercise  of the power of eminent  domain,  Basic
     Rent and  Additional  Rent payable by Tenant shall be justly and  equitably
     abated and  reduced  according  to the nature and extent of the loss of use
     thereof  suffered by Tenant.  In no event shall Landlord have any liability
     for damages to Tenant for  inconvenience,  annoyance,  or  interruption  of
     business arising from any fire or other casualty or eminent domain.

11.5 CONDEMNATION  AWARD.  Landlord shall have and hereby  reserves and excepts,
     and Tenant hereby grants and assigns to Landlord, all rights to recover for
     damages to the Property and the leasehold  interest hereby created,  and to
     compensation  accrued or  hereafter  to accrue by reason of any taking,  by
     exercise  of the right of  eminent  domain,  and by way of  confirming  the
     foregoing, Tenant hereby grants and assigns, and covenants with Landlord to
     grant and assign to Landlord,  all rights to such damages or  compensation,
     and covenants to deliver such further assignments and assurances thereof as
     Landlord may from time to time request.  Nothing  contained herein shall be
     construed to prevent  Tenant from  prosecuting  in a separate  condemnation
     proceeding  a claim for the  value of any of  Tenant's  Removable  Property
     installed in the Premises by Tenant at Tenant's  expense and for relocation
     expenses.

                                       18
<PAGE>

                                   ARTICLE 12

                             HOLDING OVER; SURRENDER

12.1 HOLDING OVER.  Any holding over by Tenant after the  expiration of the Term
     of this Lease shall be treated as a daily  tenancy at  sufferance at a rent
     equal to two (2) times the Basic  Rent then in effect  plus the  Additional
     Rent herein provided (prorated on a daily basis).  After the first month of
     any such  holding  over,  Tenant  shall also pay to Landlord  all  damages,
     direct  and/or  indirect,  sustained by reason of any such holding over. In
     all other respects,  such holding over shall be on the terms and conditions
     set forth in this Lease as far as applicable.

12.2 SURRENDER OF PREMISES.  Upon the  expiration or earlier  termination of the
     Term of this Lease,  Tenant shall  peaceably quit and surrender to Landlord
     the Premises in neat and clean  condition and in good order,  condition and
     repair, together with all alterations, additions and improvements which may
     have been made or installed  in, on or to the  Premises  prior to or during
     the Term of this Lease (except as  hereinafter  provided),  excepting  only
     ordinary wear and use and damage by fire or other casualty for which, under
     other provisions of this Lease,  Tenant has no  responsibility to repair or
     restore. Tenant shall remove all of Tenant's Removable Property and may, at
     its  election,  remove or leave in place (a) the  fifty  (50)  workstations
     currently located in the Building (which workstations shall become Tenant's
     personal  property  one (1) year from the date  hereof so long as Tenant is
     not then in  default  hereunder  and this  Lease is then in full  force and
     effect and which  workstations  shall become  Landlord's  personal property
     upon the  expiration or earlier  termination  of the Term if Tenant chooses
     not to remove the same as  aforesaid),  and;  (b) all  Alterations  made by
     Tenant at Tenant's expense. Tenant shall repair any damages to the Premises
     or the Building caused by any such removal.  Any of (1) said  workstations,
     (2)  Tenant's  Removable  Property,  and (3) such  Alterations  which shall
     remain  in  the  Building  or on  the  Premises  after  the  expiration  or
     termination of the Term of this Lease shall be deemed  conclusively to have
     been  abandoned,  and either may be retained by Landlord as its property or
     may be disposed of in such  manner as  Landlord  may see fit at  Landlord's
     sole cost and expense,  except with respect to Tenant's  Removable Property
     which shall be at Tenant's sole cost and expense.

                                   ARTICLE 13

                     RIGHTS OF MORTGAGEES; TRANSFER OF TITLE

13.1 RIGHTS OF MORTGAGEES. Provided Tenant receives a fully-executed original of
     the SNDA, or a similar  instrument  reasonably  acceptable to Tenant,  this
     Lease  shall be  subject  and  subordinate  to the  lien  and  terms of any
     mortgage,   deed  of  trust  or  ground   lease  or   similar   encumbrance
     (collectively,  a "Mortgage",  and the holder thereof from time to time the
     "Holder") from time to time encumbering the Premises,  whether executed and
     delivered  prior to or  subsequent  to the date of this  Lease,  unless the
     Holder shall elect otherwise.  If this Lease is subordinate to any Mortgage
     and the Holder or any other party shall succeed to the interest of Landlord
     pursuant to the Mortgage  (such Holder or other party, a  "Successor"),  at
     the election of the Holder or Successor,  Tenant shall attorn to the Holder
     or Successor and this Lease shall continue in full force and effect between
     the  Holder  or  Successor  and  Tenant.  Tenant  agrees  to  execute  such
     instruments of subordination or attornment in confirmation of the foregoing
     agreement as the Holder or Successor  reasonably may request.  With respect
     to each  Mortgage  encumbering  the  Premises  from time to time during the
     Term, Landlord and Tenant agree to execute a subordination, non-disturbance
     and attornment agreement ("SNDA") in substantially the form attached hereto
     as Exhibit G, and  Landlord  shall cause the current  Holder of the current
     Mortgage,  and make  reasonable  efforts to cause any future  Holder of any
     future  Mortgage,  to execute same,  whereupon  Landlord shall deliver such
     executed SNDA to Tenant.

13.2 ASSIGNMENT OF RENTS AND TRANSFER OF TITLE.

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

          (b)  In no event shall the  acquisition of Landlord's  interest in the
               Property by a purchaser which,  simultaneously therewith,  leases
               Landlord's  entire  interest in the  Property  back to the seller
               thereof  be  treated  as an  assumption  by  operation  of law or
               otherwise, of Landlord's obligations hereunder,  but Tenant shall
               look solely to such  seller-lessee,  and its successors from time
               to time in  title,  for  performance  of  Landlord's  obligations
               hereunder.  In any such  event,  this Lease  shall be subject and
               subordinate  to the lease to such  purchaser.  For all  purposes,
               such  seller-lessee,  and its  successors in title,  shall be the
               Landlord  hereunder  unless and until  Landlord's  position shall
               have been assumed by such purchaser-lessor.

          (c)  Except as provided in paragraph (b) of this Section, in the event
               of any transfer of title to the  Property by  Landlord,  Landlord
               shall   thereafter  be  entirely  freed  and  relieved  from  the
               performance  and  observance  of all  covenants  and  obligations
               hereunder.

                                       19
<PAGE>

13.3 NOTICE TO MORTGAGEE.  After receiving notice from Landlord of any Holder of
     a Mortgage which  includes the Premises,  no notice from Tenant to Landlord
     alleging any default by Landlord shall be effective unless and until a copy
     of the  same is given to such  Holder  (provided  Tenant  shall  have  been
     furnished with the name and address of such Holder),  and the curing of any
     of Landlord's  defaults by such Holder shall be treated as  performance  by
     Landlord.

                                   ARTICLE 14

                                DEFAULT; REMEDIES

14.1 TENANT'S DEFAULT.

          (a)  If at any time  subsequent  to the date of this  Lease any one or
               more of the following events (herein referred to as a "Default of
               Tenant") shall happen:

          (i)  Tenant  shall fail to pay the Basic Rent or any other  Additional
               Rent  hereunder when due and such failure shall continue for five
               (5) Business Days after notice to Tenant from Landlord; or

          (ii) Tenant  shall  neglect or fail to  perform  or observe  any other
               covenant  herein  contained  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  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 (and in any event
               within  such  thirty  (30) day  period) to remedy the same and to
               prosecute such remedy to completion with diligence and continuity
               (and in any  event,  within  ninety  (90) days  after the  notice
               described in this subparagraph (ii)); or

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

          (iv) Tenant shall make an  assignment  for the benefit of creditors or
               shall be  adjudicated  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 (other than
               the Bankruptcy  Code, as hereinafter  defined),  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

          (v)  An Event of Bankruptcy (as hereinafter  defined) shall occur with
               respect to Tenant; or

          (vi) A petition  shall be filed  against  Tenant  under any law (other
               than   the   Bankruptcy   Code)   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  trustee,  conservator,   receiver  or
               liquidator  of  Tenant or of all or any  substantial  part of its
               properties 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);

          (vii)If:  (x)  Tenant  shall  fail  to  pay  the  Basic  Rent  or  any
               Additional  Rent  hereunder  when due or shall fail to perform or
               observe any other covenant  herein  contained on Tenant's part to
               be  performed  or observed and Tenant shall cure any such failure
               within the  applicable  grace  period set forth in clauses (i) or
               (ii)  above;  or (y) a Default of Tenant of the kind set forth in
               clauses (i) or (ii) above shall occur and Landlord  shall, in its
               sole  discretion,  permit  Tenant to cure such  Default of Tenant
               after the applicable grace period has expired;  and the same or a
               similar  failure  shall  occur more than once within the next 365
               days  (whether or not such  similar  failure is cured  within the
               applicable grace period); or

          (viii) The  occurrence  of any of the events  described in  paragraphs
               (a)(iv)-(a)(vi)  with  respect  to  any  guarantor  of all or any
               portions of Tenant's  obligations  under this Lease;  then in any
               such  case  Landlord  may  terminate  this  Lease as  hereinafter
               provided.

          (b)  For purposes of clause  (a)(v)  above,  an "Event of  Bankruptcy"
               means the filing of a voluntary  petition by Tenant, or the entry
               of an order for relief against Tenant, under Chapter 7, 11, or 13
               of the Bankruptcy Code, and the term  "Bankruptcy  Code" means 11
               U.S.C ss.101, et seq.. If an Event of Bankruptcy occurs, then the
               trustee   of   Tenant's    bankruptcy   estate   or   Tenant   as
               debtor-in-possession may (subject to final approval of the court)
               assume this  Lease,  and may  subsequently  assign it, only if it
               does the  following  within sixty (60) days after the date of the
               filing  of the  voluntary  petition,  the  entry of the order for
               relief  (or  such   additional  time  as  a  court  of  competent
               jurisdiction may grant, for cause,  upon a motion made within the
               original sixty-day period):

                                       20
<PAGE>

          (i)  files a motion to assume the Lease with the appropriate court;

          (ii) satisfies all of the  following  conditions,  which  Landlord and
               Tenant acknowledge to be commercially reasonable:

          (A)  cures  all  Defaults  of  Tenant  under  this  Lease or  provides
               Landlord with Adequate  Assurance (as defined below) that it will
               (x) cure all  monetary  Defaults of Tenant  hereunder  within ten
               (10)  days  from  the  date of the  assumption;  and (y) cure all
               nonmonetary  Defaults of Tenant hereunder within thirty (30) days
               from the date of the assumption;

          (B)  compensates  Landlord and any other person or entity, or provides
               Landlord with Adequate  Assurance that within ten (10) days after
               the date of the assumption,  it will compensate Landlord and such
               other person or entity,  for any pecuniary loss that Landlord and
               such other  person or entity  incurred as a result of any Default
               of Tenant, the trustee, or the debtor-in-possession;

          (C)  provides Landlord with Adequate  Assurance of Future  Performance
               (as  defined  below) of all of  Tenant's  obligations  under this
               Lease; and

          (D)  delivers  to  Landlord a written  statement  that the  conditions
               herein have been satisfied.

          (c)  For purposes only of the foregoing paragraph (b), and in addition
               to any other  requirements  under the Bankruptcy Code, any future
               federal   bankruptcy  law  and  applicable  case  law,  "Adequate
               Assurance" means at least meeting the following conditions, which
               Landlord and Tenant acknowledge to be commercially reasonable:

          (i)  entering an order segregating sufficient cash to pay Landlord and
               any other person or entity under paragraph (b) above; and

          (ii) granting to Landlord a valid first lien and security interest (in
               form  acceptable  to  Landlord) in all  property  comprising  the
               Tenant's  "property  of the  estate,"  as that term is defined in
               Section  541 of the  Bankruptcy  Code,  which  lien and  security
               interest   secures  the   trustee's   or   debtor-in-possession's
               obligation to cure the monetary and  nonmonetary  defaults  under
               the Lease within the periods set forth in paragraph (b) above.

          (d)  For purposes only of paragraph (b) above,  and in addition to any
               other  requirements under the Bankruptcy Code, any future federal
               bankruptcy law and applicable  case law,  "Adequate  Assurance of
               Future   Performance"   means  at  least  meeting  the  following
               conditions,   which   Landlord  and  Tenant   acknowledge  to  be
               commercially reasonable:

          (i)  the trustee or debtor-in-possession  depositing with Landlord, as
               security  for the  timely  payment  of rent  and  other  monetary
               obligations,  an amount equal to the sum of two (2) months' Basic
               Rent  plus an amount  equal to two (2)  months'  installments  on
               account of Additional Rent;

          (ii) the  trustee  or  the  debtor-in-possession  agreeing  to  pay in
               advance, on each day that the Basic Rent is payable,  the monthly
               installments on account of Additional Rent;

          (iii)the trustee or debtor-in-possession  providing adequate assurance
               of the source of the rent and other  consideration due under this
               Lease;

          (iv) Tenant's     bankruptcy     estate    and    the    trustee    or
               debtor-in-possession   providing   Adequate  Assurance  that  the
               bankruptcy  estate (and any successor after the conclusion of the
               Tenant's bankruptcy proceedings) will continue to have sufficient
               unencumbered  assets after the payment of all secured obligations
               and   administrative   expenses  to  assure   Landlord  that  the
               bankruptcy  estate (and any successor after the conclusion of the
               Tenant's  bankruptcy  proceedings)  will have sufficient funds to
               fulfill Tenant's obligations hereunder.

          (e)  If the  trustee  or the  debtor-in-possession  assumes  the Lease
               under  paragraph (b) above and applicable  bankruptcy law, it may
               assign its interest in this Lease only if the  proposed  assignee
               first  provides  Landlord  with  Adequate   Assurance  of  Future
               Performance of all of Tenant's  obligations  under the Lease, and
               if  Landlord  determines,  in  the  exercise  of  its  reasonable
               business  judgment,  that the  assignment  of this Lease will not
               breach any other lease, or any mortgage,  financing agreement, or
               other agreement relating to the Property by which Landlord or the
               Property  is then bound (and  Landlord  shall not be  required to
               obtain  consents or waivers from any third party  required  under
               any lease, mortgage, financing agreement, or other such agreement
               by which Landlord is then bound).

          (f)  For purposes only of paragraph (e) above,  and in addition to any
               other  requirements under the Bankruptcy Code, any future federal
               bankruptcy law and applicable  case law,  "Adequate  Assurance of
               Future  Performance"  means  at  least  the  satisfaction  of the
               following conditions, which Landlord and Tenant acknowledge to be
               commercially reasonable:

                                       21
<PAGE>

          (i)  the proposed assignee  submitting a current financial  statement,
               audited by a certified public accountant, that allows a net worth
               and  working  capital in  amounts  determined  in the  reasonable
               business  judgment  of Landlord  to be  sufficient  to assure the
               future  performance by the assignee of Tenant's  obligation under
               this Lease; and

          (ii) if  requested  by  Landlord  in the  exercise  of its  reasonable
               business  judgment,  the proposed assignee  obtaining a guarantee
               (in form and substance satisfactory to Landlord) from one or more
               persons who satisfy Landlord's standards of creditworthiness.

14.2 LANDLORD'S REMEDIES.

          (a)  Upon  the  occurrence  of  a  Default  of  Tenant,  Landlord  may
               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 Term of this Lease,  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 re-enter  the  Premises,  either by
               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.

          (c)  If this Lease  shall have been  terminated  as  provided  in this
               Article,  Tenant  shall pay the Basic Rent,  Additional  Rent and
               other sums payable  hereunder up to the time of such termination,
               and thereafter Tenant,  until the end of what would have been the
               Term of this  Lease  in the  absence  of  such  termination,  and
               whether  or not the  Premises  shall  have been  relet,  shall be
               liable to Landlord for, and shall pay to Landlord,  as liquidated
               current  damages the Basic Rent,  Additional  Rent and other sums
               that  would be  payable  hereunder  if such  termination  had not
               occurred,  less the net proceeds, if any, of any reletting of the
               Premises,  after deducting all reasonable  expenses in connection
               with  such  reletting,   including,   without   limitation,   all
               repossession  costs,  brokerage   commissions,   legal  expenses,
               attorneys' fees, advertising,  expenses of employees,  alteration
               costs and  expenses of  preparation  for such  reletting.  Tenant
               shall pay the portion of such current  damages  referred to above
               to  Landlord  monthly on the days which the Basic Rent would have
               been payable hereunder if this Lease had not been terminated.

          (d)  At any time after  termination  of this Lease as provided in this
               Article,  whether or not Landlord  shall have  collected any such
               current  damages,  as liquidated final damages and in lieu of all
               such  current  damages  beyond  the  date  of  such  demand,   at
               Landlord's  election Tenant shall pay to Landlord an amount equal
               to (1) the net present  value,  utilizing  the discount rate then
               being paid on U.S. Treasury  obligations having a term closest to
               what would have been the Term of this  Lease  absent  termination
               hereof,  of the excess,  if any, of the Basic Rent and Additional
               Rent  (including  Taxes,  Operating  Expenses  and other  charges
               payable under this Lease) which would be payable  hereunder  from
               the date of such demand (using the prior year's  Additional  Rent
               for such  calculation) over the then fair rental value (including
               Taxes,  Operating  Expenses and other charges  payable under this
               Lease) of the Premises for the same period.

          (e)  In  case of any  Default  of  Tenant,  re-entry,  expiration  and
               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 grant  concessions or free rent to the
               extent that Landlord considers  advisable and necessary to re-let
               the same and (ii) make such alterations,  repairs and decorations
               in the Premises as Landlord considers advisable and 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.  Tenant hereby  expressly waives any and all rights of
               redemption  granted by or under any present or future laws in the
               event of Tenant being evicted or dispossessed, or in the event of
               Landlord obtaining  possession of the Premises,  by reason of the
               violation by Tenant of any of the  covenants  and  conditions  of
               this Lease.

                                       22
<PAGE>

14.3 ADDITIONAL  RENT.  As referred to in Section 14.1 and  notwithstanding  any
     other provision of this Lease to the contrary,  if Tenant shall fail to pay
     when due any sums under this Lease designated as Additional Rent,  Landlord
     shall have the same  rights and  remedies  as Landlord  has  hereunder  for
     failure to pay Basic Rent.

14.4 LANDLORD'S  REMEDYING TENANT  DEFAULTS.  Landlord shall have the right, but
     shall not be  required,  twenty  (20) days after  notice to Tenant  stating
     Landlord's  intention  to exercise  self-help  remedies  (provided  that no
     notice shall be required, in Landlord's reasonable  discretion,  (1) in the
     event of  emergency,  (2) to remedy  Tenant's  failure  to carry  insurance
     required  hereunder,  or (3) to cure any lien which Tenant allows to attach
     to the  Premises),  to pay  such  sums or do any  act  which  requires  the
     expenditure  of monies which may be necessary or  appropriate  by reason of
     the failure or neglect of Tenant to perform any of the  provisions  of this
     Lease,  and in the event of the exercise of such right by Landlord,  Tenant
     agrees to pay to Landlord  forthwith  upon  demand all such sums,  together
     with  interest  thereon  at a rate equal to 3% over the base rate in effect
     from  time to time at  Fleet  Bank  (but in no event  greater  than 18% per
     annum),  as Additional Rent. Any payment of Basic Rent,  Additional Rent or
     other sums  payable  hereunder  not paid when due  shall,  at the option of
     Landlord,  bear interest at a rate equal to 3% over the base rate in effect
     from  time to time at  Fleet  Bank  (but in no event  greater  than 18% per
     annum) from the due date  thereof and shall be payable  forthwith on demand
     by Landlord, as Additional Rent.

14.5 REMEDIES  CUMULATIVE.  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.

14.6 ATTORNEYS' FEES.  Reasonable attorneys' fees and expenses incurred by or on
     behalf of Landlord in  enforcing  its rights hereunder or occasioned by any
     Default of Tenant shall be paid by Tenant.

14.7 WAIVER.

          (a)  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 the other's 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 any subsequent similar act by the other.

          (b)  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  of  the   earliest
               installment  of any payment due from Tenant under the  provisions
               hereof. 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.

14.8 SECURITY DEPOSIT.

          (a)  Tenant  agrees  that it shall  deliver  the  Security  Deposit to
               Landlord  simultaneously  with the execution and delivery of this
               Lease, in the form of a "Letter of Credit" which, as used herein,
               shall mean an unconditional standby irrevocable commercial letter
               of credit  that is:  (i) in the amount of the  Security  Deposit,
               (ii) issued by a commercial bank or savings and loan  institution
               reasonably  acceptable  to Landlord,  (iii)  binding for the Term
               hereof, as the same may be extended,  or renewable annually,  and
               (iv)  substantially  in the form attached hereto as Exhibit H. In
               the event that the Letter of Credit has an  ---------  expiration
               date prior to the expiration of the Term and has not been renewed
               by Tenant and  evidence  thereof  delivered  to Landlord at least
               thirty  (30)  days  prior to the  expiration  of said  Letter  of
               Credit,   Tenant  shall   substitute  a  new  Letter  of  Credit,
               conforming with the requirements  hereof, with an expiration date
               which is at least one (1) year  after the date of the  expiration
               date of the prior  Letter of  Credit.  If Tenant  fails to timely
               substitute  a new Letter of Credit by such date,  Landlord  shall
               have the right to draw on the  letter of credit and hold the cash
               proceeds  thereof as the Deposit as set forth in this Lease.  The
               Security  Deposit shall be held, paid and applied by the Landlord
               as set forth in this Lease.  Landlord may draw upon the Letter of
               Credit at any time after any Default of Tenant whereupon the cash
               proceeds thereof shall constitute the Security Deposit hereunder.

                                       23
<PAGE>

          (b)  Landlord shall hold the Security  Deposit  throughout the Term of
               this  Lease as  security  for the  performance  by  Tenant of all
               obligations on the part of Tenant hereunder.  Landlord shall have
               the  right  from  time to time,  without  prejudice  to any other
               remedy  Landlord  may have on  account  thereof,  to  apply  such
               deposit, or any part thereof, to Landlord's damages arising from,
               or to cure, any Default of Tenant. If Landlord shall so apply any
               or all of such Security  Deposit,  Tenant shall  immediately upon
               demand  deposit with Landlord the amount so applied to be held as
               security  hereunder.  Landlord shall return the Security Deposit,
               or so much thereof as shall not have  theretofore been applied in
               accordance  with the  terms of this  Section,  to  Tenant  on the
               expiration or earlier  termination  of the Term of this Lease and
               surrender of  possession of the Premises by Tenant to Landlord at
               such time,  provided  that there is then  existing  no Default of
               Tenant (nor any circumstance  which,  with the passage of time or
               the  giving of notice,  or both,  would  constitute  a Default of
               Tenant).  While  Landlord  holds the Security  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,
               Landlord shall disclose the existence of the Security  Deposit to
               the transferee and,  except for Holders,  which shall be governed
               by ARTICLE  13 herein,  require  that the  non-Holder  transferee
               assume all  obligations  of Landlord under this Lease relating to
               the unapplied portion of the Security  Deposit,  and the Security
               Deposit,  or any part  thereof  not  previously  applied,  may be
               turned  over by  Landlord to  Landlord's  transferee,  and, if so
               turned over,  Tenant agrees to look solely to such transferee for
               proper application of the Security Deposit in accordance with the
               terms of this  Section,  and the  return  thereof  in  accordance
               herewith.  The Holder of a Mortgage  shall not be  responsible to
               Tenant  for  the  return  or  application  of any  such  Security
               Deposit,  whether or not it succeeds to the  position of Landlord
               hereunder,  unless such Security Deposit shall have been received
               in hand by such Holder.

14.9 LANDLORD'S  DEFAULT.  Landlord  shall in no event be in default  under this
     Lease  unless  Landlord  shall  neglect  or  fail  to  perform  any  of its
     obligations  hereunder and shall fail to remedy the same within thirty (30)
     days after notice to Landlord  specifying  such  neglect or failure,  or if
     such failure is of such a nature that Landlord cannot reasonably remedy the
     same within such  thirty (30) day period,  Landlord  shall fail to commence
     promptly  (and in any event  within  such thirty (30) day period) to remedy
     the same and to prosecute  such remedy to  completion  with  diligence  and
     continuity.

14.10 TENANT  REMEDYING  LANDLORD'S  DEFAULT. Tenant  shall have the right,  but
     shall not be required,  twenty (20) days after  notice to Landlord  stating
     Tenant's intention to exercise self-help  remedies,  to pay such sums or do
     any act which requires the  expenditure of monies which may be necessary or
     appropriate  by reason of the failure or neglect of Landlord to perform any
     of the  provisions of this Lease,  and in the event of the exercise of such
     right by Tenant, Landlord agrees to pay to Tenant forthwith upon demand all
     such sums,  together with  interest  thereon at a rate equal to 3% over the
     base  rate in  effect  from  time to time at  Fleet  Bank  (but in no event
     greater than 18% per annum).

14.11 INDEPENDENT COVENANT.  Tenant  acknowledges  that its covenant to pay Rent
     hereunder is  independent  of Landlord's  obligation to act or refrain from
     acting  hereunder,  and that in the event  that  Tenant  shall have a claim
     against Landlord,  (including without limitation,  with respect to Tenant's
     right to self-help pursuant to Section 14.10 herein), Tenant shall not have
     the right to deduct the amount  allegedly  owed to Tenant  from any Rent or
     other sum payable to  Landlord,  it being  understood  that  Tenant's  sole
     remedy  for  recovering  upon such claim  shall be to bring an  independent
     legal action against Landlord.

                                   ARTICLE 15

                            MISCELLANEOUS PROVISIONS

15.1 RIGHTS OF  ACCESS.  Landlord  and Agent  shall  have the right to enter the
     Premises  at all  reasonable  hours  for  the  purpose  of  inspecting  the
     Premises,  doing maintenance or making repairs or otherwise  exercising its
     rights or fulfilling  its  obligations  under this Lease,  and Landlord and
     Agent also shall have the right to make access  available at all reasonable
     hours to prospective or existing mortgagees, purchasers or, during the last
     thirteen  (13)  months of the Term,  tenants  of any part of the  Property.
     During  any such  entry,  Landlord  shall  exercise  reasonable  efforts to
     prevent any disruption or  interference  with Tenant's use and enjoyment of
     the Premises.

15.2 COVENANT OF QUIET  ENJOYMENT.  Subject to the terms and  conditions of this
     Lease,  on  payment of the Basic Rent and  Additional  Rent and  observing,
     keeping and  performing all of the other terms and conditions of this Lease
     on Tenant's part to be observed, kept and performed, Tenant shall lawfully,
     peaceably  and quietly enjoy the Premises  during the term hereof,  without
     hindrance or ejection by any persons  lawfully  claiming  under Landlord to
     have title to the Premises  superior to Tenant.  The foregoing  covenant of
     quiet enjoyment is in lieu of any other covenant, express or implied.

                                       24
<PAGE>

15.3 LANDLORD'S LIABILITY.

          (a)  Tenant agrees to look solely to Landlord's equity interest in the
               Property at the time of  recovery  for  recovery of any  judgment
               against  Landlord,  and  agrees  that  neither  Landlord  nor any
               successor  of Landlord  shall 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
               any  successor of Landlord,  or to take any action not  involving
               the personal  liability of Landlord or any  successor of Landlord
               to respond in monetary damages from Landlord's  assets other than
               Landlord's equity interest in the Property.

          (b)  In no event shall  Landlord ever be liable to Tenant for any loss
               of  business  or any  other  indirect  or  consequential  damages
               suffered by Tenant from whatever cause.

          (c)  Where provision is made in this Lease for Landlord's consent, and
               Tenant shall  request such  consent,  and Landlord  shall fail or
               refuse to give such consent,  Tenant shall not be entitled to any
               damages for any withholding by Landlord of its consent,  it being
               intended  that  Tenant's  sole  remedy  shall  be an  action  for
               specific performance or injunction, and that such remedy shall be
               available only in those cases where Landlord has expressly agreed
               in writing not to unreasonably withhold its consent. Furthermore,
               whenever Tenant requests  Landlord's consent or approval (whether
               or not  provided for  herein),  Tenant shall pay to Landlord,  on
               demand,  as Additional Rent, any reasonable  expenses incurred by
               Landlord (including without limitation reasonable attorneys' fees
               and costs, if any) in connection therewith.

          (d)  Any repairs or  restoration  required or  permitted to be made by
               Landlord  under this  Lease may be made  during  normal  business
               hours, and Landlord shall have no liability for damages to Tenant
               for inconvenience,  annoyance or interruption of business arising
               therefrom,  but Landlord shall use reasonable efforts to minimize
               or prevent any such inconvenience, annoyance or interruption.

15.4 ESTOPPEL CERTIFICATE.  Landlord and Tenant shall, at any time and from time
     to time,  upon not less than ten (10) business days prior written notice by
     the  other,  execute,  acknowledge  and  deliver  to the other an  estoppel
     certificate  containing  such  statements  of fact as the other  reasonably
     requests.

15.5 BROKERAGE. Landlord and Tenant each warrant and represent to the other that
     it has dealt with no broker in  connection  with the  consummation  of this
     Lease other than Broker,  and, in the event of any brokerage claims against
     either party predicated upon dealings of the other party,  said other party
     shall  defend the same and  indemnify  the damaged  party  against any such
     claim.  Landlord  acknowledges  that  it is  obligated  to  make a  certain
     commission  payment to  Meredith & Grew,  Inc. (a portion of which is to be
     paid to Spaulding & Slye), upon the consummation of this Lease and upon any
     other conditions as may be set out in Landlord's  agreement with Meredith &
     Grew, Inc.

15.6 RULES AND REGULATIONS. Tenant shall abide by the Rules and Regulations from
     time to time  established by Landlord,  it being agreed that such Rules and
     Regulations   will  be   established   and   applied  by   Landlord   in  a
     non-discriminatory  fashion,  such that all Rules and Regulations  shall be
     generally  applicable to other tenants of the Building of similar nature to
     the Tenant  named  herein.  Landlord  agrees to use  reasonable  efforts to
     insure that any such Rules and  Regulations  are  uniformly  enforced,  but
     Landlord  shall not be liable to Tenant  for  violation  of the same by any
     other tenant or occupant of the Building,  or persons having  business with
     them.  In the event that there shall be a conflict  between  such Rules and
     Regulations and the provisions of this Lease,  the provisions of this Lease
     shall control. The Rules and Regulations  currently in effect are set forth
     in Exhibit E.

15.7 INVALIDITY  OF  PARTICULAR  PROVISIONS.  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.

15.8 PROVISIONS  BINDING,  ETC. 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 (except in the
     case of  Tenant,  only such  successors  and  assigns  as may be  permitted
     hereunder)  and, if Tenant shall be an  individual,  upon and to his heirs,
     executors, administrators,  successors and permitted 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.  Any  reference  in this Lease to
     successors  and assigns of Tenant shall not be  construed  to  constitute a
     consent to assignment by Tenant.

                                       25
<PAGE>

15.9 RECORDING. Tenant agrees not to record this Lease, but, if the Term of this
     Lease  (including  any Extension  Term) is seven (7) years or longer,  each
     party hereto  agrees,  on the request of the other,  to execute a notice of
     lease  substantially  in the form attached hereto as Exhibit I. In no event
     shall such document set forth the 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.  At  Landlord's
     request,  promptly upon  expiration of or earlier  termination of the Term,
     Tenant  shall  execute and  deliver to  Landlord a release of any  document
     recorded  in the real  property  records for the  location of the  Property
     evidencing  this Lease.  The obligations of Tenant under this Section shall
     survive the expiration or any earlier termination of the Term.

15.10 NOTICE. All notices or other communications required hereunder shall be in
     writing and shall be deemed duly given if delivered in person (with receipt
     therefor),  if sent by  reputable  overnight  delivery  or courier  service
     (e.g.,  Federal Express)  providing for receipted  delivery,  or if sent by
     certified or registered mail, return receipt requested, postage prepaid, to
     the following address:

          (a)  if to Landlord at Landlord's Address, to the attention of Karl W.
               Weller, Managing Director.

          (b)  if to Tenant,  at Tenant's  Address,  to the  attention  of Craig
               Dynes, and after the Commencement Date, at the Premises.

          Where receipt of notice or other  communication  shall be conclusively
          established by either (i) return of a return receipt  indicating  that
          the notice has been delivered; or (ii) return of the letter containing
          the notice with an indication  from the courier or postal service that
          the  addressee  has refused to accept  delivery of the notice.  Either
          party may change its address for the giving of notices by notice given
          in accordance with this Section.

15.11 WHEN LEASE BECOMES BINDING; ENTIRE AGREEMENT; MODIFICATION. 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.  This  Lease is the entire
     agreement between Landlord and Tenant, and this Lease expressly  supersedes
     any negotiations,  considerations,  representations  and understandings and
     proposals or other written  documents  relating  hereto.  This Lease 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.

15.12 PARAGRAPH HEADINGS AND INTERPRETATION OF SECTIONS.  The paragraph headings
     throughout  this instrument 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.  The  provisions  of this Lease shall be  construed as a whole,
     according  to  their  common   meaning   (except   where  a  precise  legal
     interpretation is clearly evidenced),  and not for or against either party.
     Use in this Lease of the words  "including,"  "such as" or words of similar
     import, when followed by any general term,  statement or matter,  shall not
     be  construed  to limit such  term,  statement  or matter to the  specified
     item(s),  whether  or not  language  of  non-limitation,  such as  "without
     limitation" or "including, but not limited to," or words of similar import,
     are used with reference thereto, but rather shall be deemed to refer to all
     other terms or matters that could fall within a  reasonably  broad scope of
     such term, statement or matter.

15.13 DISPUTE RESOLUTION.  In the event of a dispute between Landlord and Tenant
     pursuant  to this Lease  (other  than a dispute  relating to the payment of
     Basic Rent and  Additional  Rent) the parties  agree that prior to pursuing
     other available remedies  (excluding giving notices of default),  they will
     attempt to directly negotiate  resolution of their dispute.  If negotiation
     is unsuccessful,  then they agree to participate in at least three hours of
     mediation to be facilitated by a mediator mutually acceptable to them under
     the mediation  procedures set by the mediator.  The mediation session shall
     be  conducted  within  thirty  (30) days of the date on which the  mediator
     receives  the  request to  mediate.  The costs of such  mediation  shall be
     shared equally by the parties.

15.1 4WAIVER OF JURY TRIAL.  Landlord and Tenant hereby each waive trial by jury
     in any action,  proceeding or  counterclaim  brought by either  against the
     other, on or in respect of any matter  whatsoever  arising out of or in any
     way connected with this Lease,  the  relationship of Landlord and Tenant or
     Tenant's use or occupancy of the Premises.

15.15 TIME IS OF THE  ESSENCE.  Time is of the essence of each provision of this
     Lease.

15.16 MULTIPLE   COUNTERPARTS.   This  Lease  may  be   executed   in   multiple
     counterparts,  each of which shall be deemed an  original  and all of which
     together shall constitute one and the same document.

15.17 GOVERNING LAW.  This Lease  shall be  governed by the laws of the state in
     which the Property is located.

                                       26
<PAGE>

15.18 ROOF RIGHTS.

          (a)  Tenant.  Tenant  shall have the right to install  (subject to the
               provisions   of  this  Lease,   including   without   limitation,
               Attachments I and II to Exhibit E) and operate,  at Tenant's sole
               cost and expense, Tenant's Rooftop Equipment. As used herein, the
               term  "Tenant's  Rooftop   Equipment"  means   telecommunications
               equipment  installed on the roof of the Building and operated for
               Tenant's  sole  benefit,  and for which  Tenant  does not receive
               payment from any third party. Given Tenant's ongoing  obligations
               with respect to the  maintenance,  repair and  replacement of the
               roof of the Building, Tenant may, if there is no technical method
               of avoiding same, penetrate the roofing surface for such purpose.

          (b)  Landlord.  Notwithstanding  any other  provision of this Lease to
               the contrary,  (i) Landlord  shall have full rights of access to,
               and the right to place  telecommunications  equipment  upon,  the
               roof of the Building; provided, however, that such equipment does
               not unreasonably  interfere with any Tenant's  Rooftop  Equipment
               which is installed  prior to  Landlord's  installation,  and (ii)
               Landlord  shall  have  the  right  to  place   telecommunications
               equipment on the Land so long as the same does not interfere with
               vehicular access or parking at the Premises.

15.19 OWNERSHIP; PRIOR TENANT. Landlord hereby represents and warrants to Tenant
     that Landlord holds fee simple title to the Premises, subject to easements,
     restrictions,  reservations and encumbrances of record. Landlord represents
     and  warrants  to Tenant  that the prior  lease of the  Premises to Peritus
     Software has been terminated and is of no further force or effect.

15.20 AUTHORITY.  Landlord and Tenant each  represents and warrants to the other
     that it has full power and  authority  to enter into this  Lease,  and that
     this Lease has been approved by all requisite corporate action.

15.21 WARRANTIES.  Landlord agrees that it will cooperate with Tenant to enforce
     any  warranties  which  might be in effect from time to time on the roof or
     any other  portions  of the  Building  for  which  Tenant  has  maintenance
     responsibility under this Lease.



                                       27
<PAGE>



     IN WITNESS  WHEREOF,  Landlord and Tenant have caused this Lease to be duly
executed, under seal, by persons hereunto duly authorized,  as of the date first
set forth above.

               LANDLORD:

               BCIA NEW  ENGLAND  HOLDINGS  LLC,  a Delaware  limited  liability
               company

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

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

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

                             By:
                             Name:
                             Title:

               TENANT:

               SILVERSTREAM SOFTWARE, INC.

               By:
               Name:
               Title:


PABOS2:MFB:322611_7




                                       28
<PAGE>




                                                    A-1
                                    EXHIBIT A

                            LEGAL DESCRIPTION OF LAND






                                                    B-1
                                    EXHIBIT B

                              SITE PLAN OF BUILDING




                                                    C-1
                                    EXHIBIT C

                SCHEDULE OF LANDLORD'S FURNISHINGS AND EQUIPMENT

     As used herein,  the term "Landlord's  Furnishings and Equipment" means the
following items, collectively:

     o    Fifty (50) complete workstations installed on the second floor

     o    Reception desk located in main lobby

     o    Ten (10) cafeteria tables and thirty (30) cafeteria chairs

     o    Cafeteria serving table and non-commercial refrigerator

     o    Projection screens located throughout building, with exception of five
          (5) which have already been removed from second floor

     o    All building equipment and fixtures  permanently  attached,  excluding
          whiteboards, including but no limited to:

          o    Computer room Liebert cooling units;

          o    All telephone/data wiring;

          o    Security system including computer;

          o    All remaining  kitchen  equipment (as of 9/1/99):  refrigerators,
               ovens, racks, tables, etc.; and

          o    All remaining cable trays






                                       29
<PAGE>





                                                    D-4
                                    EXHIBIT D

                               OPERATING EXPENSES

Operating Expenses shall include the following, without limitation:

     1.   All expenses  incurred by Landlord or Landlord's agents which shall be
          directly  related  to  employment  of  personnel,   including  amounts
          incurred for wages,  salaries  and other  compensation  for  services,
          payroll,  social security,  unemployment and similar taxes,  workmen's
          compensation     insurance,     disability     benefits,     pensions,
          hospitalization,  retirement plans and group  insurance,  uniforms and
          working  clothes and the cleaning  thereof,  and  expenses  imposed on
          Landlord or Landlord's  agents  pursuant to any collective  bargaining
          agreement  for the  services of  employees  of Landlord or  Landlord's
          agents  in  connection  with  the  operation,   repair,   maintenance,
          cleaning,  management  and  protection  of  the  Property,  including,
          without limitation, day and night supervisors,  manager,  accountants,
          bookkeepers,  janitors, carpenters, engineers, mechanics, electricians
          and  plumbers  and  personnel  engaged  in  supervision  of any of the
          persons  mentioned above;  provided that, if any such employee is also
          employed on other  property of Landlord,  such  compensation  shall be
          suitably prorated among the Property and such other properties.

     2.   The cost of services,  utilities,  materials and supplies furnished or
          used in the operation,  repair,  replacement,  maintenance,  cleaning,
          repaving,  management  and  protection  of the Property or any portion
          thereof  (excluding  the  cost to  repair,  maintain  or  replace  the
          Structure of the Building which shall be conducted at Landlord's  sole
          cost  and  expense  other  than  New Law Work as  defined  in  Section
          7.2(a)),   including  without   limitation,   fees  paid  relating  to
          facilities  of the  Fields  Business  Park  and  such  matters  as are
          required to comply with law, including without limitation, any New Law
          Work.

     3.   The cost of replacements for tools and other similar equipment used in
          the repair,  maintenance,  cleaning and  protection  of the  Property,
          provided that, in the case of any such equipment used jointly on other
          property of Landlord,  such costs shall be suitably prorated among the
          Property and such other properties.

     4.   Where the Property is managed by Landlord or an affiliate of Landlord,
          an annual sum equal to the amounts  customarily  charged by management
          firms in the metropolitan Boston area for similar  properties,  but in
          no event more than five percent  (5%) of gross  annual Rent  hereunder
          (provided  that if Tenant  elects to perform the Exterior  Work,  then
          said  management  fee shall be reduced by 1% from the  management  fee
          that would be  charged if Tenant  were not  performing  such  Exterior
          Work),  whether or not actually  paid,  or where managed by other than
          Landlord or an affiliate thereof,  the amounts accrued for management,
          together  with,  in either case,  amounts  accrued for legal and other
          professional  fees relating to the Property,  but excluding  such fees
          and commissions paid in connection with services rendered for securing
          or  renewing  leases  and  for  matters  not  related  to  the  normal
          administration  and  operation of the Property  (Landlord  agreeing to
          provide a letter as of the  Commencement  Date stating the  management
          fee to be charged in the first Operating Year);

     5.   Premiums for  insurance  against  damage or loss to the Property  from
          such hazards as Landlord shall determine, including, but not by way of
          limitation,  insurance  covering loss of rent attributable to any such
          hazards, and public liability insurance.

     6.   If,  during  the Term of this  Lease,  Landlord  shall  make a capital
          expenditure to comply with law, including without limitation,  any New
          Law Work, or to reduce the costs of operating the Property,  the total
          cost of which is not properly includable in Operating Expenses for the
          Operating  Year in which it was  made,  there  shall  nevertheless  be
          included in such Operating Expenses for the Operating Year in which it
          was made and in Operating Expenses for each succeeding  Operating Year
          the annual charge-off of such capital  expenditure.  Annual charge-off
          shall be determined by dividing the original capital  expenditure plus
          an interest factor,  reasonably  determined by Landlord, as being ----
          the  interest  rate then being  charged  for  long-term  mortgages  by
          institutional  lenders on like properties within the locality in which
          the Property is located,  by the number of years of useful life of the
          capital   expenditure;   and  the  useful  life  shall  be  determined
          reasonably  by  Landlord  in  accordance   with   generally   accepted
          accounting  principles  and  practices in effect at the time of making
          such  expenditure.  Notwithstanding  the  foregoing,  with  respect to
          capital  expenditures  intended  to reduce the cost of  operating  the
          Property,  the amount  chargeable to Tenant hereunder shall not exceed
          the  amount  of the  actual  reduction  in the cost of  operating  the
          Property resulting from the capital expenditure in each operating Year
          or as otherwise agreed in writing by Landlord and Tenant.

                                       30
<PAGE>

     7.   Costs for  electricity,  water and  sewer use  charges,  gas and other
          utilities  supplied  to the  Property  and not  paid for  directly  by
          tenants.

     8.   Betterment assessments, provided the same are apportioned equally over
          the longest  period  permitted by law, and to the extent,  if any, not
          included in Taxes.

     9.   Amounts paid to independent  contractors  for services,  materials and
          supplies furnished for the operation,  repair,  maintenance,  cleaning
          and protection of the Property.

     Notwithstanding  anything to the contrary set forth in the Lease, Operating
Expenses shall not include the following:

     (i) Any ground or underlying lease rental;

     (ii) Bad debt expenses and interest, principal, points and fees on debts or
amortization on any mortgage or other debt  instrument  encumbering the Building
or the Land;

     (iii) Costs  incurred by Landlord to the extent that Landlord is reimbursed
by insurance proceeds or is otherwise reimbursed;

     (iv)  Depreciation,  amortization  and  interest  payments,  except  (1) on
equipment,  materials,  tools,  supplies and vendor-type  equipment purchased by
Landlord to enable Landlord to supply services Landlord might otherwise contract
for with a third  party  where  such  depreciation,  amortization  and  interest
payments would otherwise have been included in the charge for such third party's
services,  all as determined in accordance  with generally  accepted  accounting
principles,  consistently  applied,  and when  depreciation  or  amortization is
permitted  or  required,  the  item  shall  be  amortized  over  its  reasonably
anticipated useful life and (2) as set forth in Paragraph 6 above;

     (v) Advertising and promotional expenditures,  and costs of acquisition and
maintenance  of  signs  in or on  the  Building  identifying  the  owner  of the
Building;

     (vi) Expenses in connection  with services or other  benefits which are not
offered to Tenant or for which Tenant is charged directly;

     (vii)  Management  fees paid or charged by Landlord in connection  with the
management of the Building to the extent such management fee is in excess of the
amount set forth in the Lease;

     (viii) Salaries and other benefits paid to the employees of Landlord to the
extent attributable to personnel above the level of Building manager;

     (ix) Amounts paid to Landlord or to  subsidiaries or affiliates of Landlord
for goods  and/or  services in the  Building to the extent the same  exceeds the
costs of such goods and/or services rendered by unaffiliated  third parties on a
competitive basis;

     (x) Landlord's  general corporate  overhead and general and  administrative
expenses;

     (xi) Any  compensation  paid to  clerks,  attendants  or other  persons  in
commercial concessions operated by Landlord;

     (xii) Costs arising from Landlord's charitable or political contributions;

     (xiii) Costs arising from latent defects or repair thereof;

     (xix) Costs for  sculpture,  paintings or other objects of art,  except for
repair/replacement  with  objects of similar  quality of those  items  currently
located at the Property; and

     (xxi) Costs  associated with the  operation  of the  business of the entity
which  constitutes  Landlord  as the same are  distinguished  from the  costs of
operation of the Building,  including  accounting  and legal  matters,  costs of
defending any lawsuits  with any mortgagee  (except as the actions of Tenant may
be  in  issue),  costs  of  selling,  syndicating,   financing,   mortgaging  or
hypothecating  any of  Landlord's  interest in the Building,  costs  incurred in
connection  with  any  disputes  between  Landlord  and its  employees,  between
Landlord  and Building  management,  or between  Landlord  and other  tenants or
occupants,  but the  foregoing  shall not limit the amount  charged  pursuant to
Paragraph 4 of this Exhibit D.

     All assessments and premiums which are not  specifically  charged to Tenant
because of what Tenant has done,  which can be paid by Landlord in installments,
shall be paid by Landlord in the maximum number of installments permitted by law
without interest, penalty or other additional cost and not included as Operating
Expenses  except in the year in which the  assessment or premium  installment is
actually paid.


                                       31
<PAGE>

                                                    E-2
                                    EXHIBIT E

                        RULES AND REGULATIONS OF BUILDING

     The  following regulations are generally applicable:

     1.   The  public  sidewalks,   entrances,   passages,   courts,  elevators,
          vestibules,  stairways,  corridors or halls shall not be obstructed or
          encumbered by Tenant (except as necessary for  deliveries) or used for
          any purpose other than ingress and egress to and from the Premises.

     2.   No awnings,  curtains,  blinds,  shades,  screens or other projections
          shall be  attached  to or hung in,  or used in  connection  with,  any
          window of the  Premises  or any  outside  wall of the  Building.  Such
          awnings,  curtains.  blinds, shades, screens or other projections must
          be of a quality,  type,  design and color, and attached in the manner,
          approved by Landlord.

     3.   No show cases or other articles shall be put in front of or affixed to
          any part of the  exterior  of the  Building,  nor placed in the halls,
          corridors or vestibules.

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

     5.   Tenant  shall not use the  Premises or any part  thereof or permit the
          Premises  or any part  thereof  to be used for  manufacturing.  Tenant
          shall not use the  Premises or any part thereof or permit the Premises
          or any part  thereof to be used as a public  employment  bureau or for
          the sale of property of any kind at auction, except in connection with
          Tenant's business.

     6.   Tenant  must,  upon the  termination  of its  tenancy,  return  to the
          Landlord all locks,  cylinders and keys to offices and toilet rooms of
          the Premises.

     7.   No  vehicles  (other  than  bicycles)  or animals of any kind shall be
          brought into or kept in or about the Premises.

     8.   No tenant shall make, or permit to be made, any unseemly or disturbing
          noises  or  disturb  or  interfere  with  occupants  of  this  or  any
          neighboring  building or premises or those having  business  with them
          whether by use of any  musical  instrument,  radio,  talking  machine,
          unmusical noise,  whistling,  singing,  or in any other way. No tenant
          shall throw  anything  out of the doors,  windows or skylights or down
          the passageways.

     9.   The  Premises  shall not be used for  lodging or  sleeping  or for any
          immoral or illegal purpose.

     10.  No smoking shall be permitted in the Premises or the Building. Smoking
          shall only be permitted in smoking areas outside of the Building which
          have been designated by the Landlord.

     11.  Tenant   shall   cooperate   with   Landlord  in   obtaining   maximum
          effectiveness  of the  cooling  system by closing  draperies  when the
          sun's rays fall directly on windows of the Premises.

     12.  Tenant shall comply with all rules and  regulations  of the industrial
          Fields Business Park.

     13.  The rules and  regulations  set forth in Attachment I to this Exhibit,
          which is by this reference  made a part hereof,  are applicable to any
          Alterations being undertaken by or for Tenant in the Premises pursuant
          to Section 5.2 of the Lease:


                                       32
<PAGE>

                               ATTACHMENT I TO E-5
                            ATTACHMENT I TO EXHIBIT E

                  RULES AND REGULATIONS FOR TENANT ALTERATIONS

 A. GENERAL

     1.   All  Alterations  made by Tenant in, to or about the Premises shall be
          made in  accordance  with  the  requirements  of this  Exhibit  and by
          contractors or mechanics approved by Landlord.

     2.   Tenant  shall,  prior to the  commencement  of any  work,  submit  for
          Landlord's written approval, complete plans for the Alterations,  with
          full  details  and  specifications  for  all  of the  Alterations,  in
          compliance with Section D below.

     3.   Alterations  must  comply with the  Building  Code  applicable  to the
          Property and the  requirements,  rules and  regulations  and any other
          governmental agencies having jurisdiction.

     4.   No work shall be  permitted  to  commence  before  Tenant  obtains and
          furnishes  to Landlord  copies of all  necessary  licenses and permits
          from all governmental authorities having jurisdiction.

     5.   All  demolition,  removals  or  other  categories  of  work  that  may
          inconvenience  other tenants or disturb Building  operations,  must be
          scheduled and performed  before or after normal  business  hours,  and
          Tenant  shall  provide  Agent with at least 24 hours'  notice prior to
          proceeding with such work.

     6.   All inquiries,  submissions,  approvals and all other matters shall be
          processed through Agent.

     7.   All work,  if  performed by a contractor  or  subcontractor,  shall be
          subject  to  reasonable   supervision  and  inspection  by  Landlord's
          representative.  Such  supervision and inspection shall be at Tenant's
          sole expense and Tenant shall pay  Landlord's  reasonable  charges for
          such supervision and inspection.

B.   PRIOR TO COMMENCEMENT OF WORK

     1.   Tenant shall  submit to the Building  manager a request to perform the
          work. The request shall include the following enclosures:

          (a)  A  list  of  Tenant's   contractors  and/or   subcontractors  for
               Landlord's approval.

          (b)  Four complete sets of plans and  specifications  properly stamped
               by a registered architect or professional engineer.

          (c)  A properly executed building permit application form.

          (d)  Four executed copies of the Insurance  Requirements  Agreement in
               the form  attached to this  Exhibit as  Attachment  II and made a
               part  hereof  from  Tenant's  contractor  and,  if  requested  by
               Landlord, from the contractor's subcontractors.

          (e)  Contractor's   and   subcontractor's    insurance   certificates,
               including  an  indemnity  in   accordance   with  the   Insurance
               Requirements Agreement.

     2.   Landlord will return the following to Tenant:

          (a)  Two  sets  of  plans  approved  or a  disapproved  with  specific
               comments as to the reasons  therefor  (such  approval or comments
               shall  not  constitute  a  waiver  of  approval  of  governmental
               authorities).

          (b)  Two  fully   executed   copies  of  the  Insurance   Requirements
               Agreement.

     3.   Landlord's  approval of the plans,  drawings,  specifications or other
          submissions in respect of any Alterations shall create no liability or
          responsibility on the part of Landlord for their completeness,  design
          sufficiency or compliance with  requirements  of any applicable  laws,
          rules or regulations of any governmental or quasi-governmental agency,
          board or authority.

     4.   Tenant shall obtain a building permit from the Building Department and
          necessary permits from other  governmental  agencies.  Tenant shall be
          responsible  for keeping  current all  permits.  Tenant  shall  submit
          copies of all  approved  plans and permits to Landlord  and shall post
          the original  permit on the Premises prior to the  commencement of any
          work.

                                       33
<PAGE>

C.   REQUIREMENTS AND PROCEDURES

     1.   All  structural  and floor  loading  requirements  of Tenant  shall be
          subject to the prior  approval of  Landlord's  structural  engineer at
          Tenant's sole cost and expense.

     2.   All   mechanical   (HVAC,   plumbing  and  sprinkler)  and  electrical
          requirements shall be subject to the approval of Landlord's mechanical
          and electrical  engineers and all mechanical and electrical work shall
          be   performed  by   contractors   who  are  engaged  by  Landlord  in
          constructing,  operating or maintaining the Building.  When necessary,
          Landlord will require  engineering  and shop drawings,  which drawings
          must be approved by Landlord  before work is started.  Drawings are to
          be prepared by Tenant and all approvals shall be obtained by Tenant.

     3.   No  material  or  equipment  shall  be  carried  under  or on  top  of
          elevators.

     4.   If shutdown of risers and mains for  electrical,  life safety  system,
          HVAC,  sprinkler  and plumbing  work is  required,  such work shall be
          supervised by Landlord's representative.  No work will be performed in
          Building  mechanical  equipment rooms without Landlord's  approval and
          under Landlord's supervision.

     5.   Tenant's contractor shall:

          (a)  have a superintendent or foreman on the Premises at all times;

          (b)  police the job at all times,  continually  keeping  the  Premises
               orderly;

          (c)  maintain  cleanliness  and  protection  of all  areas,  including
               elevators and lobbies.

          (d)  protect  the  front  and top of all  peripheral  HVAC  units  and
               thoroughly clean them at the completion of work;

          (e)  block off supply and return  grills,  diffusers and ducts to keep
               dust from entering into the Building air conditioning system; and

     6.   If Tenant's  contractor  is negligent in any of its  responsibilities,
          Tenant shall be charged for corrective work.

     7.   All  equipment  and  installations  must  be  equal  to the  standards
          generally in effect with respect to the remainder of the Building. Any
          deviation  from such  standards will be permitted only if indicated or
          specified on the plans and specifications and approved by Landlord.

     8.   A properly  executed air  balancing  report  signed by a  professional
          engineer  shall be submitted to Landlord  upon the  completion  of all
          HVAC work.

     9.   Upon completion of the Alterations,  Tenant shall submit to Landlord a
          permanent  certificate  of occupancy  and final  approval by the other
          governmental agencies having jurisdiction.

     10.  Tenant  shall  submit to Landlord a final  "as-built"  set of drawings
          showing all items of the Alterations in full detail, in both hard copy
          and electronic form.

     11.  Additional  and  differing  provisions  in the Lease,  if any, will be
          applicable and will take precedence.

D.   STANDARDS FOR PLANS AND SPECIFICATIONS.

     Whenever Tenant shall be required by the terms of the Lease (including this
Exhibit) to submit plans to Landlord in connection  with any  Alterations,  such
plans shall include at least the following:

     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.,
          photocopiers, etc.

     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 specifications of floor covering,  paint or paneling with
          paint colors referenced to standard color system.

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

                                       34
<PAGE>

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

     9.   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.

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

     11.  Location and weights of storage files.

     12.  Location of any special soundproofing requirements.

     13.  Location  and details of special  floor areas  exceeding  50 pounds of
          live load per square foot.

     14.  All structural,  mechanical,  plumbing and electrical drawings,  to be
          prepared  by the base  building  consulting  engineers,  necessary  to
          complete the Premises in accordance with Tenant's Plans.

     15.  All drawings to be uniform size (30" x 46") and shall  incorporate the
          standard project  electrical and plumbing symbols and be at a scale of
          1/8" = 1' or larger.

     16.  All drawings shall be stamped by an architect  (or, where  applicable,
          an  engineer)  licensed in the  jurisdiction  in which the Property is
          located and without limiting the foregoing, shall be sufficient in all
          respects for submission to applicable authorization in connection with
          a building permit application.

                                       35
<PAGE>


                              ATTACHMENT II TO E-3
                           ATTACHMENT II TO EXHIBIT E

                       CONTRACTOR'S INSURANCE REQUIREMENTS

Building: 2 Federal Street, Billerica, Massachusetts

Landlord: BCIA New England Holdings LLC

Tenant:   Silverstream Software, Inc.

     The undersigned  contractor or subcontractor  ("Contractor") has been hired
by the tenant named above  (hereinafter  called  "Tenant") of the Premises named
above (or by Tenant's contractor) to perform certain work ("Work") for Tenant in
the Premises identified above. Contractor and Tenant have requested the landlord
named above  ("Landlord")  to grant  Contractor  access to the  Premises and its
facilities in connection  with the  performance of the Work, and Landlord agrees
to grant such access to Contractor  upon and subject to the following  terms and
conditions:

     1.   Contractor  agrees to  indemnify  and save  harmless  Landlord and its
          respective  officers,  employees  and  agents  and  their  affiliates,
          subsidiaries and partners,  and each of them, from and with respect to
          any  claims,  demands,  suits,   liabilities,   losses  and  expenses,
          including reasonable  attorneys' fees, arising out of or in connection
          with the Work (and/or  imposed by law upon any or all of them) because
          of  personal  injuries,  bodily  injury  (including  death at any time
          resulting  therefrom)  and loss of or  damage to  property,  including
          consequential damages, whether such injuries to person or property are
          claimed to be due to negligence of the Contractor, Tenant, Landlord or
          any other party entitled to be indemnified as aforesaid  except to the
          extent specifically  prohibited by law (and any such prohibition shall
          not void this  Agreement  but  shall be  applied  only to the  minimum
          extent required by law).

     2.   Contractor  shall  provide  and  maintain  at its own  expense,  until
          completion of the Work, the following insurance:

          (1)  Workmen's   Compensation  and  Employers,   Liability   Insurance
               covering  each and every  workman  employed in, about or upon the
               Work,  as provided for in each and every  statute  applicable  to
               Workmen's Compensation and Employers' Liability Insurance.

          (2)  Comprehensive General Liability Insurance including coverages for
               Protective and  Contractual  Liability (to  specifically  include
               coverage for the  indemnification  clause of this  Agreement) for
               not less than the following limits:

                           Personal Injury:
                           $3,000,000 per person
                           $10,000,000 per occurrence

                           Property Damage:
                           $3,000,000 per occurrence $3,000,000 aggregate

          (3)  Comprehensive Automobile Liability Insurance (covering all owned,
               non-owned  and/or hired motor  vehicles to be used in  connection
               with the Work) for not less than the following limits:

                           Bodily Injury:
                           $1,000,000 per person
                           $1,000,000 per occurrence

                           Property Damage:
                           $1,000,000 per occurrence

     Contractor  shall  furnish a  certificate  from its  insurance  carrier  or
carriers to the Premises office before commencing the Work,  showing that it has
complied with the above requirements  regarding insurance and providing that the
insurer  will  give  Landlord  ten  (10)  days'  prior  written  notice  of  the
cancellation of any of the foregoing policies.

          3.   Contractor shall require all of its subcontractors engaged in the
               Work to provide the following insurance:

               (1)  Comprehensive    General   Liability   Insurance   including
                    Protective and Contractual  Liability  coverages with limits
                    of  liability  at  least  equal  to  the  limits  stated  in
                    paragraph 2(b).

               (2)  Comprehensive  Automobile  Liability Insurance (covering all
                    owned,  non-owned  and/or hired motor vehicles to be used in
                    connection  with the Work) with limits of liability at least
                    equal to the limits stated in paragraph 2(c).

                                       36
<PAGE>

     Upon  the  request  of  Landlord,  Contractor  shall  require  all  of  its
subcontractors  engaged  in  the  Work  to  execute  an  Insurance  Requirements
agreement in the same form as this Agreement.

     Agreed to and executed this day of___________________, 199_.

                                        Contractor:

                                         By:


                                         By:


                                         By:


                                       37
<PAGE>



                                                    F-1
                                    EXHIBIT F

                  APPRAISERS' DETERMINATION OF FAIR MARKET RENT

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

For the purpose of fixing the Fair Market Rent for the Extension Term,  Landlord
and Tenant shall agree upon an appraiser who shall be a member of the M.A.I.  or
A.S.R.E.C. (or successor professional organizations) and shall have at least ten
(10) years experience  appraising  rental values of property in the metropolitan
Boston market area.

If Landlord and Tenant are not able to agree upon an appraiser by the date which
is ten (10) days after an  Impasse,  as defined in Section  1.1 (the  "Appraiser
Selection  Deadline"),  each of  Landlord  and  Tenant  shall,  within  ten (10)
additional  days,  that is,  by the date  which is  twenty  (20)  days  after an
Impasse, select an appraiser with the foregoing qualifications whereupon each of
said appraisers shall, within five (5) days of their selection hereunder, select
a third  appraiser with the foregoing  qualifications.  The Fair Market Rent for
the Extension Term shall  thereafter be determined to be the amount equal to the
average of the two  appraisals  which are closest in dollar amount to each other
except  that if all  three  appraisals  are  apart  in equal  amounts,  then the
appraisal  which  falls in the  middle  shall be the  Fair  Market  Rent for the
Extension  Term.  If either party fails to select an appraiser by the  Appraiser
Selection Deadline,  then the appraiser selected by the other party, if selected
by the Appraiser Selection Deadline,  shall be the sole appraiser.  Landlord and
Tenant  shall  share  equally  the  expense  of  any  and  all  appraisers.  The
appraiser(s)  shall be  obligated  to make a  determination  of Fair Market Rent
within thirty (30) days of the  appointment  of either the single  appraiser (if
only one) and within thirty (30) days of the  appointment of the third appraiser
(if three are so appointed).

In determining the Fair Market Rent for the Extension Term, the appraisers shall
utilize customary appraisal methods.

The  appraisers  shall not have the right to modify any  provision of this Lease
and shall only  determine the Fair Market Rent which shall  constitute the Basic
Rent under this Lease for the Extension Term.



                                       38
<PAGE>


                                                    G-7
                                    EXHIBIT G

         FORM OF SUBORDINATION, NON-DISTURBANCE AND ATTORNMENT AGREEMENT

                         SUBORDINATION, NON-DISTURBANCE,

                            AND ATTORNMENT AGREEMENT

THIS AGREEMENT is made and entered into as of the _______ day of ______________,
199__, by and between General Electric Capital Corporation, a New York

corporation ("Mortgagee"), and, a __________________________________ ("Lessee").


                                R E C I T A L S:

     A. Mortgagee  is  making  a  loan of up to $___________ (the "Loan")  to, a
_________________, ("Borrower"), secured by  the Borrower's interest in the real
property  described  in  Exhibit A attached  hereto and  incorporated  herein by
reference  (said  real  property  and  improvements  being   herein  called  the
"Project"), such  Loan  being  secured by a Deed of Trust and Security Agreement
dated ___________________(the "Mortgage"), constituting a lien or encumbrance on
the Project; and


     B. Lessee is the  holder of a leasehold estate in and to _______________ of
_____________ of the Project, consisting  of approximately _______ usable square
feet of space (the "Demised Premises"), under that Lease Agreement(the  "Lease")
dated _______,  executed  by  Borrower, as  Landlord  (Borrower  being sometimes
hereinafter called "Lessor"), and Lessee, as Tenant; and


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

                               A G R E E M E N T:

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

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

     2.  ATTORNMENT.  If the interests of Lessor in and to the Demised  Premises
are owned by Mortgagee by reason of any  deed-in-lieu of  foreclosure,  judicial
foreclosure,  sale pursuant to any power of sale or other proceedings brought by
it or by any other manner,  including,  but not limited to, Mortgagee's exercise
of its rights under any assignment of leases and rents,  and Mortgagee  succeeds
to the  interest of Lessor  under the Lease,  Lessee shall be bound to Mortgagee
under all of the terms, covenants and conditions of the Lease for the balance of
the term thereof  remaining and any extension  thereof duly  exercised by Lessee
with the same force and effect as if Mortgagee  were the Lessor under the Lease;
and Lessee does hereby attorn to Mortgagee, as its lessor, said attornment to be
effective and  self-operative,  without the execution of any further instruments
on the  part  of  any  of  the  parties  hereto,  immediately  upon  Mortgagee's
succeeding to the interest of Lessor under the Lease;  provided,  however,  that
Lessee  shall be under no  obligation  to pay  rent to  Mortgagee  until  Lessee
receives  written  notice from  Mortgagee  that  Mortgagee  has succeeded to the
interest  of the Lessor  under the Lease or  otherwise  has the right to receive
such rents.  The respective  rights and obligations of Lessee and Mortgagee upon
such attornment,  to the extent of the then remaining balance of the term of the
Lease,  shall  be and  are the  same as now set  forth  therein,  it  being  the
intention  of the parties  hereto for this purpose to  incorporate  the Lease in
this  Agreement by reference,  with the same force and effect as if set forth in
full herein.

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

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

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

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

                                       39
<PAGE>

     (d)  Bound by the $300,000  Letter of Credit held as a Security  Deposit by
          Landlord or by any other  security or advance  rental  deposit made by
          Lessee  which is not  delivered  or paid  over to  Mortgagee  and with
          respect  to which  Lessee  shall  look  solely to Lessor for refund or
          reimbursement;

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

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

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

     Neither General Electric  Capital  Corporation nor any other party who from
time to time shall be included in the definition of Mortgagee  hereunder,  shall
have any  liability  or  responsibility  under or  pursuant to the terms of this
Agreement  after it ceases to own an  interest in the  Project.  Nothing in this
Agreement  shall be construed to require  Mortgagee to see to the application of
the proceeds of the Loan, and Lessee's  agreements set forth herein shall not be
impaired on account of any modification of the documents evidencing and securing
the Loan.  Lessee  acknowledges  that Mortgagee is obligated only to Borrower to
make the Loan only upon the terms and subject to the conditions set forth in the
Loan  Agreement  between  Mortgagee  and Borrower  pertaining to the Loan. In no
event shall Mortgagee or any purchaser of the Project at foreclosure sale or any
grantee of the Project named in a  deed-in-lieu  of  foreclosure,  nor any heir,
legal representative,  successor, or assignee of Mortgagee or any such purchaser
or grantee  (collectively the Mortgagee,  such purchaser,  grantee,  heir, legal
representative,  successor  or assignee,  the  "Subsequent  Landlord")  have any
personal  liability for the obligations of Lessor under the Lease and should the
Subsequent  Landlord  succeed to the  interests  of the Lessor  under the Lease,
Tenant  shall  look  only to the  estate  and  property  of any such  Subsequent
Landlord in the  Project  for the  satisfaction  of  Tenant's  remedies  for the
collection of a judgment (or other  judicial  process)  requiring the payment of
money in the event of any default by any  Subsequent  Landlord as landlord under
the Lease,  and no other property or assets of any Subsequent  Landlord shall be
subject to levy,  execution or other enforcement  procedure for the satisfaction
of Tenant's remedies under or with respect to the Lease; provided, however, that
the Lessee may exercise any other right or remedy provided  thereby or by law in
the event of any failure by Lessor to perform any such material obligation.

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

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

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

                                       40
<PAGE>

                General Electric Capital Corporation
                c/o GE Capital Asset Management Corporation
                North Sam Houston Parkway East, Suite 1200
                Houston, Texas 77060
                Attention:  Robert H. Hayes

                and

                General Electric Capital Corporation
                Long Ridge Road
                Stamford, Connecticut 06927
                Attention:  Vice President, Securitizations

     7.  MORTGAGEE.  The term  "Mortgagee"  shall be deemed to  include  General
Electric  Capital  Corporation and any of its successors and assigns,  including
anyone who shall have succeeded to Lessor's interest in and to the Lease and the
Project by,  through or under  judicial  foreclosure  or sale under any power or
other  proceedings  brought  pursuant to the  Mortgage,  or deed in lieu of such
foreclosure or proceedings, or otherwise.

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


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

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

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

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

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

          (f)  That  Landlord has not yet provided and is obligated to provide a
               Landlord  Contribution of $600,000 pursuant to Section 4.2 of the
               Lease and is  obligated  to  deliver  the  Premises  in a certain
               condition as  described  in Section  4.2(c) and 7.1 of the Lease;
               and

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

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

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


                                       41
<PAGE>



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

MORTGAGEE:                   GENERAL ELECTRIC CAPITAL CORPORATION,
                                  a New York corporation

                             By:
                             Name:
                             Title:



LESSEE:                      SILVERSTREAM SOFTWARE, INC.,
                               a Delaware corporation

                             By:
                             Name:
                             Title:


                                       42
<PAGE>


STATE OF _____________________________ss.

COUNTY OF ____________________________ss.


     This instrument was acknowledged before me on this ____ day of ___________,
199_, by ________________________, _______________ of _________________________,
a ____________________, on behalf of said corporation.




(SEAL)
                                       ________________________________________
                                       Notary Public in and
                                       for the State of __________

                                       ________________________________________
                                       Print name of notary

                                       My Commission Expires:__________________

STATE OF _____________________________ss.

COUNTY OF ____________________________ss.

     This instrument was acknowledged before me on this ____ day of____________,
199_, by ________________________, _______________ of _________________________,
a ____________________, on behalf of said corporation.



(SEAL)
                                       ________________________________________
                                       Notary Public in and
                                       for the State of __________

                                       ________________________________________
                                       Print name of notary

                                       My Commission Expires:__________________


                                       43
<PAGE>

                                                    H-2
                                    EXHIBIT H

                            Form of Letter of Credit

                                                     _________________, 1999

____________________
____________________
____________________
____________________

        Re: Letter of Credit No.:_________

Gentlemen:

     We hereby  establish our Irrevocable and  Transferable  Letter of Credit in
your favor by  order and for the account of _____________________, for a sum not
exceeding  Dollars  United  States  Currency ($________) available by your sight
draft  on  us accompanied by:

     A letter(the "Letter") purportedly signed by an officer of_________________
     (together with its successors and assigns, the "Beneficiary") to the effect
     that  a  default  by  the  Tenant  in  the  payment  or  performance of its
     obligations  under the Lease  has occurred  and such  default has not  been
     cured  within  the applicable grace period, if any.

     Partial drawings are permitted under this Irrevocable Letter of Credit.

     Each draft drawn hereunder must be marked "Drawn under ____________________
     Bank, Credit No. __________________, dated ____________________".


     We engage  with you that a draft  accompanied  by the Letter  shall be duly
honored  by  us  simultaneously  upon the presentation  thereof at our office at
at _________________________ any time on or before the expiration of the Term of
the Lease.

     This Letter of Credit is transferable solely on the condition that:

          The  Beneficiary  proposing to transfer  furnishes to us a request for
          transfer  in writing  and the  original  of this  Letter of Credit for
          appropriate  endorsement.  When  transferred in accordance  with these
          provisions, the draft and the accompanying Letter may be executed only
          by the transferee.



________________________, 1999


     This Letter of Credit is subject to Article 5 of the Massachusetts
Uniform  Commercial  Code and where not  inconsistent  therewith  to the Uniform
Customs and Practices for  Documentary  Credits (1983  Revision),  International
Chamber of Commerce, Paris, France, Publication 400.

                                        Very truly yours,

                                        __________________ Bank

                                        By: _______________________
                                              _______________, Its _____________
                                              Hereunto duly authorized



                                       44
<PAGE>


                                                    I-3
                                    EXHIBIT I

                             FORM OF NOTICE OF LEASE

     Pursuant to Massachusetts  General Laws,  Chapter 183, Section 4, notice is
hereby given of the following Lease:

Landlord: BCIA New England Holdings LLC, a Delaware limited  liability  company,
          having  a   principal  place   of  business  at  c/o   Boston  Capital
          Institutional  Advisors  LLC, One  Boston Place, Boston, Massachusetts
          02108.


Tenant:   Silverstream Software, Inc., a ___________________ corporation, having
          its principal office at 2 Federal Street, Billerica, Massachusetts.


Date of
Lease:    _____________________, 1999.


Description
of
Leased
Premises: The land  located in Billerica, Massachusetts, together with the two-
          story  building  located  thereon, commonly  known  and  numbered as 2
          Federal Street.


Term of
Lease:    Six (6) years


Extension
Option:   One (1) option to renew for a term of five (5) years


     This  instrument  is executed as notice of the  aforesaid  Lease and is not
intended,  nor shall it be deemed,  to vary or govern the  interpretation of the
terms and conditions thereof.




                                       45
<PAGE>




          EXECUTED as a sealed instrument this ___ day of________________, 1999.


               LANDLORD:

               BCIA NEW  ENGLAND  HOLDINGS  LLC,  a Delaware  limited  liability
               company

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

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

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

                             By:
                             Name:
                             Title:

               TENANT:

               SILVERSTREAM SOFTWARE, INC.

               By:
               Name:
               Title:





                                       46
<PAGE>




STATE OF _____________________________ss.

COUNTY OF ____________________________ss.


     This instrument was acknowledged before me on this ____ day of ___________,
199_, by ________________________, _______________ of _________________________,
a ____________________, on behalf of said corporation.




(SEAL)
                                       ________________________________________
                                       Notary Public in and
                                       for the State of __________

                                       ________________________________________
                                       Print name of notary

                                       My Commission Expires:__________________

STATE OF _____________________________ss.

COUNTY OF ____________________________ss.

     This instrument was acknowledged before me on this ____ day of____________,
199_, by ________________________, _______________ of _________________________,
a ____________________, on behalf of said corporation.



(SEAL)
                                       ________________________________________
                                       Notary Public in and
                                       for the State of __________

                                       ________________________________________
                                       Print name of notary

                                       My Commission Expires:__________________


                                       47
<PAGE>