DS2.369722.6
                                                                  Execution Copy









                             LEASE AGREEMENT BETWEEN



            W9/TIB REAL ESTATE LIMITED PARTNERSHIP, AS LANDLORD, AND



                         KRONOS INCORPORATED, AS TENANT



                             DATED February 26, 1999


                                     <PAGE>



                                        v

                                TABLE OF CONTENTS

1.       Lease Grant.........................................................1

2.       Term................................................................1

3.       Rent................................................................1
         (a)      Basic Rent.................................................1
         (b)      Payment....................................................2
         (c)      Operating Costs............................................2

4.       Delinquent Payment; Handling Charges................................5

5.       Security Deposit....................................................5

6.       Landlord's Obligations..............................................6
         (a)      Services...................................................6
         (b)      Landlord's Maintenance Obligations.........................8
         (c)      Excess Utility Use.........................................8
         (d)      Restoration of Services; Abatement.........................9
         (e)      Taxes......................................................9
         (f)      Landlord's Insurance.......................................9

7.       Improvements; Alterations; Repairs; Maintenance.....................9
         (a)      Improvements; Alterations..................................9
         (b)      Repairs; Maintenance......................................10
         (c)      Performance of Work.......................................11
         (d)      Mechanic's Liens..........................................11
         (e)      Utilities.................................................11
         (f)      Floor Load; Heavy Machinery...............................11

8.       Use................................................................12

9.       Assignment and Subletting..........................................12
         (a)      Transfers; Consent........................................12
         (b)      Cancellation..............................................13
         (c)      Additional Compensation...................................13

10.      Insurance; Waivers; Subrogation; Indemnity.........................14
         (a)      Insurance.................................................14
         (b)      Waiver of Negligence; No Subrogation......................14
         (c)      Indemnity.................................................14

11.      Subordination; Attornment; Notice to Landlord's Mortgagee..........15
         (a)      Subordination.............................................15
         (b)      Attornment................................................15
         (c)      Notice to Landlord's Mortgagee............................15
         (d)      Landlord's Mortgagee's Protection Provisions..............15

12.      Rules and Regulations..............................................16

13.      Condemnation.......................................................16
         (a)      Total Taking..............................................16
         (b)      Partial Taking -Tenant's Rights...........................16
         (c)      Partial Taking -Landlord's Rights.........................16
         (d)      Award.....................................................17

14.      Fire or Other Casualty.............................................17
         (a)      Repair Estimate...........................................17
         (b)      Landlord's and Tenant's Rights............................17
         (c)      Landlord's Rights.........................................17
         (d)      Repair Obligation.........................................18

15.      Personal Property Taxes............................................18

16.      Events of Default..................................................18

17.      Remedies...........................................................19

18.      Payment by Tenant; Non-Waiver......................................20
         (a)      Payment by Tenant.........................................20
         (b)      No Waiver.................................................20

19.      Landlord's Lien....................................................20

20.      Surrender of Premises..............................................21

21.      Holding Over.......................................................21

22.      Certain Rights Reserved by Landlord................................21

23.      [Intentionally Omitted]............................................22

24.      Miscellaneous......................................................22
         (a)      Landlord Transfer.........................................22
         (b)      Landlord's Liability......................................22
         (c)      Force Majeure.............................................22
         (d)      Brokerage.................................................22
         (e)      Estoppel Certificates.....................................23
         (f)      Notices...................................................23
         (g)      Separability..............................................23
         (h)      Amendments; and Binding Effect............................23
         (i)      Quiet Enjoyment...........................................23
         (j)      No Merger.................................................23
         (k)      No Offer..................................................24
         (l)      Entire Agreement..........................................24
         (m)      Waiver of Jury Trial......................................24
         (n)      Governing Law.............................................24
         (o)      Joint and Several Liability...............................24
         (p)      Financial Reports.........................................24
         (q)      Landlord's Fees...........................................24
         (r)      Telecommunications........................................25
         (s)      General Definitions.......................................25
         (t)      Confidentiality...........................................25
         (u)      Hazardous Materials.......................................25
         (v)      List of Exhibits..........................................26
         (w)      Time of Essence...........................................26
         (x)      Notice of Lease...........................................26
         (y)      First Amendment to Lease..................................26
         (z)      Corporate Approval........................................27
         (aa)     Building Signage..........................................27
         (bb)     Rooftop Equipment.........................................27
         (cc)     Access....................................................28
         (dd)     Arbitration...............................................28
         (ee)     Campus Setting............................................29
         (ff)     Termination Agreement with Sun Microsystems...............30
         (gg)     Termination of 6 Omni Way Lease...........................30

25.      Other Provisions...................................................31



<PAGE>





                                                        LEASE


         THIS LEASE  AGREEMENT (this "Lease") is entered into as of February 26,
1999,  between  W9/TIB  REAL  ESTATE  LIMITED  PARTNERSHIP,  a Delaware  limited
partnership ("Landlord"),  and KRONOS INCORPORATED,  a Massachusetts corporation
("Tenant").

         1. Lease Grant. Subject to the terms of this Lease,  Landlord leases to
Tenant,  and Tenant leases from Landlord,  real property  located at 2 Omni Way,
Chelmsford,   Massachusetts  together  with  all  improvements  located  thereon
including the office building located thereon  containing  approximately  82,228
rentable square feet (the "Premises"), as shown on the site plan attached hereto
as Exhibit A. The office building  located on the Premises shall  hereinafter be
referred  to as the  "Building").  The  legal  description  of the  Premises  is
attached hereto as Exhibit B.

         2. Term.  The term of this Lease  shall  commence on the earlier of (i)
the date  which is one  hundred  twenty  (120)  days  after the date upon  which
Landlord  provides to Tenant written notice of  availability  of the Premises or
(ii) the date upon which Tenant occupies the Premises for the Permitted Use, but
in no event  shall  such date be later  than  July 1,  1999  (the  "Commencement
Date"), and expiring on the last day of the month in which the thirteenth (13th)
anniversary of the Commencement Date occurs (the "Term",  which definition shall
include all renewals of the initial Term).  If the Premises are not delivered to
Tenant on the Commencement Date, then (a) Tenant's  obligation to pay Basic Rent
and  Additional  Rent (as defined in Section 3) shall be waived  until  Landlord
tenders  possession  of the  Premises to Tenant,  (b)  Landlord  shall not be in
default hereunder or be liable for damages therefor, and (c) Tenant shall accept
possession of the Premises when Landlord tenders  possession  thereof to Tenant.
Use and occupancy of the Premises by Tenant prior to the Commencement Date shall
be subject to all of the provisions of this Lease excepting only those requiring
the payment of Basic Rent.

3. Rent.

(a)......Basic Rent. "Basic Rent" (herein so called) shall be the following
 amounts for the following periods of time:


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

Time Period            Annual Basic Rent                    Monthly Basic Rent


Lease Years 1-2            $657,824.00                           $54,818.67

Lease Years 3-5            $945,622.00                           $78,801.83

Lease Years 6-8            $986,736.00                           $82,228.00

Lease Years 9-13          $1,068,964.00                          $89,080.33





<PAGE>



                                                                  33

         The term  "Lease  Year"  shall  mean any period of twelve  (12)  months
commencing  on  the  first  day of the  first  full  month  of the  Term  or any
anniversary of such date or, if fewer than twelve (12) months remain in the Term
after any such anniversary  period,  commencing on such anniversary date through
the last day of the Term.

                  (b)......Payment.  Tenant shall  timely pay to Landlord  Basic
Rent and all  additional  sums to be paid by Tenant to Landlord under this Lease
(collectively,  the "Rent"),  without  notice,  deduction or set off,  except as
otherwise  provided herein, at Landlord's  address provided for in this Lease or
as otherwise  specified by Landlord.  Basic Rent,  adjusted as herein  provided,
shall be payable monthly in advance,  and shall be accompanied by all applicable
state and local sales or use taxes. Basic Rent shall be payable on the first day
of each month beginning on the first day of the first full calendar month of the
Term.  The monthly Basic Rent for any partial month at the beginning of the Term
shall equal the product of 1/365 of the annual  Basic Rent in effect  during the
partial  month and the  number of days in the  partial  month from and after the
Commencement Date, and shall be due on the Commencement Date.

                  (c)......Operating Costs.

                           (1)......Tenant  shall pay, as "Additional Rent", the
         Operating  Costs  (defined  below).  Landlord  may  make a  good  faith
         estimate of the  Additional  Rent to be due by Tenant for any  calendar
         year or part thereof during the Term, and Tenant shall pay to Landlord,
         on the  Commencement  Date and on the first day of each calendar  month
         thereafter,  an amount equal to the estimated  Additional Rent for such
         calendar year or part thereof  divided by the number of months therein.
         From time to time,  but not more often  than  twice in any twelve  (12)
         month period, Landlord may estimate and re-estimate the Additional Rent
         to be due by  Tenant  and  deliver  a  detailed  line  item copy of the
         estimate or re-estimate to Tenant. Thereafter, the monthly installments
         of Additional Rent payable by Tenant shall be appropriately adjusted in
         accordance  with the  estimations  so that,  by the end of the calendar
         year in question,  Tenant shall have paid all of the Additional Rent as
         estimated by Landlord. Any amounts paid based on such an estimate shall
         be subject to adjustment as herein provided when actual Operating Costs
         are available for each calendar year.



<PAGE>


                           (2)......The  term  "Operating  Costs" shall mean all
         expenses and disbursements (subject to the limitations set forth below)
         that Landlord incurs in connection with the ownership,  operation,  and
         maintenance  of the Premises,  determined in accordance  with generally
         accepted   accounting   principles   ("GAAP")   consistently   applied,
         including,  but not  limited  to, the  following  costs:  (A) wages and
         salaries  (including  management fees) of all employees  engaged in the
         operation,  maintenance, and security of the Premises, including taxes,
         insurance and benefits relating thereto; (B) all supplies and materials
         used in the operation,  maintenance,  repair, replacement, and security
         of the Premises; (C) costs for improvements made to the Premises which,
         if capital in nature,  shall be amortized over the useful economic life
         of such  improvements  as  determined  by  Landlord  in its  reasonable
         discretion;  (D) cost of all  utilities,  except the cost of  utilities
         paid  directly by Tenant or  reimbursable  to Landlord by Tenant  other
         than  pursuant  to a  provision  similar  to this  Section  3.(c);  (E)
         insurance expenses; (F) repairs,  replacements, and general maintenance
         of  the  Premises;  and  (G)  service  or  maintenance  contracts  with
         independent  contractors  for  the  operation,   maintenance,   repair,
         replacement,   or  security  of  the   Premises   (including,   without
         limitation, alarm service, window cleaning, and elevator maintenance).

                  Operating  Costs  shall  not  include  costs  for (i)  repair,
         replacements  and general  maintenance paid by proceeds of insurance or
         by Tenant or other third parties; (ii) interest,  amortization or other
         payments  on  loans  to  Landlord;  (iii)  depreciation;  (iv)  leasing
         commissions;  (v) legal  expenses for  services,  other than those that
         benefit Tenant (e.g., tax disputes);  (vi) Taxes (defined below); (vii)
         federal  income taxes  imposed on or measured by the income of Landlord
         from the operation of the  Premises;  (viii) any cost or expense to the
         extent to which Landlord is paid or reimbursed (other than as a payment
         for Operating  Costs),  including but not  necessarily  limited to, (1)
         work or service  performed  for any tenant  (including  Tenant) at such
         tenant's costs,  (2) the cost of any item for which Landlord is paid or
         reimbursed by insurance  warranties,  service  contracts,  condemnation
         proceeds or otherwise,  (3) charges  (including  applicable  taxes) for
         electricity,  water and other  utilities for which Landlord is entitled
         to  reimbursement  pursuant to other  provisions of this Lease, and (4)
         the cost of any HVAC,  janitorial or other services provided to tenants
         on an extra-cost  basis after regular  business hours as defined in the
         Lease;  (ix) the cost of  correcting  initial  defects  in the  design,
         construction or equipment of the Building;  (x) salaries and bonuses of
         officers  and  executives  of  Landlord;  (xi)  any  cost  included  in
         Operating  Costs  representing  an  amount  paid  to  a  person,  firm,
         corporation  or other entity  related to Landlord which is in excess of
         the amount  which would have been paid on an arms  length  basis in the
         absence of such relationship;  (xii) any capital cost necessary to cure
         any  violation of any law,  ordinance or  regulation  applicable to the
         Building  existing  as of the  Commencement  Date or to  remediate  any
         environmental condition (existing as of the date of the Lease) provided
         Tenant in no way  exacerbates  any such  condition;  (xiii) the cost of
         acquiring  sculptures,  paintings and other objects of art in excess of
         $2,000 per item; and (xiv) the cost of advertising or promotion for the
         Building.



<PAGE>


                           (3)......Tenant  shall  also pay the  Taxes  for each
         year and partial  year falling  within the Term,  in the same manner as
         provided  above for  Additional  Rent with regard to  Operating  Costs.
         "Taxes" shall mean taxes, assessments, and governmental charges whether
         federal,  state,  county or  municipal,  and whether  they be by taxing
         districts or authorities  presently  taxing or by others,  subsequently
         created or otherwise,  and any other taxes and assessments attributable
         to the Building (or its operation),  excluding,  however, penalties and
         interest  thereon and federal and state taxes on income (if the present
         method of taxation  changes so that in lieu of the whole or any part of
         any Taxes,  there is levied on Landlord a capital  tax  directly on the
         rents  received  therefrom or a franchise  tax,  assessment,  or charge
         based, in whole or in part, upon such rents for the Building,  then all
         such  taxes,  assessments,  or charges,  or the part  thereof so based,
         shall be deemed to be included  within the term  "Taxes"  for  purposes
         hereof).  Tenant  shall,  at its sole cost and  expense  and upon prior
         written notice to Landlord,  have the right to seek an abatement of the
         Taxes provided that Tenant shall promptly  provide Landlord with copies
         of all papers filed with various authorities in connection with seeking
         such an  abatement  and with copies of all papers  received  from other
         parties  relating to any such abatement.  Taxes shall include the costs
         of  consultants  retained  in an  effort  to lower  taxes and all costs
         incurred  in  disputing  any  taxes  or in  seeking  to  lower  the tax
         valuation of the Building.  The following  items shall be excluded from
         Taxes:  (A) inheritance  taxes; (B) gift taxes; (C) transfer taxes; (D)
         franchise  taxes; (E) excise taxes; (F) income taxes; (G) profit taxes;
         and (H) late payment  charges and penalties  provided  Tenant is not in
         default of any of its payment obligations under this Lease.  Subject to
         the provisions of the next succeeding sentence, any real estate related
         betterment assessments shall be payable over the longest period of time
         permitted by law. If Landlord elects to pay any such assessments over a
         shorter period of time, Tenant shall only be required to pay during any
         given  period of time that portion of any given  assessment  that would
         have  been  required  to be paid  during  such  period  of time if such
         assessment  had been paid over the longest  period of time permitted by
         law.

                           (4)......By April 1 of each calendar year, or as soon
         thereafter as practicable, Landlord shall furnish to Tenant a statement
         of  Operating  Costs for the  previous  year,  adjusted  as provided in
         Section  3.(c)(6),  and  of  the  Taxes  for  the  previous  year  (the
         "Operating  Costs and Tax  Statement").  If the Operating Costs and Tax
         Statement  reveals that Tenant paid more for  Operating  Costs than the
         actual amount for the year for which such  statement  was prepared,  or
         more than its actual share of Taxes for such year,  then Landlord shall
         promptly  credit or  reimburse  Tenant for such  excess;  likewise,  if
         Tenant  paid less than the actual  Additional  Rent or Taxes due,  then
         Tenant shall promptly pay Landlord such  deficiency  within thirty (30)
         days after receiving written notice from Landlord of the amount of such
         deficiency.  Any such  Operating  Costs and Tax Statement  furnished by
         Landlord  shall be binding and  conclusive  upon Tenant  unless  Tenant
         shall notify  Landlord  that Tenant  disputes the  correctness  of such
         Operating Costs and Tax Statement  within one hundred eighty (180) days
         after the  submission  thereof by  Landlord.  If Tenant  disputes  such
         Operating  Cost and Tax  Statement as  aforesaid,  and Tenant is not in
         default of its monetary obligations under this Lease, Tenant shall have
         the right to audit  Landlord's  books used to determine  said Operating
         Cost and Tax  Statement  within  one  hundred  eighty  (180) days after
         submission  thereof  by  Landlord,  which  right  Tenant  agrees not to
         exercise more than once annually. Access to said Operating Cost and Tax
         Statement  books shall be provided  within thirty (30) days of Tenant's
         request.  Any information obtained by Tenant pursuant to the provisions
         of this Section 3(d)(4) shall be treated as  confidential.  If any such
         audit discloses Tenant paid in excess of Tenant's  proportionate  share
         of Operating Costs or Tax Escalation, Landlord shall promptly reimburse
         such excess to Tenant  within  thirty (30) days after  Tenant's  demand
         therefor.  Landlord  shall  maintain  its books used to  determine  the
         Operating Cost and Tax Statement in a manner  consistent with reputable
         professional  standards  used  to  maintain  the  books  of  comparable
         properties.



<PAGE>


         4. Delinquent Payment;  Handling Charges. All payments past due by five
(5) days beyond the due date  required of Tenant  hereunder  shall bear interest
from the fifth (5th) day beyond the date due until paid at the lesser of 18% per
annum (the "Interest Rate") or the maximum lawful rate of interest. In no event,
however,  shall the charges  permitted under this Section 4 or elsewhere in this
Lease,  to the extent they are considered to be interest  under law,  exceed the
maximum lawful rate of interest.

         5.  Security  Deposit.  Contemporaneously  with the  execution  of this
Lease, Tenant shall pay to Landlord $160,000.00 (the "Security Deposit"),  which
shall be held by  Landlord to secure  Tenant's  performance  of its  obligations
under this Lease.  The Security  Deposit is not an advance  payment of Rent or a
measure or limit of  Landlord's  damages  upon an Event of Default  (defined  in
Section 16).  Landlord may, from time to time and without prejudice to any other
remedy,  use all or a part of the  Security  Deposit to perform  any  obligation
Tenant  fails  to  perform  hereunder.  Following  any such  application  of the
Security  Deposit,  Tenant shall pay to Landlord on demand the amount so applied
in order to restore the Security Deposit to its original  amount.  Provided that
Tenant has performed all of its obligations  hereunder,  Landlord shall,  within
thirty  (30) days  after the Term  ends,  return to Tenant  the  portion  of the
Security  Deposit  which was not applied to satisfy  Tenant's  obligations.  The
Security  deposit may be commingled  with other funds,  and no interest shall be
paid  thereon.  If  Landlord  transfers  its  interest in the  Premises  and the
transferee  assumes  Landlord's  obligations under this Lease, then Landlord may
assign the Security Deposit to the transferee and Landlord thereafter shall have
no further liability for the return of the Security Deposit.



<PAGE>


         In lieu of a cash Security Deposit,  simultaneously  with the execution
and delivery of this Lease,  Tenant may deliver to Landlord an  irrevocable  and
unconditional standby letter of credit made payable to Landlord,  its successors
and assigns,  in the sum of $160,000.00 (the "Letter of Credit"),  substantially
in the form of the sample  letter of credit  attached  hereto as Exhibit F or in
such other form as is reasonably acceptable to Landlord,  which shall secure the
performance by Tenant of all  obligations on the part of Tenant  hereunder.  The
issuer of the Letter of Credit  shall be a banking  institution  with at least a
rating of A and otherwise reasonably  acceptable to Landlord.  Although Landlord
shall  only  have the  right to draw  under  the  Letter  of Credit as set forth
herein,  under  the  terms  of the  Letter  of  Credit,  the sole  condition  to
Landlord's  draw upon the Letter of Credit  shall be  presentment  to the issuer
thereof, prior to or on the expiration date, of a demand for payment. The Letter
of Credit shall be self-renewing from year to year during the Term of this Lease
so as to expire no earlier than thirty (30) days following the Lease  expiration
date and shall contain such other  customary  terms as Landlord  requires in its
reasonable discretion.  It is agreed: (i) that the Letter of Credit may be drawn
upon to cure any Event of Default that may exist, without prejudice to any other
remedy  or  remedies  which  Landlord  may  have on  account  thereof,  and upon
Landlord's demand,  Tenant shall reimburse the issuer for the amount so drawn so
that the Letter of Credit will be restored to its original amount;  (ii) subject
to the  provisions of clause (iv) below,  that the Letter of Credit may be drawn
upon if the Letter of Credit has not been extended or renewed without  amendment
at least forty-five (45) days prior to any then-current expiration date thereof;
(iii) that if the rating of the issuer of the Letter of Credit at any time drops
below A, then, within sixty (60) days of Landlord's demand, Tenant shall replace
the  Letter  of Credit  with  another  Letter  of  Credit  in a form  reasonably
acceptable  to  Landlord  and with an issuer  with a rating of at least an A and
otherwise reasonably  acceptable to Landlord;  Landlord may draw on the existing
Letter of Credit if, after  Landlord  requests that Tenant replace the Letter of
Credit as aforesaid, Landlord is not provided with a substitute Letter of Credit
in a form,  and from an issuer,  satisfactory  to Landlord as provided  above at
least fifteen (15) days prior to the then-current  expiration date of the Letter
of Credit; (iv) if at any time, but in any event, at least sixty (60) days prior
to the expiration of the Letter of Credit, Tenant may seek Landlord's consent to
switch  issuers of the Letter of Credit  provided the  prospective  issuer has a
rating of at least an A and is otherwise  reasonably  acceptable to Landlord and
the new  form of  Letter  of  Credit  satisfies  the  requirements  of  Landlord
hereunder and is otherwise reasonably acceptable to Landlord;  Landlord may draw
on the existing Letter of Credit if, after Tenant requests Landlord's consent to
switch issuers as aforesaid,  Landlord is not provided with a substitute  Letter
of Credit in a form,  and from an issuer,  satisfactory  to Landlord in its sole
and absolute  discretion at least forty-five (45) days prior to the then-current
expiration  date of the  Letter of  Credit;  (v) that  should  the  Premises  be
conveyed  by  Landlord,  the Letter of Credit or any  portion  thereof  shall be
assigned to Landlord's grantee, and if the same be assigned as aforesaid, Tenant
hereby  releases  Landlord from any and all liability with respect to the Letter
of Credit  and its  application  or return,  and  Tenant  agrees to look to such
grantee for such application or return, provided such grantee assumes Landlord's
obligations  under  this Lease  (including  this  Section  5); and (vi) that the
Letter of Credit  shall be  returned to Tenant upon the later of (a) thirty (30)
days after the  expiration of the Term or any renewal or extension  thereof,  or
(b) the date Tenant has vacated the Premises and surrendered  possession thereof
to Landlord at the  expiration of the Term or any extension  thereof as provided
herein and has paid Landlord all sums due and owing under this Lease.

         If Tenant  initially  provides  Landlord with a cash Security  Deposit,
Tenant  may  replace  such  cash  Security  Deposit  with a Letter  of Credit in
accordance  with the  provisions of the  preceding  paragraph.  Upon  Landlord's
receipt  of a Letter  of Credit  satisfying  the  terms  and  conditions  of the
preceding paragraph, Landlord shall promptly return the cash Security Deposit to
Tenant.

         For the  purposes  of this  Section  5, a rating  of at least A (or its
equivalent)  shall  mean  that  such  issuer  has a rating of at least A (or its
equivalent)  from two (2) of the  following  four  (4)  rating  agencies:  Fitch
Investors Service,  Moody's Investor Service,  Standard & Poor's Corporation and
Duff & Phelps.

         6. Landlord's Obligations.



<PAGE>


                  (a)......Services.   Landlord  shall  furnish  to  Tenant  the
following  services (the cost of which  services  shall be considered  Operating
Costs):  (1) hot and cold water at bathroom  sinks  provided  for general use of
tenants of the  Building;  (2)  heated  and  refrigerated  air  conditioning  as
appropriate,  at such  temperatures  and in such  amounts  as are  standard  for
comparable  buildings in the vicinity of the Building;  (3)  janitorial  service
(which janitorial  service shall include service to the interior and exterior of
the  Building  and the  Premises  and shall  include  the  services  customarily
provided  to  comparable   properties  by  reputable   professional   management
companies, including, without limitation,  maintenance,  repairs and replacement
of (u) the  parking  area  associated  with  the  Building  and  located  on the
Premises,  (v) all  grass,  shrubbery  and  other  landscape  treatments  on the
Premises,  (w) the exterior of the Building (including painting),  (x) sprinkler
systems and sewage lines, and (y) any other  maintenance,  repair or replacement
items normally associated with the foregoing) to the Premises on weekdays, other
than the  holidays  enumerated  on  Exhibit  I  attached  hereto  (collectively,
"Building  Holidays"),  for  Building-standard  installations  and  such  window
washing as may from time to time be reasonably  required but not less than twice
a year;  (4)  elevators  for ingress  and egress to the floors of the  Building,
provided that Landlord may  reasonably  limit the number of operating  elevators
during non-business hours and holidays; and (5) electrical current during normal
business hours for equipment that does not require more than 110 volts and whose
electrical energy  consumption does not exceed normal office usage. While Tenant
is the sole occupant of the Building,  Tenant may, with Landlord's prior written
consent  (which  consent  shall  not  be  unreasonably   withheld  or  delayed),
substitute at Tenant's expense any of the providers of the services described in
this  Section  6.(a) with  reputable,  licensed  third party  service  providers
located in the area in which the Building is located; provided,  however, Tenant
shall  provide  Landlord  with  copies of all  contracts  with any such  service
provider  and  said  contracts  shall  be  in  form  and  substance   reasonably
satisfactory to Landlord. If, in accordance with the provisions of the preceding
sentence,  Tenant engages (at its own cost) providers for all of the services to
be provided by Landlord under this Section 6.(a), the management fee included in
Operating  Costs shall be reduced to the greater of (i)  $1,300.00  per month or
(ii) one and  one-quarter  percent  (1 1/4%) of the gross  revenues  derived  by
Landlord  from the  Premises.  If Tenant  engages  providers of the services set
forth in this Section 6.(a) as aforesaid and any such services are provided,  in
Landlord's   reasonable   discretion,   at  an  unsatisfactory  level  as  would
customarily  be provided  to  comparable  buildings,  Landlord  may,  upon prior
written notice to Tenant,  elect to provide such services and the management fee
shall no longer be reduced.  If Landlord is providing  the services set forth in
this Section 6.(a) and Tenant  desires any of the services  specified in Section
6.(a)(2): (A) at any time other than between 8:00 a.m. and 6:00 p.m. on weekdays
(excluding Building Holidays), or (B) on Saturday,  Sunday or Building Holidays,
then such  services  shall be supplied  to Tenant  upon the  written  request of
Tenant delivered to Landlord before 3:00 p.m. on the business day preceding such
extra usage,  and Tenant shall pay to Landlord the cost of such services  within
ten (10) days after  Landlord has delivered to Tenant an invoice  therefor.  The
costs incurred by Landlord in providing  after-hour HVAC service to Tenant shall
include costs for electricity,  water, sewage, water treatment, labor, metering,
filtering,  and maintenance  reasonably  allocated by Landlord to providing such
service.

         Landlord  and  Tenant  hereby  acknowledge  and agree  that,  as of the
Commencement  Date,  Tenant shall engage  providers of the services set forth in
this  Section  6.(a).  However,  upon sixty (60) days  prior  written  notice to
Landlord, Tenant may elect to have Landlord provide such services.



<PAGE>


         If,  during  the last  two (2)  years  of the  Term  (inclusive  of the
five-year extension if Tenant elects to exercise the same in accordance with the
provisions of Exhibit G) and during a time when Tenant is engaging  providers of
the services set forth in this Section  6.(a),  Tenant  elects to make a capital
improvement to the Base Building (as hereinafter  defined)  because that portion
of the Base Building fails to operate (as opposed to operates less efficiently),
Landlord agrees to pay the unamortized  cost of any such capital  improvement on
the following terms and conditions  provided such failure is not a result of any
act, omission,  fault,  negligence or neglect of Tenant, its agents,  employees,
invitees or contractors: (i) Landlord and Tenant agree in writing on the cost of
any such  capital  improvement  and the useful life over which any such  capital
improvement  shall be amortized  prior to the  installation  of any such capital
improvement  (ii) to the extent  capital  improvements  are  devoted to Building
systems, the Building systems shall not be in excess of standard building design
for comparable  buildings in the 495 North market;  and (iii) Landlord agrees to
pay the unamortized cost of any such capital improvement as previously agreed to
in  writing  by the  parties  within  sixty  (60)  days  after  the later of the
expiration  of  this  Lease  or the  date  Tenant  surrenders  the  Premises  in
accordance  with this Lease provided  Tenant is not in default  hereunder,  this
Lease  does not  terminate  prior to the stated  expiration  date and Tenant has
maintained  and repaired any such capital  improvement  in  accordance  with the
provisions of this Lease.

         For the  purposes of this  Lease,  the "Base  Building"  shall mean the
roof,  foundation,  structural columns and Building systems to the extent any of
the foregoing have not been altered or improved by Tenant in any manner.

                  (b)......Landlord's  Maintenance  Obligations.  This  Lease is
intended to be a net lease; accordingly,  Landlord's maintenance obligations are
limited to the repair,  maintenance  and  replacement of the Building's roof and
the repair, maintenance and replacement of the foundation and structural members
of  exterior  walls  (the  "Building's   Structure");   Landlord  shall  not  be
responsible  for (1) any such work until  Tenant  notifies  Landlord of the need
therefor in writing, (2) for alterations to the Building's Structure required by
applicable law because of Tenant's use of the Premises (which  alterations shall
be Tenant's responsibility),  (3) any such work caused by Tenant's negligence or
its  failure  to comply  with the  provisions  of this  Lease,  or (4) any costs
incurred by Landlord in connection  with the repair and maintenance of the roof,
which repair and  maintenance  costs shall be considered  an Operating  Cost and
paid by Tenant in accordance with Section 3 above. The Building's Structure does
not include skylights,  windows, glass or plate glass, doors, special fronts, or
office entries,  all which shall be maintained by Tenant.  Landlord's  liability
for any  defects,  repairs,  replacements  or  maintenance  for  which  Landlord
specifically is responsible for under this Lease shall be limited to the cost of
performing the work.



<PAGE>


                  (c)......Excess Utility Use. Landlord shall not be required to
furnish  electrical current for equipment that requires more than the electrical
capacity  currently  provided in the  Building  (the "Base  Building  Electrical
Capacity").  If Tenant's  requirements for or consumption of electricity  exceed
the Base Building Electrical Capacity, Landlord shall, at Tenant's expense, make
reasonable efforts to supply such service through the then-existing  feeders and
risers  serving the Building,  and Tenant shall pay to Landlord the cost of such
service  within ten (10) days after  Landlord has delivered to Tenant an invoice
therefor.  Landlord may determine the amount of such additional  consumption and
potential  consumption by any verifiable  method,  including  installation  of a
separate meter in the Premises installed,  maintained,  and read by Landlord, at
Tenant's expense.  Tenant shall not install any electrical  equipment  requiring
special  wiring or requiring  voltage in excess of the Base Building  Electrical
Capacity unless  approved in advance by Landlord.  The use of electricity in the
Premises  shall not exceed the  capacity  of  existing  feeders and risers to or
wiring in the Building.  Any risers or wiring  required to meet Tenant's  excess
electrical  requirements  shall, upon Tenant's written request,  be installed by
Landlord,  at Tenant's cost, if, in Landlord's judgment,  the same are necessary
and shall not cause permanent  damage to the Building or the Premises,  cause or
create a dangerous  or hazardous  condition,  entail  excessive or  unreasonable
alterations, repairs, or expenses, or interfere with or disturb other tenants of
the Building.  If Tenant uses machines or equipment in the Building which affect
the temperature otherwise maintained by the air conditioning system or otherwise
overload any utility,  Landlord may install  supplemental air conditioning units
or other supplemental equipment in the Building, and the cost thereof, including
the cost of  installation,  operation,  use, and  maintenance,  shall be paid by
Tenant to Landlord  within ten (10) days after  Landlord has delivered to Tenant
an invoice therefor.

                  (d)......Restoration  of Services;  Abatement.  Landlord shall
use  reasonable  efforts to restore  any  service  required  of it that  becomes
unavailable;  however,  such unavailability shall not render Landlord liable for
any damages caused thereby, be a constructive  eviction of Tenant,  constitute a
breach of any implied  warranty,  or,  except as provided in the next  sentence,
entitle Tenant to any abatement of Tenant's obligations hereunder.  If, however,
Tenant is prevented  from using the Premises for ten (10)  consecutive  business
days because of the  unavailability  of any such service,  then Tenant shall, as
its  exclusive  remedy be entitled to a  reasonable  abatement  of Rent for each
consecutive  day (after  such ten (10) day period)  that Tenant is so  prevented
from using the Premises.

                  (e)......Taxes.  Provided  Tenant is not in  default of any of
its monetary obligations under this Lease,  Landlord shall pay promptly when due
to the taxing authority having jurisdiction all taxes, rates, duties, levies and
assessments whatsoever,  whether municipal, state, Federal or otherwise, levied,
imposed or assessed  against the Building or upon Landlord in respect thereof or
from time to time  levied,  imposed or assessed  in the future in lieu  thereof,
including  those levied,  imposed or assessed for  education,  schools and local
improvements.

                  (f)......Landlord's  Insurance.  Landlord shall carry 
 throughout  the Term of this Lease fire and extended  coverage
                           --------------------- 
insurance on the Building for the full replacement value.

         7.       Improvements; Alterations; Repairs; Maintenance.



<PAGE>


                  (a)......Improvements;   Alterations.   Improvements   to  the
Premises  shall be installed at Tenant's  expense only in accordance  with plans
and  specifications  which have been  previously  submitted  to and  approved in
writing by Landlord.  No alterations or physical additions in or to the Premises
may be made  without  Landlord's  prior  written  consent,  which  shall  not be
unreasonably withheld or delayed;  however, Landlord may withhold its consent to
any  alteration  or addition that would affect the  Building's  structure or its
HVAC,  plumbing,   electrical,   or  mechanical  systems.   Notwithstanding  the
foregoing,  Tenant  may  from  time  to  time  make  alterations,  additions  or
improvements  to the  Premises,  without  the  consent of  Landlord  and without
Landlord's  approval of plans,  provided:  (i) the cost thereof shall not exceed
Fifty  Thousand  Dollars  ($50,000.00)  in  the  aggregate  in  any  consecutive
twelve-month   period;   (ii)  Tenant  shall,   prior  to  commencing  any  such
alterations,  additions  and/or  improvements  in  the  Premises  in  connection
therewith,  furnish Landlord with a complete set of plans and specifications for
any such  alterations,  additions and/or  improvements;  (iii) such alterations,
additions  and/or  improvements  shall not involve or affect the exterior or the
structure  of the  Building  or any of the  mechanical,  electrical  or plumbing
systems of the Building;  and (iv) Tenant shall comply with all  requirements of
this Lease with respect to such alterations, additions and/or improvements other
than obtaining the prior approval of Landlord. Tenant shall not paint or install
lighting or decorations,  signs, window or door lettering,  or advertising media
of any type on or about the Premises  which might affect the  appearance  of the
exterior of the  Building or any other  portion of the  Premises  other than the
interior of the Building  without the prior written  consent of Landlord,  which
shall not be unreasonably  withheld or delayed;  however,  Landlord may withhold
its  consent  to any such  painting  or  installation  which  would  affect  the
appearance  of the  exterior  of the  Building  or of any  common  areas  of the
Building.  All  alterations,  additions,  or  improvements  made in or upon  the
Premises  shall be  removed by Tenant  prior to the end of the Term (and  Tenant
shall repair all damage caused  thereby) if Landlord  conditioned its consent to
the initial installation of any such alterations, additions or improvements upon
such removal; otherwise, in the absence of such a removal condition with respect
to each and every  alteration,  addition or improvement,  all such  alterations,
additions or improvements  (excluding  moveable  partitions) shall remain on the
Premises at the end of the Term without compensation to Tenant. All alterations,
additions,  and  improvements  shall  be  constructed,  maintained,  and used by
Tenant,  at its risk and  expense,  in  accordance  with  all  Laws;  Landlord's
approval of the plans and specifications  therefor shall not be a representation
by Landlord that such alterations,  additions,  or improvements  comply with any
Law.



<PAGE>


                  (b)......Repairs;   Maintenance.  Tenant  shall  maintain  the
Premises in a clean safe, and operable  condition  consistent with the operation
of a first class  office  building,  and shall not permit or allow to remain any
waste or damage  to any  portion  of the  Premises.  If Tenant  elects to engage
providers for all services in accordance with Section 6.(a) above,  Tenant shall
enter  into  preventative   maintenance/service   contract(s)  with  maintenance
contractor(s) approved by Landlord for servicing the landscaping of the Premises
and all air conditioning, heating and ventilating equipment, elevators and other
equipment   located   within  or  serving   the   Premises.   All   preventative
maintenance/service   contracts  shall  be  in  form  and  substance  reasonably
satisfactory to Landlord and shall provide that the maintenance contractor shall
provide  Landlord with  quarterly  reports  respecting  the  maintenance  of the
subject  equipment.  Tenant  shall  provide  Landlord  with  copies  of all such
preventative maintenance/service contracts maintained by Tenant. Irrespective of
whether  or not  Tenant  elects  not to engage  providers  for all  services  in
accordance with Section 6.(a) above, Tenant shall repair or replace,  subject to
Landlord's  reasonable  direction and  supervision,  any  improvement  or system
installed by Tenant within the Premises and any damage to the Building caused by
Tenant,  Tenant's  transferees,  or their  respective  agents,  contractors,  or
invitees.  If Tenant fails to make such repairs or  replacements  within  thirty
(30) days (or such  shorter  period of time  required to prevent any damage from
occurring to the Premises)  after the  occurrence of such damage,  then Landlord
may make the same at Tenant's cost.

                  (c)......Performance  of  Work.  All  work  described  in this
Section  7  shall  be  performed  only  by  Landlord  or  by   contractors   and
subcontractors  reasonably  approved in writing by Landlord  and Tenant.  Tenant
shall cause all contractors and subcontractors to procure and maintain insurance
coverage  naming  Landlord as an additional  insured against such risks, in such
amounts,  and with such companies as Landlord may reasonably  require.  All such
work  shall  be  performed  in  accordance  with  all  Laws  and in a  good  and
workmanlike  manner so as not to  damage  the  Premises,  the  Building,  or the
components thereof.

         Tenant shall  provide the names,  addresses and copies of contracts for
all contractors, and upon completion of any work shall promptly furnish Landlord
with full and final waivers of lien  covering all labors and materials  included
in the work in question.

                  (d)......Mechanic's   Liens.   Tenant  shall  not  permit  any
mechanic's  liens to be filed  against the Premises or the Building for any work
performed,  materials furnished,  or obligation incurred by or at the request of
Tenant. If such a lien is filed,  then Tenant shall,  within ten (10) days after
Landlord has delivered  notice of the filing  thereof to Tenant,  either pay the
amount of the lien or  diligently  contest  such lien and  deliver to Landlord a
bond or other security reasonably  satisfactory to Landlord.  If Tenant fails to
timely take either such action,  then  Landlord may pay the lien claim,  and any
amounts so paid,  including  expenses and  interest,  shall be paid by Tenant to
Landlord within ten days after Landlord has invoiced Tenant therefor.

                  (e)......Utilities. Tenant shall obtain and pay for all water,
gas, electricity,  heat, telephone, sewer, sprinkler charges and other utilities
and  services  used  at  the  Premises,  together  with  all  taxes,  penalties,
surcharges,  and maintenance charges pertaining  thereto.  Landlord shall not be
liable for any interruption or failure of utility service to the Premises unless
caused by  Landlord's  gross  negligence.  To the  extent  Tenant is not  billed
directly  for any such  utilities,  any  amounts  payable  by Tenant  under this
Section  shall be due within ten (10) days after  Landlord has  invoiced  Tenant
therefor.

                  (f)......Floor  Load;  Heavy  Machinery.  (i) Tenant shall not
place a load upon any floor in the Building  exceeding the floor load per square
foot of area which such floor was  designed to carry or 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  and/or heavy equipment 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.



<PAGE>


                           (ii).....If such safe, machinery,  equipment, 
freight,  bulky matter or fixtures requires special handling,
Tenant agrees 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.

         8. Use. Tenant shall continuously  occupy and use the Premises only for
general  office,  research  and  development,  manufacturing,  training,  sales,
service and engineering use (the  "Permitted  Use"),  provided the Permitted Use
complies with all  applicable  laws,  and shall comply with all Laws relating to
the use, condition, access to, and occupancy of the Premises. The Premises shall
not be used  for any use  which  is  disreputable,  creates  extraordinary  fire
hazards,  or results in an  increased  rate of insurance  on the  Premises,  the
Building or its  contents,  or for the  storage of any  hazardous  materials  or
substances.  If,  because of a Tenant Party's acts, the rate of insurance on the
Building or its contents increases, then such acts shall be an Event of Default,
Tenant  shall  pay to  Landlord  the  amount of such  increase  on  demand,  and
acceptance  of such  payment  shall not waive any of  Landlord's  other  rights.
Tenant shall  conduct its business and control each other Tenant Party so as not
to create any nuisance or unreasonably interfere with Landlord in its management
of the Building.

         9.       Assignment and Subletting.



<PAGE>


                  (a)......Transfers;  Consent.  Tenant  shall not,  without the
prior written consent of Landlord, (1) assign,  transfer, or encumber this Lease
or any estate or interest  herein,  whether directly or by operation of law, (2)
permit any other entity to become Tenant hereunder by merger, consolidation,  or
other reorganization,  (3) if Tenant is an entity other than a corporation whose
stock is publicly traded, permit the transfer of an ownership interest in Tenant
so as to result in a change in the  current  control of  Tenant,  (4) sublet any
portion of the Premises,  (5) grant any license,  concession,  or other right of
occupancy of any portion of the Premises,  or (6) permit the use of the Premises
by any parties other than Tenant (any of the events  listed in Section  9.(a)(1)
through 9.(a)(6) being a "Transfer"). If Tenant requests Landlord's consent to a
Transfer,  then Tenant shall provide Landlord with a written  description of all
terms  and  conditions  of  the  proposed  Transfer,   copies  of  the  proposed
documentation, and the following information about the proposed transferee: name
and address; reasonably satisfactory information about its business and business
history; its proposed use of the Premises;  banking, financial, and other credit
information;  and general references  sufficient to enable Landlord to determine
the proposed  transferee's  creditworthiness  and character.  Landlord shall not
unreasonably  withhold or delay its consent to any  assignment  or subletting of
the Premises, provided that the proposed transferee (A) is creditworthy, (B) has
a good reputation in the business  community,  and (C) is not a person or entity
with whom  Landlord is  negotiating  to lease space in an  Affiliated  Building;
otherwise,   Landlord  may   withhold  its  consent  in  its  sole   discretion.
Concurrently  with  Tenant's  notice of any  request  for consent to a Transfer,
Tenant shall pay to Landlord a fee of $500.00 to defray  Landlord's  expenses in
reviewing  such request,  and Tenant shall also reimburse  Landlord  immediately
upon request for its  reasonable  attorneys'  fees incurred in  connection  with
considering  any request for  consent to a Transfer.  If Landlord  consents to a
proposed  Transfer,  then the proposed  transferee  shall  deliver to Landlord a
written agreement whereby it expressly assumes Tenant's  obligations  hereunder;
however,  any  transferee of less than all of the space in the Premises shall be
liable only for obligations under this Lease that are properly  allocable to the
space subject to the Transfer for the period of the Transfer.  No Transfer shall
release Tenant from its obligations  under this Lease, but rather Tenant and its
transferee shall be jointly and severally liable therefor. Landlord's consent to
any Transfer shall not waive Landlord's  rights as to any subsequent  Transfers.
If an Event of Default occurs while the Premises or any part thereof are subject
to a Transfer,  then Landlord,  in addition to its other  remedies,  may collect
directly from such  transferee  all rents  becoming due to Tenant and apply such
rents against Rent.  Tenant  authorizes its transferees to make payments of rent
directly to Landlord upon receipt of notice from Landlord to do so. Tenant shall
pay for the cost of any demising walls or other  improvements  necessitated by a
proposed  subletting  or  assignment.  Notwithstanding  any  provisions  of this
Section 9(a) to the contrary,  Tenant may assign or sublet,  without  Landlord's
prior  written  consent,  to any entity  into or with which  Tenant is merged or
consolidated  or to  which  all or  substantially  all of  Tenant's  assets  are
transferred  or to any entity which  controls or is  controlled  by Tenant or is
under common control with Tenant ("Affiliate of Tenant"),  provided that (i) the
assignee  agrees  directly  with  Landlord,   by  written   instrument  in  form
satisfactory to Landlord,  to be bound by all  obligations of Tenant  hereunder,
including,  without  limitation,  the covenant  against further  Transfer,  (ii)
Tenant provides Landlord with notice of and information (reasonably satisfactory
to Landlord)  regarding any such Affiliate of Tenant and such assignment to such
Affiliate of Tenant before the effective date thereof, (iii) Tenant shall remain
fully liable for all obligations of Tenant hereunder,  and (iv) the Affiliate of
Tenant has a net worth equal to or greater  than the greater of (A)  ninety-five
percent  (95%) of Tenant's  net worth as of the date  hereof or (B)  ninety-five
percent (95%) of Tenant's net worth at the time of the Transfer.

                  (b)......Cancellation.  Landlord may,  within thirty (30) days
after  submission  of  Tenant's  written  request for  Landlord's  consent to an
assignment or  subletting  (except for an assignment or sublease to an Affiliate
of Tenant),  cancel this Lease as to the portion of the Premises  proposed to be
sublet or assigned  as of the date the  proposed  Transfer  is to be  effective,
unless,  and  subject  to the  provisions  of the  succeeding  sentence,  Tenant
withdraws  its  request  for  Landlord's  consent  within  ten (10)  days  after
Landlord's  notice to Tenant of  Landlord's  cancellation  of this Lease as to a
portion  of such  Premises.  Tenant  shall only have the right to  withdraw  its
request for Landlord's  consent if it pertains to a sublease of a portion of the
Building or a sublease of the Premises for less than the  remainder of the Term.
If  Landlord  cancels  this Lease as to any  portion of the  Premises  (assuming
Tenant does not withdraw its request as aforesaid),  then this Lease shall cease
for such  portion of the  Premises  and Tenant  shall pay to  Landlord  all Rent
accrued  through the  cancellation  date relating to the portion of the Premises
covered by the proposed Transfer. Thereafter, Landlord may lease such portion of
the Premises to the  prospective  transferee  (or to any other  person)  without
liability to Tenant.



<PAGE>


                  (c)......Additional   Compensation.   Tenant   shall   pay  to
Landlord,  immediately upon receipt thereof,  the excess of (1) all compensation
received by Tenant for a Transfer less the costs  reasonably  incurred by Tenant
with  unaffiliated  third  parties  in  connection  with  such  Transfer  (i.e.,
brokerage  commissions,  tenant  finish  work,  and the like)  over (2) the Rent
allocable to the portion of the Premises covered thereby.

         10.      Insurance; Waivers; Subrogation; Indemnity.

                  (a)......Insurance.  Tenant shall maintain throughout the Term
the following insurance policies:  (1) commercial general liability insurance in
amounts of $5,000,000  per occurrence or such other amounts as Landlord may from
time to time reasonably require,  insuring Tenant,  Landlord,  Landlord's agents
and their respective  affiliates against all liability for injury to or death of
a person or persons or damage to property  arising from the use and occupancy of
the  Premises,  (2) insurance  covering the full value of Tenant's  property and
improvements, and other property (including property of others) in the Premises,
(3)  contractual  liability  insurance  sufficient to cover  Tenant's  indemnity
obligations  hereunder,  (4) worker's compensation  insurance,  and (5) business
interruption  insurance.  Tenant's  insurance shall provide primary  coverage to
Landlord  when any  policy  issued to  Landlord  provides  duplicate  or similar
coverage,  and in  such  circumstance  Landlord's  policy  will be  excess  over
Tenant's policy. Tenant shall furnish to Landlord certificates of such insurance
and such other  evidence  satisfactory  to  Landlord of the  maintenance  of all
insurance  coverages  required  hereunder,  and  Tenant  shall  obtain a written
obligation  on the part of each  insurance  company to notify  Landlord at least
thirty (30) days before  cancellation or a material change of any such insurance
policies. All such insurance policies shall be in form, and issued by companies,
reasonably satisfactory to Landlord.

                  (b)......Waiver  of Negligence;  No Subrogation.  Landlord and
Tenant each  waives any claim it might have  against the other for any injury to
or death of any person or persons or damage to or theft,  destruction,  loss, or
loss of use of any  property  (a  "Loss"),  to the  extent  the same is  insured
against  under any  insurance  policy that covers the  Building,  the  Premises,
Landlord's or Tenant's fixtures, personal property,  leasehold improvements,  or
business,  or, in the case of Tenant's waiver, is required to be insured against
under the terms hereof,  regardless of whether the negligence of the other party
caused such Loss;  however,  Landlord's  waiver shall not include any deductible
amounts on insurance  policies  carried by Landlord.  Each party shall cause its
insurance  carrier to endorse all  applicable  policies  waiving  the  carrier's
rights of recovery under subrogation or otherwise against the other party.

                  (c)......Indemnity.  Subject to Section  10.(b),  Tenant shall
defend, indemnify, and hold harmless Landlord and its representatives and agents
from and against  all claims,  demands,  liabilities,  causes of action,  suits,
judgments,  damages,  and expenses (including  attorneys' fees) arising from (1)
any Loss  arising  from any  occurrence  on the  Premises  (other  than any Loss
arising out of a breach of Tenant's  obligations  under  Section  24.(u),  which
shall be subject to the  indemnity in such  section) or (2) Tenant's  failure to
perform its obligations under this Lease, unless caused solely by the negligence
or fault of Landlord or its  agents.  This  indemnity  provision  shall  survive
termination  or expiration of this Lease.  If any  proceeding is filed for which
indemnity is required hereunder, Tenant agrees, upon request therefor, to defend
the  indemnified  party in such  proceeding at its sole cost  utilizing  counsel
satisfactory to the indemnified party.


<PAGE>


                  (d)......Landlord's   Indemnity.  Subject  to  Section  10(b),
Landlord shall defend,  indemnify, and hold harmless Tenant from and against all
claims,  demands,  liabilities,  causes of action, suits, judgments and expenses
(including  attorneys'  fees) for any Loss  arising from any  occurrence  at the
Premises caused or materially  contributed to by Landlord's  gross negligence in
acting or failing to act,  and which Loss was not  contributed  to in any way by
Tenant's  actions or omissions.  This indemnity  shall survive the expiration or
termination of this Lease.

         11.      Subordination; Attornment; Notice to Landlord's Mortgagee.

                  (a)......Subordination. This Lease shall be subordinate to any
deed of trust,  mortgage,  or other  security  instrument,  or any ground lease,
master  lease,  or  primary  lease (any such  security  instrument  or lease,  a
"Mortgage"),  that now or hereafter  covers all or any part of the Premises (the
mortgagee under any such mortgage or the lessor under any such lease is referred
to herein as a "Landlord's  Mortgagee").  Any Landlord's Mortgagee may elect, at
any time,  unilaterally,  to make this Lease  superior to its  mortgage,  ground
lease,  or other  interest in the  Premises by so  notifying  Tenant in writing.
Tenant shall execute  agreements  confirming the subordination or superiority of
this Lease to any Mortgage upon Landlord or  Landlord's  Mortgagee's  reasonable
request.

                  (b)......Attornment.   Tenant   shall   attorn  to  any  party
succeeding  to  Landlord's  interest  in  the  Premises,  whether  by  purchase,
foreclosure,  deed in lieu of foreclosure,  power of sale, termination of lease,
or  otherwise,  upon such party's  request,  and shall  execute such  agreements
confirming such attornment as such party may reasonably request.

                  (c)......Notice to Landlord's Mortgagee. Tenant shall not seek
to  enforce  any  remedy  it may have for any  default  on the part of  Landlord
without first giving written notice by certified mail, return receipt requested,
specifying the default in reasonable  detail, to any Landlord's  Mortgagee whose
address has been given to Tenant,  and  affording  such  Landlord's  Mortgagee a
reasonable opportunity to perform Landlord's obligations hereunder.



<PAGE>


                  (d)......Landlord's   Mortgagee's  Protection  Provisions.  If
Landlord's Mortgagee shall succeed to the interest of Landlord under this Lease,
Landlord's  Mortgagee  shall not be: (1) liable for any act or  omission  of any
prior lessor (including  Landlord);  (2) bound by any rent or additional rent or
advance rent which Tenant might have paid for more than the current month to any
prior lessor (including Landlord), and all such rent shall remain due and owing,
notwithstanding  such  advance  payment;  (3) bound by any  security  or advance
rental  deposit made by Tenant which is not delivered or paid over to Landlord's
Mortgagee  and with  respect to which  Tenant  shall look solely to Landlord for
refund or reimbursement; (4) bound by any termination, amendment or modification
of this Lease made without Landlord's  Mortgagee's consent and written approval,
except for those terminations, amendments and modifications permitted to be made
by Landlord without Landlord's  Mortgagee's consent pursuant to the terms of the
loan documents  between  Landlord and Landlord's  Mortgagee;  (5) subject to the
defenses which Tenant might have against any prior lessor (including  Landlord);
and (6) subject to the offsets  which Tenant might have against any prior lessor
(including  Landlord)  except for those offset  rights  which (A) are  expressly
provided in this Lease,  (B) relate to periods of time following the acquisition
of the Premises by  Landlord's  Mortgagee,  and (C) Tenant has provided  written
notice to Landlord's  Mortgagee and provided  Landlord's  Mortgagee a reasonable
opportunity  to cure the event  giving  rise to such  offset  event.  Landlord's
Mortgagee  shall have no  liability or  responsibility  under or pursuant to the
terms of this  Lease or  otherwise  after it  ceases to own an  interest  in the
Premises.  Nothing  in this  Lease  shall be  construed  to  require  Landlord's
Mortgagee to see to the  application  of the proceeds of any loan,  and Tenant's
agreements set forth herein shall not be impaired on account of any modification
of the documents evidencing and securing any loan.

                  (e)......Subordination,    Non-Disturbance    and   Attornment
Agreement.  Simultaneously  upon Tenant's execution of this Lease,  Tenant shall
execute a Subordination,  Non-Disturbance  and Attornment  Agreement in the form
attached   hereto  as  Exhibit  J.  Landlord   shall  return  a  fully  executed
Subordination,  Non-Disturbance  and  Attornment  Agreement in the form attached
hereto  as  Exhibit  J from  the  Lender  named  therein  to  Tenant  as soon as
reasonably possible. Landlord shall use reasonable efforts to obtain a so-called
"nondisturbance agreement" from any further Landlord's Mortgagee.

         12.  Rules and  Regulations.  Tenant  shall  comply  with the rules and
regulations  of the Building  which are attached  hereto as Exhibit C.  Landlord
may, from time to time, change such rules and regulations for the safety,  care,
or  cleanliness  of the  Building  and related  facilities,  provided  that such
changes will not  unreasonably  interfere  with  Tenant's  use of the  Premises.
Tenant shall be responsible  for the compliance  with such rules and regulations
by each Tenant Party.

         13.      Condemnation.

                  (a)......Total Taking.  If the entire  Building or Premises 
are taken by right of eminent  domain or conveyed in lieu
                           ------------
thereof (a "Taking"), this Lease shall terminate as of the date of the Taking.
            ------ 

                  (b)......Partial  Taking - Tenant's Rights. If any part of the
Building  becomes  subject to a Taking and such Taking will prevent  Tenant from
conducting  its business in the Premises in a manner  reasonably  comparable  to
that  conducted  immediately  before  such  Taking for a period of more than one
hundred  eighty (180) days,  then Tenant may terminate this Lease as of the date
of such  Taking by giving  written  notice to Landlord  within  thirty (30) days
after the Taking,  and Rent shall be  apportioned as of the date of such Taking.
If  Tenant  does not  terminate  this  Lease,  then  Rent  shall be  abated on a
reasonable basis as to that portion of the Premises rendered untenantable by the
Taking.



<PAGE>


                  (c)......Partial  Taking - Landlord's  Rights. If any material
portion,  but less than all, of the Building becomes subject to a Taking,  or if
Landlord is required to pay at least $50,000.00 of any of the proceeds  received
for a Taking to a Landlord's  Mortgagee,  then Landlord may terminate this Lease
by  delivering  written  notice  thereof to Tenant within thirty (30) days after
such Taking,  and Rent shall be  apportioned  as of the date of such Taking.  If
Landlord does not so terminate this Lease, then this Lease will continue, but if
any portion of the Premises has been taken,  Rent shall abate as provided in the
last sentence of Section 13.(b). For the purposes of this Section 13 and Section
14, the term "material  portion" shall be deemed to mean at least twenty percent
(20%) of the rentable square feet of the Building.

                  (d)......Award.  If any Taking  occurs,  then  Landlord  shall
receive  the  entire  award or  other  compensation  for the  land on which  the
Building is situated, the Building, and other improvements taken, and Tenant may
separately  pursue a claim (to the extent it will not reduce  Landlord's  award)
against the condemnor for the value of Tenant's  personal  property which Tenant
is entitled to remove under this Lease,  moving  costs,  loss of  business,  and
other claims it may have.

         14.      Fire or Other Casualty.

                  (a)......Repair  Estimate. If the Premises or the Building are
damaged by fire or other casualty (a "Casualty"), Landlord shall, within 90 days
after  such  Casualty,  deliver  to Tenant a good faith  estimate  (the  "Damage
Notice") of the time needed to repair the damage caused by such Casualty.

                  (b)......Landlord's and Tenant's Rights. If a material portion
of the  Building  is damaged by  Casualty  such that  Tenant is  prevented  from
conducting  its business in the Premises in a manner  reasonably  comparable  to
that  conducted   immediately  before  such  Casualty  and  Landlord  reasonably
estimates that the damage caused thereby cannot be repaired  within fifteen (15)
months  after the Casualty (as such period may be extended by the number of days
lost as a result of force majeure  events up to a maximum of one hundred  eighty
(180) days),  then Tenant may terminate this Lease by delivering  written notice
to  Landlord  of its  election to  terminate  within  thirty (30) days after the
Damage  Notice  has been  delivered  to  Tenant.  If  Tenant  does not so timely
terminate this Lease, then (subject to Section 14.(c)) Landlord shall repair the
Building as provided  below,  and Rent for the portion of the Building  rendered
untenantable  by the damage shall be abated on a reasonable  basis from the date
of damage until the completion of the repair,  unless a Tenant Party caused such
damage, in which case, Tenant shall continue to pay Rent without abatement.

                  (c)......Landlord's  Rights.  If a Casualty damages a material
portion of the Building during the last three (3) years of the Term (as the Term
may be extended  pursuant to the  provisions of Exhibit G), and Landlord makes a
good faith  determination that restoring the Building would be uneconomical,  or
if Landlord is required to pay at least  $50,000.00  of any  insurance  proceeds
arising  out of the  Casualty  to a  Landlord's  Mortgagee,  then  Landlord  may
terminate  this Lease by giving  written  notice of its  election  to  terminate
within  thirty (30) days after the Damage  Notice has been  delivered to Tenant,
and  Basic  Rent  and  Additional  Rent  shall be  abated  as of the date of the
Casualty.



<PAGE>


                  (d)......Repair   Obligation.   If  neither  party  elects  to
terminate  this Lease  following  a  Casualty,  then  Landlord  shall,  within a
reasonable  time after such  Casualty,  begin to repair the  Building  and shall
proceed with reasonable  diligence to restore the Building to substantially  the
same condition as it existed immediately before such Casualty; however, Landlord
shall not be  required  to repair or replace  any of the  furniture,  equipment,
fixtures,  and  other  improvements  which may have  been  placed  by, or at the
request of,  Tenant or other  occupants  in the  Building or the  Premises,  and
Landlord's  obligation  to repair or restore the  Building or Premises  shall be
limited to the extent of the insurance  proceeds  actually  received by Landlord
for the Casualty in question.

         15.  Personal  Property  Taxes.  Tenant  shall be liable  for all taxes
levied or assessed against personal property,  furniture,  or fixtures placed by
Tenant in the  Premises.  If any taxes for which  Tenant is liable are levied or
assessed against Landlord or Landlord's  property and Landlord elects to pay the
same, or if the assessed value of Landlord's  property is increased by inclusion
of such personal property,  furniture or fixtures and Landlord elects to pay the
taxes based on such  increase,  then Tenant shall pay to Landlord,  upon demand,
the part of such taxes for which Tenant is primarily liable hereunder;  however,
Landlord  shall not pay such  amount if Tenant  notifies  Landlord  that it will
contest the validity or amount of such taxes before Landlord makes such payment,
and thereafter  diligently proceeds with such contest in accordance with law and
if the  non-payment  thereof  does not pose a threat of loss or  seizure  of the
Building or interest  of Landlord  therein or impose any fee or penalty  against
Landlord.

         16. Events of Default.  Each of the following  occurrences  shall be an
"Event of Default":

                  (a)......Tenant's  failure  to pay Rent  within  five (5) days
after  Landlord  has  delivered  written  notice to Tenant that the same is due;
however,  an Event of Default shall occur  hereunder  without any  obligation of
Landlord to give any notice if Landlord  has given Tenant  written  notice under
this Section  16.(a) on two (2) occasions  during the twelve (12) month interval
preceding such failure by Tenant;

                  (b)......For  more than thirty (30)  consecutive  days or more
than  thirty  (30) days in a ninety  (90) day  period,  Tenant (1)  abandons  or
vacates the Building or more than  twenty-five  percent  (25%)  thereof,  or (2)
fails to continuously operate its business in the Building for the Permitted Use
set forth herein;

                  (c)......Tenant  fails to  provide  any  estoppel  certificate
within the time period  required  under  Section  24.(e) and such failure  shall
continue for five (5) days after written notice thereof from Landlord to Tenant;



<PAGE>


                  (d)......Tenant's  failure to perform, comply with, or observe
any other agreement or obligation of Tenant under this Lease and the continuance
of such  failure for a period of more than thirty (30) days after  Landlord  has
delivered to Tenant written notice  thereof;  provided that if the default is of
such a nature that it may not be reasonably  cured within thirty (30) days, then
no Event of Default shall occur hereunder if Tenant commences curing within such
thirty (30) day period and thereafter  diligently and continuously  pursues such
cure to completion  within a period of not more than  forty-five (45) days after
the delivery of such notice; and

                  (e)......The  filing of a petition  by or against  Tenant (the
term  "Tenant"  shall  include,  for the  purpose of this  Section  16.(e),  any
guarantor of Tenant's  obligations  hereunder);  (1) in any  bankruptcy or other
insolvency proceeding;  (2) seeking any relief under any state or federal debtor
relief law;  (3) for the  appointment  of a  liquidator  or receiver  for all or
substantially  all of Tenant's  property or for Tenant's interest in this Lease;
or (4) for the  reorganization  or modification of Tenant's  capital  structure;
however,  if such a petition is filed against Tenant, then such filing shall not
be an Event of Default unless Tenant fails to have the proceedings  initiated by
such petition dismissed within sixty (60) days after the filing thereof.

         17.  Remedies.  Upon an Event of Default,  Landlord may, in addition to
all other  rights and  remedies  afforded  Landlord  hereunder,  take any of the
following actions:

                  (a)......Terminate  this Lease by giving Tenant written notice
thereof,  in which event  Tenant  shall pay to Landlord  the sum of (1) all Rent
accrued  hereunder  through the date of termination,  (2) all amounts dues under
Section 18.(a),  and (3) an amount equal to (A) the total Rent that Tenant would
have been required to pay for the remainder of the Term plus Landlord's estimate
of aggregate  expenses of reletting to the Premises,  minus (B) the then present
fair rental rate value of the Premises for such period;



<PAGE>


                  (b)......Terminate  Tenant's  right to  possess  the  Premises
without  terminating  this Lease by giving written notice thereof to Tenant,  in
which event Tenant shall pay to Landlord (1) all Rent and other amounts  accrued
hereunder to the date of  termination  of  possession,  (2) all amounts due from
time to time under Section 18.(a),  and (3) all Rent and other net sums required
hereunder to be paid by Tenant during the  remainder of the Term,  diminished by
any net sums  thereafter  received by Landlord  through  reletting  the Premises
during such period,  after deducting all costs incurred by Landlord in reletting
the Premises.  Landlord  shall use  reasonable  efforts to relet the Premises on
such terms as Landlord in its sole  discretion  may determine  (including a term
different from the Term, rental concessions, and alterations to, and improvement
of,  the  Premises);  however,  Landlord  shall  not be  obligated  to relet the
Premises before leasing space in any building owned by Landlord or any Affiliate
thereof  within  a  one  (1)  mile  radius  of  the  Building  (the  "Affiliated
Buildings").  Landlord shall not be liable for, nor shall  Tenant's  obligations
hereunder be diminished  because of, Landlord's failure to relet the Premises or
to collect  rent due for such  reletting.  Tenant  shall not be  entitled to the
excess of any  consideration  obtained by reletting over the Rent due hereunder.
Reentry  by  Landlord  in the  Premises  shall not affect  Tenant's  obligations
hereunder for the unexpired Term; rather, Landlord may, from time to time, bring
an action against Tenant to collect amounts due by Tenant, without the necessity
of Landlord's waiting until the expiration of the Term. Unless Landlord delivers
written notice to Tenant expressly stating that it has elected to terminate this
Lease,  all actions taken by Landlord to  dispossess or exclude  Tenant from the
Premises  shall be deemed to be taken  under this  Section  17.(b).  If Landlord
elects  to  proceed  under  this  Section  17.(b),  it may at any time  elect to
terminate this Lease under Section 17.(a); and

                  (c)......Additionally,  without  notice and provided  Landlord
has  exercised  its rights and remedies set forth in either clause (a) or clause
(b) above, Landlord may alter locks or other security devices at the Premises to
deprive Tenant of access thereto,  and Landlord shall not be required to provide
a new key or right of access to Tenant.

         Any and all remedies set forth in this Lease:  (i) shall be in addition
to any and all other remedies Landlord may have at law or in equity;  (ii) shall
be cumulative; and (iii) may be pursued successively or concurrently as Landlord
may  elect.  The  exercise  of any  remedy  by  Landlord  shall not be deemed an
election of remedies or preclude  Landlord from exercising any other remedies in
the future.  Notwithstanding  the  foregoing,  Landlord  shall only  recover its
damages allowed hereunder once.

         18.      Payment by Tenant; Non-Waiver.

                  (a)......Payment by Tenant. Upon any Event of Default,  Tenant
shall pay to Landlord all costs incurred by Landlord  (including court costs and
reasonable  attorneys'  fees and  expenses) in (1)  obtaining  possession of the
Premises,  (2) removing and storing Tenant's or any other  occupant's  property,
(3)  repairing,  restoring,  altering,  remodeling,  or  otherwise  putting  the
Premises into condition reasonably  acceptable to a new tenant, (4) if Tenant is
dispossessed of the Premises and this Lease is not terminated,  reletting all or
any part of the Premises (including brokerage commissions, cost of tenant finish
work, and other costs  incidental to such  reletting),  (5) performing  Tenant's
obligations  which  Tenant  failed to perform,  and (6)  enforcing,  or advising
Landlord of, its rights,  remedies,  and  recourses  arising out of the Event of
Default.  To the full extent  permitted  by law,  Landlord  and Tenant agree the
federal and state courts of Massachusetts shall have exclusive jurisdiction over
any matter  relating to or arising from this Lease and the  parties'  rights and
obligations under this Lease.

                  (b)......No Waiver. Landlord's acceptance of Rent following an
Event of  Default  shall not waive  Landlord's  rights  regarding  such Event of
Default.  No waiver by Landlord of any  violation  or breach of any of the terms
contained herein shall waive Landlord's rights regarding any future violation of
such term.  Landlord's acceptance of any partial payment of Rent shall not waive
Landlord's  rights with regard to the remaining portion of the Rent that is due,
regardless of any endorsement or other statement on any instrument  delivered in
payment of Rent or any writing delivered in connection  therewith;  accordingly,
Landlord's  acceptance  of a partial  payment  of Rent shall not  constitute  an
accord and satisfaction of the full amount of the Rent that is due.

         19. Landlord's Lien. Intentionally omitted,  provided that the deletion
of this Section shall not be construed to be a waiver of Landlord's  lien rights
provided by law.



<PAGE>


         20.  Surrender  of  Premises.  No act by  Landlord  shall be  deemed an
acceptance  of a  surrender  of the  Premises,  and no  agreement  to  accept  a
surrender of the  Premises  shall be valid unless it is in writing and signed by
Landlord.  At the expiration or termination of this Lease,  Tenant shall deliver
to Landlord the Premises with all  improvements  located  therein in good repair
and condition,  free of Hazardous  Materials  placed on the Premises  during the
Term,  broom-clean,  reasonable  wear and tear (and  condemnation  and  Casualty
damage not  caused by  Tenant,  as to which  Sections  13 and 14 shall  control)
excepted, and shall deliver to Landlord all keys to the Premises.  Provided that
Tenant has performed  all of its  obligations  hereunder,  Tenant may remove all
unattached  trade  fixtures,  furniture,  and  personal  property  placed in the
Premises by Tenant, and shall remove such alterations,  additions, improvements,
trade fixtures, personal property,  equipment, wiring, and furniture as Landlord
may request.  Tenant shall repair all damage caused by such  removal.  All items
not so  removed  shall be  deemed to have been  abandoned  by Tenant  and may be
appropriated,  sold,  stored,  destroyed,  or otherwise  disposed of by Landlord
without  notice to Tenant and without any  obligation to account for such items.
The provisions of this Section 20 shall survive the end of the Term.

         21.  Holding Over. If Tenant fails to vacate the Premises at the end of
the Term,  then  Tenant  shall be a tenant at will and, in addition to all other
damages  incurred  by  Landlord  from and  after  ninety  (90)  days  after  the
expiration of this Lease and remedies to which Landlord may be entitled for such
holding  over,  Tenant  shall pay, in addition to the other Rent,  a daily Basic
Rent equal to 200% of the daily Basic Rent payable  during the last month of the
Term.  The  provisions  of this  Section  21  shall  not be  deemed  to limit or
constitute a waiver of any other rights or remedies of Landlord  provided herein
or at law. If Tenant fails to surrender  the Premises  upon the  termination  or
expiration  of this  Lease,  in addition  to any other  liabilities  to Landlord
accruing therefrom,  Tenant shall protect,  defend,  indemnify and hold Landlord
harmless  from all  loss,  costs  (including  reasonable  attorneys'  fees)  and
liability  resulting  from  such  failure,   including,   without  limiting  the
generality of the foregoing,  any claims made by any  succeeding  tenant founded
upon such  failure to  surrender,  and any lost  profits to  Landlord  resulting
therefrom.

         22. Certain Rights Reserved by Landlord.  Provided that the exercise of
such rights does not  unreasonably  interfere  with  Tenant's  occupancy  of the
Premises, Landlord shall have the following rights:

                  (a)......To   decorate  and  to  make  inspections,   repairs,
alterations,   additions,  changes,  or  improvements,   whether  structural  or
otherwise,  in and about the Building,  or any part  thereof;  to enter upon the
Premises upon reasonable prior notice to Tenant (except in case of an emergency,
in which case no notice shall be required)  and,  during the  continuance of any
such work, to temporarily close doors, entryways, public space, and corridors in
the  Building;  to  interrupt  or  temporarily  suspend  Building  services  and
facilities;  and, to the extent required by governmental authorities,  to change
the arrangement and location of entrances or passageways,  doors,  and doorways,
corridors, elevators, stairs, restrooms, or other public parts of the Building;



<PAGE>


                  (b)......To  take such  reasonable  measures as Landlord deems
advisable  for the security of the Building and its  occupants;  evacuating  the
Building for cause, suspected cause, or for drill purposes;  temporarily denying
access to the Building; and closing the Building after normal business hours and
on Sundays and holidays,  subject,  however, to Tenant's right to enter when the
Building is closed after normal business hours under such reasonable regulations
as Landlord may prescribe from time to time; and

                  (c)......To enter the Premises at  reasonable  hours to show
the Premises to  prospective  purchasers,  lenders,  or,
during the last twelve (12) months of the Term, tenants.

         23.      [Intentionally Omitted].

         24.      Miscellaneous.

                  (a)......Landlord  Transfer. Landlord may transfer any portion
of the Building and any of its rights under this Lease. If Landlord  assigns its
rights  under this Lease,  then  Landlord  shall  thereby be  released  from any
further  obligations  hereunder,  provided that the assignee assumes  Landlord's
obligations hereunder in writing.

                  (b)......Landlord's  Liability.  The  liability of Landlord to
Tenant  for any  default  by  Landlord  under the terms of this  Lease  shall be
limited to Tenant's actual direct, but not  consequential,  damages therefor and
shall be  recoverable  only from the interest of Landlord in the  Building,  and
Landlord shall not be personally  liable for any deficiency.  This Section shall
not limit any remedies  which Tenant may have for  Landlord's  defaults which do
not involve the personal liability of Landlord.

                  (c)......Force  Majeure.  Other than for Tenant's  obligations
under this Lease that can be performed by the payment of money (e.g., payment of
Rent  and  maintenance  of  insurance),  whenever  a  period  of time is  herein
prescribed  for action to be taken by either party hereto,  such party shall not
be liable or responsible  for, and there shall be excluded from the  computation
of any such  period of time,  any delays  due to  strikes,  riots,  acts of God,
shortages  of  labor or  materials,  war,  governmental  laws,  regulations,  or
restrictions,  or any other causes of any kind  whatsoever  which are beyond the
control of such party.  The  provisions of this Section 24(c) shall not apply to
Landlord's  obligations  to construct the Landlord Work and Tenant  Improvements
pursuant to the provisions of this Lease.

                  (d)......Brokerage. Neither Landlord nor Tenant has dealt with
any broker or agent in  connection  with the  negotiation  or  execution of this
Lease, other than Grubb & Ellis Management  Services,  Inc. and Fallon,  Hines &
O'Connor, whose commission shall be paid by Landlord.  Tenant and Landlord shall
each indemnify the other against all costs, expenses, attorneys' fees, and other
liability for commissions or other  compensation  claimed by any broker or agent
claiming the same by, through, or under the indemnifying party.



<PAGE>


                  (e)......Estoppel  Certificates.  From  time to  time,  Tenant
shall furnish to any party designated by Landlord, within ten (10) business days
after  Landlord  has made a written  request  therefor (a copy of which  request
shall  be  simultaneously  sent  to  the  Law  Department  at the  Premises),  a
certificate   signed  by  Tenant   confirming   and   containing   such  factual
certifications  and  representations as to this Lease as Landlord may reasonably
request.

                  (f)......Notices.  All notices and other  communications given
pursuant  to this  Lease  shall be in  writing  and shall be (1) mailed by first
class,  United States Mail,  postage  prepaid,  certified,  with return  receipt
requested,  and addressed to the parties hereto at the address specified next to
their signature block, (2) hand delivered to the intended  address,  or (3) sent
by prepaid  telegram,  cable,  facsimile  transmission,  or telex  followed by a
confirmatory letter. All notices shall be effective upon delivery to the address
of the addressee. The parties hereto may change their addresses by giving notice
thereof to the other in conformity with this provision.

                  (g)......Separability.  If any  clause  or  provision  of this
Lease is illegal,  invalid,  or unenforceable under present or future laws, then
the  remainder  of this Lease shall not be affected  thereby and in lieu of such
clause or  provision,  there  shall be added as a part of this Lease a clause or
provision as similar in terms to such illegal,  invalid, or unenforceable clause
or provision as may be possible and be legal, valid, and enforceable.

                  (h)......Amendments; and Binding Effect. This Lease may not be
amended  except by  instrument  in writing  signed by Landlord  and  Tenant.  No
provision  of this  Lease  shall be deemed to have been  waived by  Landlord  or
Tenant  unless such waiver is in writing  signed by Landlord and Tenant,  and no
custom or practice which may evolve between the parties in the administration of
the terms  hereof  shall  waive or  diminish  the right of Landlord or Tenant to
insist  upon the  performance  by  Tenant in  strict  accordance  with the terms
hereof.  The terms and  conditions  contained  in this Lease  shall inure to the
benefit of and be binding  upon the parties  hereto,  and upon their  respective
successors  in interest and legal  representatives,  except as otherwise  herein
expressly  provided.  This Lease is for the sole benefit of Landlord and Tenant,
and,  other than  Landlord's  Mortgagee,  no third party shall be deemed a third
party beneficiary hereof.

                  (i)......Quiet Enjoyment. Provided Tenant has performed all of
its obligations hereunder, Tenant shall peaceably and quietly hold and enjoy the
Premises for the Term, without hindrance from Landlord or any party claiming by,
through,  or  under  Landlord,  but not  otherwise,  subject  to the  terms  and
conditions of this Lease.

                  (j)......No Merger.  There shall be no merger of the leasehold
estate hereby created with the fee estate in the Premises or any part thereof if
the same person  acquires or holds,  directly or  indirectly,  this Lease or any
interest  in this  Lease and the fee  estate in the  leasehold  Premises  or any
interest in such fee estate.



<PAGE>


                  (k)......No Offer.  The  submission  of this Lease to Tenant
shall not be construed  as an offer,  and neither  party
                           --------
shall have any rights under this Lease until both parties execute a copy of 
this Lease.

                  (l)......Entire  Agreement.  This Lease constitutes the entire
agreement  between  Landlord and Tenant  regarding the subject matter hereof and
supersedes all oral statements and prior writings relating  thereto.  Except for
those set forth in this Lease,  no  representations,  warranties,  or agreements
have been made by Landlord or Tenant to the other with  respect to this Lease or
the obligations of Landlord or Tenant in connection  therewith.  The normal rule
of  construction  that any  ambiguities  be resolved  against the drafting party
shall  not  apply  to the  interpretation  of  this  Lease  or any  exhibits  or
amendments hereto.

                  (m)......Waiver of Jury Trial.  To the  maximum  extent  
permitted  by law,  Landlord  and Tenant each waive right to
                           --------------------
trial by jury in any litigation arising out of or with respect to this Lease.

                  (n)......Governing  Law. This Lease shall be governed by and
  construed in  accordance  with the laws of the State in
                           --------------
which the Premises are located.

                  (o)......Joint and Several  Liability.  If Tenant is comprised
of more than one party,  each such party shall be jointly and  severally  liable
for Tenant's obligations under this Lease. If Landlord is comprised of more than
one party,  each such party shall be jointly and severally liable for Landlord's
obligations under this Lease.

                  (p)......Financial  Reports.  Within  fifteen  (15) days after
Landlord's  request,  Tenant will furnish Tenant's most recent audited financial
statements  (including  any notes to them) to  Landlord,  or, if no such audited
statements  have been prepared,  such other  financial  statements (and notes to
them) as may have been prepared by an independent  certified  public  accountant
or, failing those,  Tenant's  internally prepared financial  statements.  Tenant
will discuss its  financial  statements  with  Landlord  and will give  Landlord
access to Tenant's  books and records in order to enable  Landlord to verify the
financial  statements.  Landlord  will  not  disclose  any  aspect  of  Tenant's
financial  statements that Tenant designates to Landlord as confidential  except
(1) to Landlord's  Mortgagee or prospective  purchasers of the Building,  (2) in
litigation between Landlord and Tenant, and/or (3) if required by court order.

                  (q)......Landlord's Fees. Whenever Tenant requests Landlord to
take any action or give any  consent  required  or  permitted  under this Lease,
Tenant will reimburse Landlord for Landlord's  reasonable,  actual out-of-pocket
costs incurred in reviewing the proposed  action or consent,  including  without
limitation reasonable attorneys',  engineers' or architects' fees, within thirty
(30) days after  Landlord's  delivery  to Tenant of a  statement  of such costs.
Tenant will be obligated to make such  reimbursement  without  regard to whether
Landlord consents to any such proposed action.



<PAGE>


                  (r)......Telecommunications.  Subject  to  the  provisions  of
Section 7 above,  Tenant, at its sole cost and expense and with Landlord's prior
written consent (which consent shall not be  unreasonably  withheld or delayed):
(i) may install  underground fiber optic lines within the Premises;  and (ii) to
the extent Landlord  continues to own the 4 Omni Way Offer Space (as hereinafter
defined)  and Tenant  leases the 4 Omni Way Offer  Space,  may use any  existing
telecommunications   systems  (including,   without  limitation,   any  existing
underground  tunnels and/or  conduits)  located on the 4 Omni Way Offer Space or
any future  telecommunications  systems  located on such Space and  approved  by
Landlord.  Notwithstanding any provisions of this Section 24(r) to the contrary,
Landlord  shall not be deemed to have  unreasonably  withheld its consent to any
installation that would affect the Building's  structure or its HVAC,  plumbing,
electrical,  or  mechanical  systems or any other  improvements  or any of their
respective  HVAC,  plumbing,  electrical or mechanical  systems,  if any. Tenant
shall  promptly  repair and restore any damage  caused by any such  installation
and, upon Landlord's  request,  at the earlier termination or expiration of this
Lease,  Tenant shall restore the Premises and any other affected property to the
condition that existed on the date of this Lease. Any and all such installations
of fiber optic lines shall comply with all applicable Laws. Tenant  acknowledges
and  agrees  that  Tenant's  right  to  use  any  such  existing  and/or  future
telecommunications systems shall not be exclusive and that Landlord is in no way
making any representations or warranties with respect to such telecommunications
systems,  including,  without limitation, any representations or warranties with
respect to the  structural  integrity,  the adequacy  and/or utility of any such
telecommunications systems and/or their compliance with applicable Laws.

                  (s)......General  Definitions.  The following terms shall have
the following meanings:  "Laws" means all federal,  state, and local laws, rules
and regulations,  all court orders, all governmental directives and governmental
orders, and all restrictive  covenants  affecting the Property,  and "Law" means
any of the foregoing;  "Affiliate" means any person or entity which, directly or
indirectly,  controls,  is  controlled  by, or is under common  control with the
party in question;  "Tenant Party" shall include Tenant,  any assignees claiming
by, through,  or under Tenant,  any subtenants  claiming by,  through,  or under
Tenant,  and any  agents,  contractors,  employees,  invitees  of the  foregoing
parties; and "including" means including, without limitation.

                  (t)......Confidentiality.  Tenant  acknowledges that the terms
and conditions of this Lease are to remain  confidential for Landlord's benefit,
and may not be disclosed by Tenant to anyone,  by any manner or means,  directly
or indirectly,  without Landlord's prior written consent, other than to Tenant's
lender's, accountants,  attorneys or other advisors on a need to know basis only
provided  such  advisors  agree to keep the terms and  conditions  of this Lease
confidential.  The consent by Landlord to any disclosures shall not be deemed to
be a waiver  on the part of  Landlord  of any  prohibition  against  any  future
disclosure.



<PAGE>


                  (u)......Hazardous  Materials.  The term "Hazardous Materials"
means any substance,  material, or waste which is now or hereafter classified or
considered  to be  hazardous,  toxic,  or  dangerous  under any Law  relating to
pollution or the protection or regulation of human health,  natural resources or
the environment,  or poses or threatens to pose a hazard to the health or safety
of persons on the Premises or in the Building.  Tenant shall not use,  generate,
store,  or dispose  of, or permit the use,  generation,  storage or  disposal of
Hazardous  Materials on or about the Premises or the Building except in a manner
and quantity necessary for the ordinary  performance of Tenant's  business,  and
then in compliance with all Laws. If Tenant breaches its obligations  under this
Section  24.(u),  Landlord may  immediately  take any and all action  reasonably
appropriate to remedy the same, including taking all appropriate action to clean
up or remediate any  contamination  resulting  from  Tenant's  use,  generation,
storage or disposal of Hazardous Materials.  Tenant shall defend, indemnify, and
hold harmless Landlord and its  representatives  and agents from and against any
and all  claims,  demands,  liabilities,  causes of  action,  suits,  judgments,
damages  and  expenses  (including  attorneys'  fees  and  cost of  clean up and
remediation) arising from Tenant's failure to comply with the provisions of this
Section 24.(u). This indemnity provision shall survive termination or expiration
of the Lease.  Except as set forth in the Environmental  Reports (as hereinafter
defined),  to the actual knowledge of Landlord,  Landlord  represents that there
are no Hazardous Materials on the Premises as of the date of this Lease. For the
purposes  hereof,  "Environmental  Reports"  shall  mean  that  certain  Phase I
Environmental  Site Assessment and Subsurface  Investigation  Report prepared in
October, 1997 by ENSR in connection with, among other properties, the Premises.

                  (v)......List of Exhibits.  All exhibits and attachments 
attached hereto are incorporated herein by this reference.
                           ----------------

                 Exhibit   A   -.......Site   Plan  of   Premises  
                 Exhibit   B   -.......Legal    Description    of    Building
                 Exhibit   C   -.......Premises  Rules and  Regulations
                 Exhibit   D   - Landlord Work and Tenant  Improvements
                 Exhibit   E   - Parking 
                 Exhibit   F   - Sample Letter of Credit 
                 Exhibit   G   - Renewal Option 
                 Exhibit   H   - First Amendment to Lease 
                 Exhibit   I   - Building Holidays
                 Exhibit   J   - Form of Subordination, Non-disturbance and
                    Attornment Agreement
                 Exhibit   K   - Right of First Offer Re: 4 Omni Way

                  (w)......Time of Essence.  Time is of the essence of this
                                      Lease and each and all of its provisions.
                           --------------- 

                  (x)......Notice  of Lease.  Tenant  agrees not to record  this
Lease and,  subject to the provisions of Section 24(t) above,  to keep the terms
of this Lease confidential,  but each party hereto agrees, at the request of the
others to execute a so-called  Notice of Lease in recordable form complying with
applicable law and reasonably  satisfactory to Landlord's attorneys. In no event
shall  such  document  set forth  the Rent or other  charges  payable  by Tenant
hereunder.



<PAGE>


                  (y)......First  Amendment to Lease. Tenant agrees that, within
ten (10)  business days of  Landlord's  request,  it will execute and deliver to
Landlord  the First  Amendment  to Lease  attached  hereto as  Exhibit H setting
forth, among other things, the actual  Commencement Date and the date upon which
the Term expires.

                  (z)......Corporate  Approval.  Concurrently with its execution
of the Lease,  each of Tenant and  Landlord  shall  provide the other party with
duly  authorized  and  executed  corporate  resolutions  (in form and  substance
reasonably  satisfactory to the other party's counsel)  authorizing the entering
into  and  consummation  of the  transactions  contemplated  by this  Lease  and
designating  the corporate or other officer or officers to execute this Lease on
behalf of the applicable party.

                  (aa).....Building Signage. Subject to Landlord's prior written
consent (which shall not be unreasonably  withheld or delayed),  compliance with
all Laws and at the Tenant's  sole cost and expense,  Tenant may erect  exterior
building signage.



<PAGE>


                  (bb).....Rooftop  Equipment.  Tenant may install,  at Tenant's
risk and expense and to be used  solely by Tenant,  a dish style  antennae of no
more than five (5) feet in diameter (the "Rooftop Equipment") on the roof of the
Building  at a location  approved by  Landlord.  Before  installing  the Rooftop
Equipment,   Tenant  shall  submit  to  Landlord  for  its  approval  plans  and
specifications which (A) specify in detail the design,  location and size of the
Rooftop   Equipment   (and,  with  respect  to  the  Rooftop   Equipment,   such
specifications  shall also contain the frequency of such  equipment) and (B) are
sufficiently  detailed to allow for the installation of the Rooftop Equipment in
a good and  workmanlike  manner  and in  accordance  with all Laws.  None of the
Rooftop  Equipment shall protrude more than five (5) feet above the elevation of
the roof on which it is installed  and all such  equipment  must be painted in a
color  reasonably  acceptable  to Landlord to minimize  visibility.  If Landlord
approves of such plans (which  approval  shall not be  unreasonably  withheld or
delayed unless the  installation of any Rooftop  Equipment  penetrates the roof,
affects the Building's structure or any of its HVAC, mechanical,  electrical and
plumbing  equipment,  or violates or in any way  compromises any roof warranty),
Tenant shall install (in a good and  workmanlike  manner),  maintain and use the
Rooftop  Equipment in accordance with all Laws and shall obtain all consents and
permits required for the installation and operation thereof;  copies of all such
permits and  evidence of such  consents  must be  submitted  to Landlord  before
Tenant begins to install the Rooftop Equipment. Tenant shall thereafter maintain
all permits necessary for the maintenance and operation of the Rooftop Equipment
while it is on the Building. Landlord may require that Tenant screen the Rooftop
Equipment with a parapet or other screening device  acceptable to Landlord.  All
electrical  usage for the Rooftop  Equipment shall be separately  metered or, at
Landlord's  election,  shall  be  placed  on the  same  electrical  meter as the
Premises.  Tenant shall maintain the Rooftop  Equipment and screening  device in
good repair and  condition.  Landlord  may  relocate  the Rooftop  Equipment  to
another  location on the roof of the  Building at its sole cost and expense upon
prior written  notice to Tenant so long as the new location does not  materially
interfere with Tenant's  reception  received by the satellite or antennae.  Upon
reasonable  prior notice to  Landlord,  Tenant  shall,  at its risk and expense,
remove the Rooftop Equipment (including all wiring related thereto), within five
(5)  days  after  the  occurrence  of any  of  the  following  events:  (i)  the
termination of Tenant's right to possess the Premises;  (ii) the  termination of
the Lease;  (iii) the  expiration  of the Term;  or (iv) the  Premises  shall be
vacated  by Tenant  and any and all  assignees  and/or  sublessees  approved  by
Landlord  hereunder.  If Tenant  fails to do so,  Landlord may remove all or any
part of the Rooftop  Equipment and store or dispose of it in any manner Landlord
deems appropriate  without liability to Tenant;  Tenant shall reimburse Landlord
for all costs incurred by Landlord in connection  therewith within ten (10) days
after  Landlord's  request  therefor.  Tenant  shall  repair  any  damage to the
Building caused by or relating to the Rooftop Equipment, including that which is
caused by its  installation,  maintenance,  use, or removal and shall  indemnify
Landlord against all liabilities,  losses,  damages,  and costs arising from the
installation,  maintenance, use, or removal of the Rooftop Equipment (unless the
liabilities,  losses,  damages,  and costs in question were caused by Landlord's
sole or gross negligence or wilful misconduct). All work relating to the Rooftop
Equipment shall, at Tenant's  expense,  be coordinated  with Landlord's  roofing
contractor  so as not to affect any warranty for the  Building's  roof and shall
not penetrate the roof.

(cc).....Access.  Tenant shall have  twenty-four  (24) hour access to the 
Premises  seven (7) days a week (subject to                         
force majeure, emergency, etc.).

                  (dd).....Arbitration.   (1)  In  any   case  in  which  it  is
specifically  provided  by the  terms  of this  Lease  that a  matter  shall  be
determined  by  arbitration,  such  arbitration  shall be conducted  pursuant to
applicable  statutes of The  Commonwealth of Massachusetts at the time in effect
and, to the extent  permitted by said statutes,  in the manner specified in this
Section 24(dd) and, to the extent not  inconsistent  with said statutes and this
Section 24(dd), in accordance with the Commercial  Arbitration Rules at the time
in effect of the American Arbitration Association; provided that all arbitrators
selected   hereunder   shall  be  persons  of  recognized   competence  who  are
unaffiliated  with either party  (either by direct or indirect  relationship  or
significant  business  relationship)  and shall  have at least  ten (10)  years'
experience as a commercial real estate broker or appraiser in the Greater Boston
area.

         (2) The party  desiring such  arbitration  shall give written notice to
that effect to the other party and, in such notice,  shall specify the nature of
the  dispute  to be  arbitrated  and shall  appoint  one of the  arbitrators  in
accordance with the requirements of Section 24(dd)(1).  Within fifteen (15) days
thereafter,  the other  party  shall by  written  notice to the  original  party
appoint a second person as an arbitrator in accordance with the  requirements of
this Section 24(dd)(1). The arbitrators thus appointed, within fifteen (15) days
of the appointment of the second such  arbitrator,  shall appoint a third person
in accordance  with the  requirements of Section  24(dd)(1),  and such three (3)
arbitrators shall determine such matter as promptly as possible; provided that:

 (A)......if the second  arbitrator shall not have been appointed as aforesaid,
  the first arbitrator shall proceed to
  determine the matter; and



<PAGE>


                  (B)......if the two (2)  arbitrators  appointed by the parties
                  shall be unable to agree  within  fifteen  (15) days after the
                  appointment of the second arbitrator upon the appointment of a
                  third  arbitrator,  they  shall  give  written  notice of such
                  failure to agree to the  parties,  and, if the parties fail to
                  agree  upon the  selection  of such  third  arbitrator  within
                  fifteen  (15) days  after  the  arbitrators  appointed  by the
                  parties given notice as  aforesaid,  then within ten (10) days
                  thereafter  either of the parties upon  written  notice to the
                  other  party,   may  request  such  appointment  by  the  then
                  Governing  Board of the New  England  Chapter of the  American
                  Institute of Real Estate  Appraisers (or any organization that
                  may be successor thereto) or, in its absence, refusal, failure
                  or  inability to act,  may apply for such  appointment  to any
                  Court of The  Commonwealth  of  Massachusetts  having  general
                  equity  powers or to any other court having  jurisdiction  and
                  exercising functions similar to such court.

         (3)  The  arbitrator  or  arbitrators  shall  have  the  right  only to
interpret  and apply the terms of this Lease,  and may not change any such terms
or deprive any party to this Lease of any right or remedy expressly or impliedly
provided  in this Lease.  Landlord  and Tenant each shall be entitled to present
evidence and arguments to the arbitrators.

         (4) The determination of the majority of the arbitrators or of the sole
arbitrator,  as the case may be, shall be final and binding in  accordance  with
the provisions of M.G.L.  c. 241. The  arbitrators  shall give written notice of
their  determination  to Landlord and Tenant and shall  furnish to each a signed
copy of such determination.

         (5) The fees and expenses of all arbitrators  shall be borne equally by
Landlord and Tenant.

         (6) In the event of the failure, refusal or inability of any arbitrator
to act, a new  arbitrator  shall be  appointed in his stead,  which  appointment
shall be made in the same manner as hereinbefore provided for the appointment of
the arbitrator so failing, refusing or unable to act, or to continue to act.

         (7) During any period of  arbitration  under this Section 24(dd) of any
matter stated in this Lease to be specifically  subject to arbitration,  neither
Landlord  nor  Tenant  shall be  deemed to be in  default  with  respect  to the
performance of any covenant, duty or obligation relating to such matter, and any
grace period or permitted delay in such  performance  otherwise  provided for in
this Lease shall be automatically extended by such period of arbitration.

                  (ee).....Campus Setting. At Tenant's request and sole cost and
expense,  Landlord shall use  reasonable  efforts to assist Tenant in creating a
campus environment;  provided,  however,  (i) any alterations to the Premises by
Tenant  shall be subject to the  provisions  of this  Lease,  including  without
limitation,  Section 7, (ii)  Landlord  shall not be required to render any such
assistance on a matter which would adversely  affect the Premises in any manner,
(iii) Landlord shall only render such  assistance  with respect to the Premises,
and (iv)  nothing  in this  Lease  is  intended  to  permit  Tenant  to make any
alterations to any property other than the Premises.



<PAGE>


                  (ff).....Termination  Agreement  with Sun  Microsystems.  This
Lease is subject to and contingent upon the execution and delivery of a mutually
acceptable  termination  agreement by and between Landlord and Sun Microsystems,
Inc.  respecting that certain Lease dated June 29, 1992 by and between  Teachers
Realty  Corporation  (the successor of which is Landlord) and Tenant  respecting
the  Premises  ("Sun  Microsystems  Termination  Agreement").  If, for  whatever
reason,  Landlord  and  Sun  Microsystems,  Inc.  do  not  enter  into  the  Sun
Microsystems  Termination  Agreement,  then this Lease  shall not be  effective,
Tenant shall have no rights  pursuant to this Lease,  and Landlord shall have no
obligations to Tenant hereunder.

                  (gg).....Termination  of 6 Omni Way  Lease.  The  Lease  dated
October 28, 1993 by and between  Teachers Realty  Corporation  (the successor of
which is Landlord)  and Tenant (the "6 Omni Way Lease") for the  property  known
and  numbered  as 6  Omni  Way,  Chelmsford,  Massachusetts  (the  "6  Omni  Way
Premises") shall be  automatically  terminated and, subject to the provisions of
this Section 24(gg), of no further force and effect upon the date  ("Termination
Date") that each of the following has occurred:

                           (i) the Commencement Date (as herein defined) has 
                               occurred;
                           (ii) Tenant is using and  occupying  the Premises (as
                           herein   defined)  for  the  Permitted   Use;   (iii)
                           [intentionally  omitted];  (iv)  Tenant has paid rent
                           and all other  amounts  due and  payable by Tenant to
                           Landlord for the period
                                    up through  and  including  the  Termination
                                    Date under the 6 Omni Way Lease  (including,
                                    without limitation,  all Taxes and Operating
                                    Expenses   due  and  owing  up  through  and
                                    including the Termination  Date which may be
                                    adjusted   after   the   Termination   Date;
                                    provided  however,  adjustments to Taxes and
                                    Operating  Expenses  may be paid  after  the
                                    Termination  Date  provided  such  Taxes and
                                    Operating  Expenses  are paid in  accordance
                                    with  the  provisions  of  the  6  Omni  Way
                                    Lease),  which obligations shall survive the
                                    early  termination  of the 6 Omni Way Lease;
                                    and
                  .........(v)      within sixty (60) days after the 
Commencement Date (as herein defined) (the "Scheduled Termination Date"),  
Tenant  has  vacated  and  surrendered  the 6 Omni Way  Premises  in an as-is 
broom-clean condition  (except  that Tenant  shall  disconnect  and remove the
two (2) ground  based HVAC units located on the 6 Omni Way Premises  and bring 
the power  source back to its  original  location and shall  restore the ground
covered by such HVAC units to the  condition  which existed prior to the
installation  of such HVAC units) and in  accordance  with the  provisions of
the 6 Omni Way Lease, including, without limitation, Sections 7.2, 14.21 and 
14.27 thereof.



<PAGE>


If Tenant fails to surrender the 6 Omni Way Premises in  accordance  with clause
(v) above,  Landlord shall have all rights and remedies  afforded Landlord under
the 6 Omni Way Lease, at law and in equity as if the Scheduled  Termination Date
were  the  expiration  date  of the  term of the 6 Omni  Way  Lease.  After  the
Termination  Date,  Tenant shall  perform all  obligations  under the 6 Omni Way
Lease which  expressly  survive the  expiration  or  termination  of such Lease,
including,  without limitation,  the provisions of Sections 10.1, 10.5 and 14.25
thereof.  Except as set forth herein and provided that Tenant  surrenders  the 6
Omni Way  Premises  in  accordance  with this  Section  24(gg),  all  rights and
obligations  of the  parties  under the 6 Omni Way Lease  shall  cease as of the
Termination Date.

         25.      Other Provisions.

LANDLORD AND TENANT  EXPRESSLY  DISCLAIM ANY IMPLIED  WARRANTY THAT THE PREMISES
ARE SUITABLE FOR TENANT'S INTENDED  COMMERCIAL  PURPOSE AND, EXCEPT AS OTHERWISE
EXPRESSLY  PROVIDED  HEREIN,  TENANT'S  OBLIGATION TO PAY RENT  HEREUNDER IS NOT
DEPENDENT  UPON THE CONDITION OF THE PREMISES OR THE  PERFORMANCE BY LANDLORD OF
ITS OBLIGATIONS  HEREUNDER,  AND, EXCEPT AS OTHERWISE EXPRESSLY PROVIDED HEREIN,
TENANT SHALL CONTINUE TO PAY THE RENT, WITHOUT  ABATEMENT,  SETOFF OR DEDUCTION,
NOTWITHSTANDING  ANY BREACH BY LANDLORD OF ITS DUTIES OR OBLIGATIONS  HEREUNDER,
WHETHER EXPRESS OR IMPLIED.

                                    [Remainder of Page Intentionally Left Blank]


<PAGE>


         IN WITNESS WHEREOF,  and in consideration of the mutual entry into this
Lease and for other good and valuable consideration, and intending to be legally
bound,  each party hereto has caused this Lease Agreement to be duly executed as
a  Massachusetts  instrument  under  seal  as of the day and  year  first  above
written.


                                     TENANT:

                KRONOS INCORPORATED, a Massachusetts corporation


                                          By: /x/ Paul Lacy
                                          Name: Paul Lacy
                                          Title: Vice President Finance & Admin

                                     Address: Prior to the Commencement Date:

                                                       400 Fifth Avenue
                                                       Waltham, MA 02151
                                                       Telecopy: (781) 622-3950

                                     As of the Commencement Date:
                                                       400 Fifth Avenue
                                                       Waltham, MA 02151
                                                       Telecopy: (781) 622-3950


<PAGE>


                                    LANDLORD:

                                     W9/TIB REAL ESTATE LIMITED
                                     PARTNERSHIP, a Delaware limited partnership

                                     By:  W9/TIB Gen-Par, Inc., a Delaware
                                          corporation, its general partner



                                     By:      /s/ Stephen M. Abelman
                                     Name:  Stephen M. Abelman
                                     Title:  Assistant Vice President

                                     Address: c/o Archon Group, L.P.
                                              1275 K Street NW, Suite 900
                                              Washington, DC 20005
                                              Telecopy:         (202) 216-5801


                                                                          <PAGE>



                                       A-1

                                    EXHIBIT A

                              SITE PLAN OF PREMISES

                            [Map of Area Plot Plans]




<PAGE>



                                       B-1

                                    EXHIBIT B

                          LEGAL DESCRIPTION OF PREMISES

         Lot 2A as  shown  on  that  certain  plan  entitled  "Plan  of  Land of
Billerica Road Site, Chelmsford,  MA", which plan is recorded with the Middlesex
North District Registry of Deeds in Plan Book 143 as Plan 143.


<PAGE>



                                       C-1

                                    EXHIBIT C

                         PREMISES RULES AND REGULATIONS

         The following  rules and regulations  shall apply to the Premises,  the
Building,  the  parking  garage  associated  therewith,  and  the  appurtenances
thereto:

         1. Sidewalks, doorways, vestibules, halls, stairways, and other similar
areas shall not be  obstructed  by Tenant or used by Tenant for  purposes  other
than  ingress  and  egress to and from the  Building  and for going  from one to
another part of the Building.

         2.  Plumbing,  fixtures  and  appliances  shall  be used  only  for the
purposes for which designed, and no sweepings, rubbish, rags or other unsuitable
material  shall be thrown or  deposited  therein.  Damage  resulting to any such
fixtures  or  appliances  from  misuse  by Tenant or its  agents,  employees  or
invitees, shall be paid by Tenant.

         3. No signs,  advertisements  or notices shall be painted or affixed on
or to any  windows  or doors or other  part of the  Building  without  the prior
written  consent  of  Landlord.  No nails,  hooks or  screws  shall be driven or
inserted in any part of the Building except by Building  maintenance  personnel.
No curtains or other window treatments shall be placed between the glass and the
Building standard window treatments.

         4.  Landlord  may  prescribe  weight   limitations  and  determine  the
locations for safes and other heavy equipment or items, which shall in all cases
be placed in the Building so as to distribute  weight in a manner  acceptable to
Landlord  which may include the use of such  supporting  devices as Landlord may
require.  All damages to the Building  caused by the  installation or removal of
any  property of Tenant,  or done by Tenant's  property  while in the  Building,
shall be repaired at the expense of such tenant.

         5.  Tenant  shall  not  make  or  permit  any  vibration  or  improper,
objectionable or unpleasant noises or odors in the Building.

         6.  Tenant  shall  not use or keep in the  Building  any  flammable  or
explosive  fluid or substance,  except that Tenant may keep  flammable  cleaning
supplies  secured in a fireproof  cabinet or locker and  otherwise in accordance
with all applicable Laws.

         7. Tenant  shall not conduct any  activity on or about the  Premises or
Building which will draw pickets, demonstrators, or the like.


<PAGE>



                                       D-2

                                    EXHIBIT D

                      LANDLORD WORK AND TENANT IMPROVEMENTS

         1. Except as set forth in this Exhibit,  Tenant accepts the Premises in
their "AS-IS" condition on the date that this Lease is entered into.

         2. Landlord shall have no obligation to perform any work therein except
for the following  (collectively,  the "Landlord Work"): (i) Landlord will clean
the carpets in the Building; (ii) Landlord will repair any holes in the interior
walls of the  Building;  and  (iii)  the HVAC and  mechanical  systems  shall be
delivered in good working order.

         3. Tenant  shall  provide to Landlord for its  approval  final  working
drawings,  prepared by an architect  that has been  approved by Landlord  (which
approval shall not unreasonably be withheld),  of all  improvements  that Tenant
proposes to install in the  Premises;  such working  drawings  shall include the
partition  layout,  ceiling plan,  electrical  outlets and  switches,  telephone
outlets,  drawings for any  modifications to the mechanical and plumbing systems
of the Building,  and detailed plans and  specifications for the construction of
the improvements called for under this Exhibit in accordance with all applicable
governmental  laws, codes,  rules, and regulations.  If any of Tenant's proposed
construction work will affect the Building's HVAC,  electrical,  mechanical,  or
plumbing systems,  then the working drawings pertaining thereto must be approved
by the  Building's  engineer  of record.  Landlord's  approval  of such  working
drawings shall not be unreasonably withheld,  provided that (a) they comply with
all laws,  rules,  and  regulations,  (b) such working drawings are sufficiently
detailed to allow  construction  of the  improvements  in a good and workmanlike
manner,  and (c) the  improvements  depicted  thereon  conform  to the rules and
regulations  promulgated  from time to time by the Landlord for the construction
of tenant  improvements (a copy of which has been delivered to Tenant).  As used
herein,  "Working  Drawings" shall mean the final working  drawings  approved by
Landlord,  as amended from time to time by any  approved  changes  thereto,  and
"Work" shall mean all  improvements  to be constructed in accordance with and as
indicated on the Working Drawings.  Landlord's  approval of the Working Drawings
and/or  review of any of the Work shall not be a  representation  or warranty of
Landlord that such drawings and/or any Work, as applicable, are adequate for any
use or comply with any law, but shall merely be the consent of Landlord thereto.
Landlord shall, at Tenant's  request,  sign the Working Drawings to evidence its
review and  approval  thereof.  All  changes in the Work must  receive the prior
written  approval  of  Landlord,  and in the event of any such  approved  change
Tenant shall,  upon completion of the Work,  furnish  Landlord with an accurate,
reproducible "as-built" plan of the improvements as constructed.



<PAGE>


         4. The Work shall be performed only by contractors  and  subcontractors
approved  in writing  by  Landlord,  which  approval  shall not be  unreasonably
withheld.  All contractors and  subcontractors  shall be required to procure and
maintain insurance against such risks, in such amounts,  and with such companies
as Landlord may reasonably  require.  Certificates of such insurance,  with paid
receipts  therefor,  must be received by Landlord  before the Work is commenced.
Promptly upon Landlord's approval of the Working Drawings, Tenant shall commence
the  construction  of the  Work  and  diligently  and  continuously  pursue  the
completion  of the same.  The Work shall be performed in a good and  workmanlike
manner free of defects,  shall conform strictly with the Working  Drawings.  All
contractors and subcontractors  shall contact Landlord and schedule time periods
during which they may use Building facilities in connection with the Work (e.g.,
elevators, excess electricity, etc.).

         5.  The  entire  cost  of  performing  the  Work  (including,   without
limitation, design of the Work and preparation of the Working Drawings, costs of
construction,   labor  and  materials,  electrical  usage  during  construction,
additional  janitorial  services,  general  tenant  signage,  related  taxes and
insurance  costs, all of which costs are herein  collectively  called the "Total
Construction  Costs") in excess of the  Construction  Allowance (as  hereinafter
defined) shall be paid by Tenant.

         6.  Landlord  shall  provide to Tenant a  construction  allowance  (the
"Construction  Allowance") equal to the lesser of (a) $10.00 per rentable square
foot in the Premises or (b) the Total  Construction  Costs,  as adjusted for any
approved changes to the Work.

         Subject to the terms and  conditions of this Lease,  Landlord shall pay
the  Construction  Allowance to Tenant for the purpose of financing a portion of
the Work. As conditions to Tenant's right to receive the Construction Allowance:
(i) Tenant shall not be in default  under the Lease;  (ii) the Lease shall be in
full  force and  effect;  (iii) the Work  shall  be,  in  Landlord's  reasonable
discretion,  substantially  complete; and (iv) Tenant shall furnish to Landlord:
(A) a Certificate of Occupancy respecting the Premises; and (B) such evidence as
Landlord  may  reasonably  require to evidence  that all persons  furnishing  or
supplying  labor and materials in connection  with the  construction of the Work
have been paid and that no lien exists of record with respect thereto.  Landlord
shall fund the  Construction  Allowance  within  twenty (20)  business days from
Tenant's written request for the same provided that Tenant has complied with the
requirements set forth in the preceding sentence. Upon paying the full amount of
the Construction  Allowance to Tenant in accordance with the provisions  hereof,
Landlord shall have no further obligation to extend any credit to Tenant.

         7. In  consideration  for  Landlord's  management  and  supervision  of
services  performed in connection  with the Work,  Tenant shall pay to Landlord,
within ten (10) business days after demand  therefor,  the actual costs incurred
by  Landlord  to  review  the  Working   Drawings   and/or  any  drafts   and/or
modifications thereto and to review the construction of the Work.


<PAGE>



                                       E-1

                                    EXHIBIT E

                                     PARKING

         Landlord  shall  provide,  and Tenant may use three  hundred  one (301)
undesignated  parking  spaces in the  parking  garage/area  associated  with the
Building (the "Parking  Area") during the initial Term at no additional  charge.
After the initial Term,  Tenant may use such parking  spaces and pay for the use
of such parking  spaces at such rates and subject to such terms,  conditions and
regulations  as are from time to time  charged or  applicable  to patrons of the
Parking Area or similar parking areas.  If, for any reason,  Tenant is unable to
use all or any portion of the parking spaces to which it is entitled  hereunder,
then Tenant's  obligations to pay for such spaces shall be abated for so long as
Tenant does not have the use thereof; this abatement shall be in full settlement
of all claims that Tenant  might  otherwise  have  against  Landlord  because of
Landlord's failure or inability to provide Tenant with such parking spaces.


<PAGE>



                                       F-4

                                    EXHIBIT F

                             SAMPLE LETTER OF CREDIT

Beneficiary/Landlord:                           Issuance Date:
W9/TIB Real Estate Limited Partnership                               , 1998
                   -----------------------------------
c/o Archon Group, L.P.
1275 K Street NW, Suite 900                          Irrevocable Standby Letter
Washington, DC  20005                                of Credit No. 
                          --------------------
Applicant/Accountee/Tenant:             Credit Amount:  USD $160,000.00
Kronos Incorporated                                   Up to an Aggregate Thereof
                                        Date and Place of Expiry:
                                                                   , 1998
                                              At Our Counters in Boston, MA

Ladies and Gentlemen:

         We hereby issue our irrevocable  standby letter of credit in your favor
for the  account  of the  applicant  for an  aggregate  amount not to exceed ONE
HUNDRED SIXTY THOUSAND US DOLLARS  available for payment by presentation of your
draft(s)  drawn  on  ourselves  at  sight,  and  accompanied  by  the  following
documents:

         1. Your statement/certificate,  on your letterhead,  signed by a person
purporting to be your authorized officer/representative, appropriately completed
in the following form:

         A. "The  undersigned,  an authorized  officer/representative  of W9/TIB
Real Estate Limited  Partnership (the "Landlord"),  hereby certifies with regard
to __________  standby letter of credit no. __________ that Kronos  Incorporated
(the   "Tenant")  is  in  default   relative  to  the  Lease   Agreement   dated
________________, 1998 (the "Lease") by and between Landlord and Tenant and such
default has continued uncured beyond all applicable notice and grace periods."

                  OR

         B. "We are in receipt of _______________ Notice of Non-Extension of its
letter of credit no.  _______________ and Kronos Incorporated (the "Tenant") has
failed to provide a replacement letter of credit reasonably  acceptable to us as
of the date of our drawing and the Tenant  remains  liable to us pursuant to the
Lease."

         2. The original of this letter of credit (for  endorsement of drawing),
which will be returned unless the credit is fully utilized.

         Partial drawings are permitted.



<PAGE>


         Draft(s)  must  indicate  the name of the issuing  bank,  the letter of
credit  number and must be  presented  at this  office  (the  address  specified
below).

   
         It is a  condition  of this  letter of  credit  that it shall be deemed
automatically  extended without  amendment for an additional  period of one year
from  the  present  or each  future  expiration  date  hereof,  but  not  beyond
_________________  [NOTE:  30 days after  expiration of Lease],  unless at least
forty-five  (45)  days  prior  to any  such  expiration  date we  notify  you by
certified  mail,  that we elect not to so extend  this  letter of credit for any
such  additional  period.  Upon  receipt  by you of such  notice,  you may  draw
hereunder  your  draft(s) at sight on ourselves for the then full amount of this
letter of credit accompanied by your statement as specified above.
    

         This letter of credit is transferable in its entirety, but not in part,
to any successor  landlord under the Lease and may be successively  transferred.
If it is your intention to transfer your interest  hereunder,  kindly return the
letter of credit to us for  appropriate  endorsement  and  furnish  us with your
instructions.  Please note your  signature on your request for transfer  must be
authenticated  by your  bank.  (Transfer  form is  attached.)  In the  event  of
transfer all required documents are to be signed by the transferee.

         This letter of credit  sets forth in full the terms of our  obligations
to you,  and our  undertaking  shall not in any way be amended or  amplified  by
reference to any documents,  instruments or any agreement  referred to herein or
to which this letter of credit related, and such reference, if any, shall not be
deemed to incorporate herein by reference any document, instrument or agreement.

         Except as otherwise  expressly stated herein,  this letter of credit is
subject  to  the  "Uniform   Customs  and  Practice  for  Documentary   Credits,
International Chamber of Commerce, Publication N. 500 (1993 Revision)".

         We engage with you that all draft(s) drawn under and in compliance with
the terms and  conditions  of this  letter of credit  shall be duly  honored  on
presentation to us at our office at _______________,  Boston, MA _______,  Attn:
_______________, ____ Floor on or before the expiring date as specified above or
any automatically extended date herein before set forth.

                                Very truly yours,


                                                              By: 
                                                                   Name:  
                                                                   Title:  
  


<PAGE>


                                                      TRANSFER

                           This form is to be used  where a Letter  of Credit is
                            transferred in its entirety and no  substitution  of
                            invoices is involved.

                                                        Date


                                     Re:  Credit            issued or advised by

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


Gentlemen:

For value received, the undersigned beneficiary hereby irrevocably transfers to:



                                            (Name of Second Beneficiary)


                                                      (Address)


                                               (Name of Advising Bank)


                                                      (Address)

all rights of the undersigned beneficiary to draw under the above Letter of 
Credit in its entirety.

1. By this transfer, all rights of the undersigned beneficiary in such Letter of
Credit are  transferred  to the Second  Beneficiary  and the Second  Beneficiary
shall  have the sole  rights  as  beneficiary  thereof,  including  sole  rights
relating to any amendment,  whether  increases or extensions or other amendments
and whether now existing or hereafter  made.  All  amendments  are to be advised
direct to the Second  Beneficiary  without necessity of any consent of or notice
to the undersigned beneficiary.


<PAGE>


         The advice of such  Letter of Credit is returned  herewith,  and we ask
you to endorse the transfer on the reverse thereof, and forward it direct to the
Second Beneficiary with your customary notice of transfer,  or advise the letter
of credit to the Second Beneficiary by telex/SWIFT.

SIGNATURE AUTHENTICATED             Very truly yours,


(Bank)
                                       By:      ______________________________
(Authorized Signature)                 Name:     
                                       Title:                  


<PAGE>



                                       G-2

                                    EXHIBIT G

                                 RENEWAL OPTION

         Provided no Event of Default  exists at the time Tenant  exercises  its
option to extend this Lease and at the time the  extension  Term  commences  and
Tenant is occupying at least  seventy-five  percent (75%) of the Premises at the
time of such election, Tenant may renew this Lease for one (1) additional period
of five (5) years,  by  delivering  written  notice of the exercise  thereof not
later than ten (10) months  before the  expiration of the Term. On or before the
commencement  date of the extended  Term in question,  Landlord and Tenant shall
execute an amendment to this Lease extending the Term on the same terms provided
in this Lease, except as follows:

                  (a) The Basic Rent  payable  for each month  during  each such
extended Term shall be the Fair Market Rental Value, at the commencement of such
extended Term, for space of equivalent quality, size, utility and location, with
the length of the  extended  Term and the credit  standing of Tenant to be taken
into account;

                  (b)  Tenant  shall  have no  further  renewal  options  unless
expressly granted by Landlord in writing; and

                  (c)  Landlord  shall  lease to Tenant  the  Premises  in their
then-current  condition,  and Landlord shall provide to Tenant  mutually  agreed
upon allowances (e.g., moving allowance,  construction allowance,  and the like)
or other tenant inducements.

         Tenant's rights under this Exhibit shall terminate if (1) this Lease or
Tenant's right to possession of the Premises is  terminated,  (2) Tenant assigns
any of its interest in this Lease or sublets more than twenty-five percent (25%)
of the  Premises or (3) Tenant  fails to timely  exercise  its option under this
Exhibit, time being of the essence with respect to Tenant's exercise thereof.

         For purposes of this Lease,  the term "Fair Market  Rental Value" shall
mean the fair market rental value of the Premises as of the  commencement of the
extension Term and/or expansion space (as applicable),  as agreed by the parties
hereto.  In the event that  Landlord  and Tenant are unable to agree on the Fair
Market  Rental Value of the Premises for purposes  hereof within sixty (60) days
following  Tenant's  notice of its election to extend this Lease or to lease the
expansion  space,  then the same shall be determined by binding  arbitration  in
accordance with Section 24(dd).

         The arbitrators, as chosen pursuant to Section 24(dd), shall make their
respective  determinations based upon the following  assumptions and directions,
and the arbitrators shall be so instructed and duty bound with respect thereto:

                  (i) the  space is  available  in the then  rental  market  for
                  single tenant buildings of comparable  office buildings in the
                  495 North markets;



<PAGE>


                  (ii) Landlord has had a reasonable time to locate a tenant for
                  such space who rents with the  knowledge  of the uses to which
                  the space can be utilized;

                  (iii)  neither Landlord nor the prospective tenant is under a 
                         compulsion to rent;

                  (iv) such space is to be rented as a whole to a single  tenant
                  for general  office use for a term of at least five (5) years,
                  taking into  consideration such market factors and other lease
                  provisions as may then customarily be in effect and applicable
                  to the rental of such space in that location;

                  (v)  current  face  rents  (i.e.,  face  rents  on new  leases
                  executed   within  the  prior   twelve  (12)  months  of  such
                  determination  or rents for  extension  terms of older  leases
                  where the rents  were  agreed  upon or  determined  within the
                  prior twelve (12) months thereof, in either case (1) as stated
                  on the face of such lease or as  determined by such lease with
                  respect to an extension option set forth therein, (2) adjusted
                  so that such face  rents  include  all real  estate  taxes and
                  operating  costs for such  building for the calendar year next
                  immediately  prior to the year in which such extension  option
                  is to  become  effective,  and (3)  without  regard  to rental
                  concessions  of any  kind,  such as free  rent  periods,  rent
                  abatements,  build-out  allowances  or the  like)  then  being
                  obtained by  Landlord  for space in the  Affiliated  Buildings
                  shall be a factor in determining fair market rental value;

                  (vi) all Operating Costs and Taxes payable by Tenant under the
                  terms of this Lease  shall be payable on the same basis as set
                  forth in this Lease; and

                  (vii)  the space shall be considered as if rented "as-is".


<PAGE>



                                       H-2

                                    EXHIBIT H

                            FIRST AMENDMENT TO LEASE

         THIS FIRST  AMENDMENT  made this day of , 199__,  by and between W9/TIB
REAL  ESTATE  LIMITED  PARTNERSHIP(hereinafter  referred to as  "Landlord")  and
KRONOS INCORPORATED (hereinafter referred to as "Tenant").

                                                     WITNESSETH:

         WHEREAS,  Landlord  and  Tenant  did  enter  into  that  certain  Lease
Agreement, dated ____________,  1998 (hereinafter the "Lease") for the demise of
certain  property  located  at 2 Omni  Way,  Chelmsford,  Massachusetts  and all
improvements  located thereon (the  "Premises"),  which Premises and any and all
improvements located thereon are more particularly described therein;

         WHEREAS, all terms defined in the Lease shall have the same meanings
          when referred to herein;

         WHEREAS,   Landlord  has   requested   that  Tenant   acknowledge   the
"Commencement  Date" of the Lease,  pursuant to and in accordance with Section 2
thereof,  and Landlord has further  requested  Tenant to acknowledge and confirm
(i) its obligations  attendant upon such  Commencement  Date, (ii) the date upon
which the Term of the Lease expires (the "Expiration Date"),  pursuant to and in
accordance  with Section 2 thereof,  and (iii) that the  Landlord  Work has been
completed in accordance with the provisions of the Lease; and

         WHEREAS, Tenant has agreed to acknowledge the Commencement Date and the
Expiration Date of the Lease.

         NOW,  THEREFORE,  in  consideration  of the  premises  and  the  mutual
promises and covenants  contained  herein and in the Lease,  Landlord and Tenant
hereby agree as follows:

                  1. The Commencement Date of the Lease shall be _______________
                  and the  Expiration  Date of the  Lease  shall  be , and  such
                  respective  dates of commencement  and expiration of the Lease
                  shall, if different from the dates  designated in Section 2 of
                  the Lease,  be  substituted  therefor.  It is  understood  and
                  agreed by  Landlord  and Tenant  that any and all of  Tenant's
                  covenants  and  obligations  as by the  Lease  provided  shall
                  become effective as of the Commencement Date.

                  2. The Landlord Work has been completed in accordance with the
                  provisions   of  the  Lease,   and  Tenant  has  received  the
                  Construction Allowance from Landlord.



<PAGE>


         EXCEPT as hereby  modified  and amended,  all other terms,  provisions,
covenants  and  conditions  of the Lease are  ratified and  confirmed  and shall
remain and in full force and effect.

         IN  WITNESS  WHEREOF,  Landlord  and  Tenant  have  caused  this  First
Amendment to be executed by their duly authorized representatives on the day and
year above written.

WITNESS:                            LANDLORD:

                                      W9/TIB REAL ESTATE LIMITED
                                      PARTNERSHIP, a Delaware
                                            limited Partnership

                                      By:9/TIB Gen-Par, Inc., a Delaware
                                       corporation, its managing general partner


                                                     By:               
                                
    
 Name:                                                     Name:       
      
                                                          Title:    
                                              


WITNESS:              TENANT:

                                          KRONOS INCORPORATED, a Massachusetts
                                               corporation


                                               By:   
Name:                                              Name:                  
                                                   Title:                      


<PAGE>



                                       I-1

                                    EXHIBIT I

                                BUILDING HOLIDAYS

New Year's Day,  President's  Day,  Memorial Day,  Independence  Day, Labor Day,
Thanksgiving  Day, the day after  Thanksgiving  Day, and  Christmas Day (and the
following day when any such day occurs on Sunday).


<PAGE>



                                       J-9

                                    EXHIBIT J

             SUBORDINATION, NON-DISTURBANCE AND ATTORNMENT AGREEMENT


     This AGREEMENT is made and entered into as of ___________________, 1999, by
and  among  LaSalle  National  Bank,  as  Trustee  for  GS  Mortgage  Securities
Corporation II Commercial Mortgage Pass-Through Certificates,  Series 1998-GSFL1
("Lender"),  W9/TIB  Real Estate  Limited  Partnership  ("Landlord")  and Kronos
Incorporated ("Tenant").

     1.   RECITALS.

          1.1  Mortgage.  Lender  is  the  holder  of a  Promissory  Note  dated
________________, 19____, in the original principal amount of $_________________
of Landlord,  which is secured, inter alia, by a Mortgage and Security Agreement
(the  "Mortgage")  and  Assignment  of Lease and Rents (the "Lease  Assignment")
covering premises more particularly described in the Mortgage (the "Premises").

          1.2 Lease.  Landlord and Tenant entered into a Lease dated January __,
1999 (the "Lease"), whereby Landlord demised to Tenant a portion of the Premises
(the "Demised Premises").

     2.  CONSIDERATION.  The terms of the Lease constitute a material inducement
to Lender's consent thereto and entering into and performing this Agreement.

     3.  SUBORDINATION  OF THE  LEASE.  This Lease  shall be and is hereby  made
subject and subordinate to the Mortgage.

     4. NON-DISTURBANCE. Lender shall not, in the exercise of any right, remedy,
or  privilege  granted by the  Mortgage or the Lease  Assignment,  or  otherwise
available to Lender at law or in equity,  disturb Tenant's  possession under the
Lease so long as:

     (a)  Tenant  is not in  default  under any  provision  of the Lease or this
Agreement  beyond any  applicable  notice and/or cure periods at the time Lender
exercises any such right, remedy or privilege; and

     (b) The Lease at that time is in force and effect according to its original
terms, or with such amendments or  modifications  as Lender shall have approved,
if  such  approval  is  required  by the  terms  of the  Mortgage  or the  Lease
Assignment; and

     (c) Tenant thereafter  continues to fully and punctually perform all of its
obligations  under the Lease without  default  thereunder  beyond any applicable
cure period; and

     (d)  Tenant  attorns  to or at the  direction  of Lender,  as  provided  in
Paragraph 5.


<PAGE>


Without limiting the foregoing, and so long as the foregoing conditions are met,
Lender agrees that (i) Tenant will not be named as a party to any foreclosure or
other  proceeding  instituted  by Lender to enforce the terms of the Mortgage or
the Lease Assignment; (ii) any sale or other transfer of the Demised Premises or
of the  Landlord's  interest  in  the  Lease,  pursuant  to  foreclosure  or any
voluntary conveyance or other proceeding in lieu of foreclosure, will be subject
and subordinate to Tenant's possession under the Lease; and (iii) the Lease will
continue  in force and effect  according  to its  original  terms,  or with such
amendments  as Lender shall have  approved,  if such approval is required by the
terms and conditions of the Mortgage or the Lease Assignment.

     5.  ATTORNMENT.  Tenant shall attorn to Lender,  to any receiver or similar
official for the Demised Premises appointed at the instance and request, or with
the consent,  of Lender and to any person who acquires the Demised Premises,  or
the Landlord's  interest in the Lease, or both, pursuant to Lender's exercise of
any right,  remedy or privilege granted by the Mortgage,  or otherwise at law or
in equity. Without limitation,  Tenant shall attorn to any person or entity that
acquired the Demised Premises pursuant to foreclosure of the Mortgage, or by any
proceeding or voluntary conveyance in lieu of such foreclosure,  or from Lender,
whether by sale,  exchange or  otherwise.  Any  attornment  to anyone other than
Lender shall be conditioned  upon Tenant receiving a  non-disturbance  from such
entity.

     Upon any  attornment  under this  Paragraph 5, the Lease shall  continue in
full force and effect as a direct lease between  Tenant and the person or entity
to whom Tenant attorns, except that such person or entity shall not be:

     (i)  liable for any breach, act or omission of any prior landlord; or

     (ii)  subject to any  offsets,  claims or defenses  which Tenant might have
against any prior landlord; or

     (iii)bound by any rent or additional  rent or other payment in lieu of rent
which Tenant might have paid to any prior  landlord more than 30 days in advance
of its due date  under the Lease or which  such  person or entity  has  physical
possession of; or

     (iv) bound by any  amendment  or  modification  of the Lease  made  without
Lender's written consent, where such consent is required by the Mortgage; or

     (v) bound by any notice  given by Tenant to  Landlord,  whether or not such
notice is given  pursuant to the terms of the Lease,  unless a copy  thereof was
then also given to Lender; or

     (vi) be liable  for any  security  deposit  or other sums held by any prior
landlord, unless actually received.



<PAGE>


The person or entity to whom Tenant  attorns shall be liable to Tenant under the
Lease  only  during  such  person  or  entity's  period of  ownership,  and such
liability shall not continue or survive as to the transferor after a transfer by
such person or entity of its interest in the Lease and the Demised Premises.

     6.   REPRESENTATIONS AND WARRANTIES.

          6.1 Landlord and Tenant each hereby represent and warrant to Lender as
follows regarding the Lease:

     (a) A true and  correct  copy of the Lease  (inclusive  of all  riders  and
exhibits  thereto)  is  attached  to the  counterpart  of this  Agreement  being
delivered   to  Lender.   There  are  no  other  oral  or  written   agreements,
understandings  or the like between  Landlord and Tenant relating to the Demised
Premises or the Lease transaction.

     (b) The term of the Lease is expected  to  commence  on or about  August 1,
1999.

     (c) Under the Lease,  Tenant shall be obligated to pay rent without present
right of defense or offset,  at the rate of $54,818.67  per month.  Rent is paid
through  and  including  N/A , 19__.  No rent has been paid more than 30 days in
advance,  and Tenant has no claim against the Landlord for any deposits or other
sums.

     (d) The Lease has not been modified, altered or amended in any respect.

     (e) All of the  improvements  contemplated  by the Lease have been entirely
completed as required therein.

     (f) The  addresses for notices to be sent to Tenant and Landlord are as set
forth in the Lease.

     (g) To Tenant's knowledge,  Tenant has no right of first refusal, option or
other right to purchase the  Premises or any part  thereof,  including,  without
limitation, the Demised Premises.

     6.2 Several.  Landlord and Tenant severally represent and warrant to Lender
with respect to themselves, but not with respect to the other:

     (a) The execution of the Lease was duly authorized,  the Lease was properly
executed and is in full force and effect and is valid,  binding and  enforceable
against Tenant and Landlord and there exists no monetary default or, to the best
of their  knowledge,  no  non-monetary  default,  nor state of facts  which with
notice, the passage of time, or both, could ripen into a default, on the part of
either Tenant or Landlord.

     (b)  There  has not  been  filed  by or  against  nor,  to the  best of the
knowledge and belief of the representing  party, is there threatened  against or
contemplated  by,  Landlord or Tenant,  a petition in  bankruptcy,  voluntary or
otherwise,  any  assignment for the benefit of creditors,  any petition  seeking
reorganization  or arrangement under the bankruptcy laws of the United States or
of any state thereof, or any other action brought under said bankruptcy laws.


<PAGE>


     (c) There has not been any assignment, hypothecation or pledge of the Lease
or rents accruing  under the Lease,  other than pursuant to the Mortgage and the
Lease Assignment. Tenant makes the representation set forth in this subparagraph
only to its best knowledge and belief.

     7. RENTS.  Landlord and Tenant jointly and severally  acknowledge  that the
Lease  Assignment  provides  for the  direct  payment to Lender of all rents and
other  monies  due and to  become  due to  Landlord  under  the  Lease  upon the
occurrence of certain  conditions as set forth in the Lease  Assignment  without
Lender's  taking  possession  of the  Demised  Premises  or  otherwise  assuming
Landlord's  position  or any of  Landlord's  obligations  under the Lease.  Upon
receipt from Lender of written  notice to pay all such rents and other monies to
or at the direction of Lender, Landlord authorizes and directs Tenant thereafter
to make all such payments to or at the direction of Lender,  releases  Tenant of
any and all  liability  to Landlord  for any and all payment so made,  and shall
defend,  indemnify and hold Tenant harmless from and against any and all claims,
demands,  losses, or liabilities  asserted by, through or under Landlord (except
by Lender) for any and all payments so made. Upon receipt of such notice, Tenant
thereafter  shall pay all monies then due and becoming due from Tenant under the
Lease to or at the  direction of Lender,  notwithstanding  any  provision of the
Lease  to the  contrary.  Tenant  agrees  that  neither  Lender's  demanding  or
receiving any such payments,  nor Lender's  exercising any other right,  remedy,
privilege,  power or immunity  granted by the Mortgage or the Lease  Assignment,
will  operate  to impose  any  liability  upon  Lender  for  performance  of any
obligation of Landlord under the Lease unless and until Lender elects  otherwise
in writing.  Such payments shall continue until Lender directs Tenant  otherwise
in writing.

     Tenant  agrees  not to pay any rent  under the  Lease  more than 30 days in
advance without Lender's consent.  The provisions of this Paragraph 7 will apply
from time to time throughout the term of the Lease.

     8. CURE.  If Tenant  becomes  entitled  to  terminate  the Lease or offset,
withhold or abate rents  because of any default by  Landlord,  then Tenant shall
give Lender written notice specifying Landlord's default. Lender then shall have
the right,  but not the  obligation,  to cure the specified  default  within the
following time periods:

     (a) Fifteen days after receipt of such notice with respect to defaults that
can be cured by the payment of money; or

     (b) Thirty  days after  receipt of such  notice  with  respect to any other
default;  unless the cure  requires  Lender to obtain  possession of the Demised
Premises,  in which case such thirty day period shall not commence  until Lender
acquires  possession,  so long as Lender proceeds promptly to acquire possession
of the Demised  Premises with due  diligence,  by foreclosure of the Mortgage or
otherwise.



<PAGE>


Nothing  contained  in this  Paragraph  8 shall  require  Lender to  commence or
continue any foreclosure or other proceedings, or, if Lender acquires possession
of the Demised Premises, to continue such possession,  if all defaults specified
by Tenant in its notice are cured.  Possession  by a receiver,  or other similar
official  appointed  at the  instance,  or with the  consent,  of  Lender  shall
constitute possession by Lender for all purposes under this Paragraph 8.

     9. ESTOPPEL LETTERS.  Whenever reasonably requested by Lender, Landlord and
Tenant  from time to time  shall  severally  execute  and  deliver  to or at the
direction  of  Lender,  and  without  charge  to  Lender,  one or  more  written
certifications of all of the matters as set forth in Paragraph 6, whether Tenant
has exercised any renewal option or options and any other information the Lender
may reasonably  require to confirm the current  status of the Lease,  including,
without limitation, a confirmation that the Lease is and remains subordinated as
provided in this Agreement.

     10. CASUALTY AND EMINENT DOMAIN.  Landlord and Tenant jointly and severally
agree  that  the  Mortgage  permits  Lender,  at its  option,  to  apply  to the
indebtedness  from time to time secured by the  Mortgage  any and all  insurance
proceeds  payable with respect to any casualty loss at the Demised  Premises and
any  and  all  awards  or  other  compensation  that  may  be  payable  for  the
condemnation  of all or any portion of the  Demised  Premises,  or any  interest
therein,  or  by  way  of  negotiated   settlement  or  conveyance  in  lieu  of
condemnation;  and Landlord and Tenant jointly and severally consent to any such
application by Lender.  Notwithstanding the foregoing, Landlord and Lender agree
that any and all  insurance  or  condemnation  proceeds  payable with respect to
Tenant's property or the interruption or relocation of Tenant's business (except
for rental loss insurance  proceeds) will be paid to Tenant,  so long as they do
not reduce the proceeds otherwise payable to Lender.

     11. NOTICES.  All notices,  demands,  and other communications that must or
may be given or made in connection  with this  Agreement must be in writing and,
unless receipt is expressly  required,  will be deemed  delivered or made 5 days
after  having  been mailed by  registered  or  certified  mail,  return  receipt
requested, or by express mail, in any event with sufficient postage affixed, and
addressed to the parties as follows:

          TO LENDER:  c/o AMRESCO Services, L.P.
                                 235 Peachtree Street, N.E., Suite 900
                                 Atlanta, Georgia  30303
                                 Attn.: Private Sector Servicing

          TO LANDLORD:W9/TIB Real Estate Limited Partnership
                                 c/o Archon Group, L.P.
                                 1275 K Street NW, Suite 900
                                 Washington, DC 20005

          TO TENANT:  Kronos Incorporated
                                 400 Fifth Avenue
                                 Waltham, MA 02151



<PAGE>


Such  addresses  may be changed by notice  pursuant  to this  Paragraph  11; but
notice of change of address is effective only upon receipt.  Landlord and Tenant
jointly and  severally  agree that they will  furnish  Lender with copies of all
notices  relating to the Lease.  All  communications  to Lender shall  reference
"AMRESCO Loan No.: __________ ".

     12.  SUCCESSORS AND ASSIGNS.  As used in this Agreement,  the word "Tenant"
shall mean Tenant and any subsequent  holder or holders of an interest under the
Lease,  as the text may  require,  provided  that the interest of such holder is
acquired in accordance  with the terms and  provisions of the Lease and the word
"Lender"  shall  mean  Lender or any other  subsequent  holder or holders of the
Mortgage or any party acquiring  title to the Demised  Premises by purchase at a
foreclosure sale, by deed of the Lender, or otherwise. Subject to the foregoing,
this  Agreement  shall  bind and inure to the  benefit of  Landlord,  Tenant and
Lender,  their legal  representatives,  successors and assigns. The terms Lease,
Mortgage  and  Lease   Assignment   shall   include  any  and  all   amendments,
modifications, replacements, substitutions, extensions, renewals and supplements
thereto.

     13. FURTHER ASSURANCES. Landlord and Tenant from time to time shall execute
and  deliver at  Lender's  request  all  instruments  that may be  necessary  or
appropriate  to evidence  their  agreement  hereunder  provided such  instrument
neither increases Tenant's obligations or decreases its rights under the Lease.

     14.   COUNTERPARTS.   This  Agreement  may  be  executed  in  one  or  more
counterparts,   each  of  which  shall  be  deemed  an  original  and  all  such
counterparts shall constitute one and the same instrument.

     15.  SEVERABILITY.  A determination that any provision of this Agreement is
unenforceable or invalid shall not affect the  enforceability or validity of any
other provision,  and any determination that the application of any provision of
this Agreement to any person or to any person or to particular  circumstances is
illegal or unenforceable shall not affect the enforceability or validity of such
provision as it may apply to other persons or circumstances.


<PAGE>


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

LENDER:

LASALLE NATIONAL BANK, as Trustee for GS Mortgage  Securities  Corporation II 
Commercial  Mortgage  Pass-Through  Certificates,  Series
1998-GSFL1

By:  AMRESCO Services, L.P.,
     its authorized agent

     By:  AMRESCO Mortgage Capital, Inc.,
          its general partner

          By:_____________________________
              Name:___________________________
              Title:  Servicing Officer

LANDLORD:

W9/TIB REAL ESTATE LIMITED
PARTNERSHIP, a Delaware limited partnership

By:  W9/TIB Gen-Par, Inc., a Delaware
          corporation, its general partner

          By:                                  
              Name:                                
              Title:                               

TENANT:

KRONOS INCORPORATED, a Massachusetts corporation

By:                                         
    Name:                                   
    Title:                                  


<PAGE>


STATE OF ____________      )
                                    )
COUNTY OF __________       )        _____________ ___, 1999

         Then         personally         appeared        the         above-named
_________________________________, __________________________________ of AMRESCO
Mortgage  Capital,  Inc.,  as  general  partner of AMRESCO  Services,  L.P.,  as
authorized  agent  for  LaSalle  National  Bank,  as  Trustee  for  GS  Mortgage
Securities Corporation II Commercial Mortgage Pass-Through Certificates,  Series
1998-GSFL1, and acknowledged the foregoing instrument to be his/her free act and
deed and the free act and deed of Bankers  Trust  Company of  California,  N.A.,
before me,

                                     ------------------------------------
                                     (Seal)
                                     Notary Public
                                     My commission expires:

STATE OF ____________      )
                                    )
COUNTY OF __________       )        _____________ ___, 1999

         Then         personally         appeared        the         above-named
_________________________________,  __________________________________ of W9/TIB
Gen-Par, Inc., as General Partner of W9/TIB Real Estate Limited Partnership, and
acknowledged the foregoing  instrument to be his/her free act and deed, the free
act and deed of W9/TIB  Gen-Par,  Inc., and the free act and deed of W9/TIB Real
Estate Limited Partnership, before me,

                                     ------------------------------------
                                      (Seal)
                                      Notary Public
                                      My commission expires:

STATE OF ____________      )
                                    )
COUNTY OF __________       )        _____________ ___, 1999

         Then         personally         appeared        the         above-named
_________________________________,  __________________________________ of Kronos
Incorporated,  and acknowledged the foregoing  instrument to be his/her free act
and deed and the free act and deed of Kronos Incorporated, before me,

                                     ------------------------------------
                                      (Seal)
                                      Notary Public
                                      My commission expires:


<PAGE>



                                       K-3

                                    EXHIBIT K

                       RIGHT OF FIRST OFFER RE 4 OMNI WAY

         Subject to the rights of existing  tenants to continue to occupy  their
respective  premises and to any now or hereafter  arising extension or expansion
options of other tenants, provided no Event of Default then exists, and provided
Tenant has a net worth equal to or greater  than  ninety-five  percent  (95%) of
Tenant's  net worth as of the date hereof,  Landlord  shall,  after  receiving a
formal request for proposal to which Landlord elects to respond (other than from
the  then-current  tenant  therein),  first  offer to lease to Tenant  the space
designated on page 2 of this Exhibit (the "4 Omni Way Offer Space");  such offer
shall be in writing and specify the market  lease terms for the 4 Omni Way Offer
Space, including a lease term of at least five (5) years, the Fair Market Rental
Value (as  determined in  accordance  with Exhibit G above) to be paid for the 4
Omni Way Offer  Space and the date on which the 4 Omni Way Offer  Space shall be
available  for  lease  (the "4 Omni Way  Offer  Notice").  Tenant  shall  notify
Landlord in writing  whether  Tenant elects to lease the entire 4 Omni Way Offer
Space on the terms set forth in the 4 Omni Way Offer  Notice,  within  seven (7)
business days after Landlord  delivers to Tenant the 4 Omni Way Offer Notice. If
Tenant  timely  elects to lease the 4 Omni Way Offer  Space,  then  Landlord and
Tenant shall, at Landlord's sole  discretion,  execute a new lease agreement for
the 4 Omni Way Offer Space or an amendment to this Lease within thirty (30) days
after Tenant's election,  effective as of the date the 4 Omni Way Offer Space is
available for lease,  on the terms set forth in the 4 Omni Way Offer Notice and,
to the extent not inconsistent with the 4 Omni Way Offer Notice terms, the terms
of this Lease.

         If Tenant fails or is unable to timely  exercise  its right  hereunder,
then such right  shall  lapse,  time being of the  essence  with  respect to the
exercise  thereof,  and  Landlord  may lease all or a portion  of the 4 Omni Way
Offer   Space  to  third   parties  on  such  terms  as   Landlord   may  elect.
Notwithstanding  the foregoing,  if Landlord  leases less than one-half of the 4
Omni Way Offer Space to a third  party,  Tenant's  right of first offer  granted
under this Exhibit  shall  continue  with respect to the remainder of the 4 Omni
Way Offer Space not leased to such third  party;  provided,  however,  if Tenant
fails or is unable to timely  exercise its rights  hereunder with respect to the
remainder of the 4 Omni Way Offer Space,  then such right to lease the remainder
of the 4 Omni Way Offer  Space  shall  lapse,  time  being of the  essence  with
respect to the exercise thereof,  and Landlord may lease all or a portion of the
remainder  of the 4 Omni  Way  Offer  Space to third  parties  on such  terms as
Landlord may elect.  Further,  but subject to the  provisions  of the  preceding
sentence,  Tenant's right of first offer granted under this Exhibit with respect
to the 4 Omni Way Offer Space shall continue during the initial Term on the same
terms and  conditions  set forth herein to the extent the 4 Omni Way Offer Space
again becomes available during the initial Term.



<PAGE>


         Tenant may not  exercise  its rights  under this Exhibit if an Event of
Default exists,  if Tenant is not then occupying at least  seventy-five  percent
(75%)  of  the  Premises,  or if  Tenant  has a net  worth  that  is  less  than
ninety-five  percent  (95%) of  Tenant's  net worth as of the date  hereof.  For
purposes hereof,  if a 4 Omni Way Offer Notice is delivered for less than all of
the 4 Omni Way Offer Space but such notice  provides for an expansion,  right of
first  refusal,  or other  preferential  right to  lease  some of the  remaining
portion of the 4 Omni Way Offer Space, then such remaining portion of the 4 Omni
Way Offer  Space  shall  thereafter  be  excluded  from the  provisions  of this
Exhibit.

         Tenant's rights under this Exhibit shall terminate if (a) this Lease or
Tenant's right to possession of the Premises is  terminated,  (b) Tenant assigns
any of its interest in this Lease or sublets more than twenty-five percent (25%)
of the Premises, or (c) the initial Term expires.

         Notwithstanding  any  provisions of this Lease to the contrary,  if the
fee title to the 4 Omni Way Offer Space is held by an entity other than Landlord
or any Affiliate of Landlord and such entity fails to comply with the provisions
of this  Exhibit K, Tenant shall have no  recourse,  rights or remedies  against
Landlord if such entity  fails to comply with the  provisions  of this Exhibit K
and Tenant shall continue to comply with the provisions of this Lease.


<PAGE>


                       DEPICTION OF 4 OMNI WAY OFFER SPACE

                          (4 Omni Way, Chelmsford, MA)

Lot 2B as shown on that certain plan  entitled  "Plan of Land of Billerica  Road
Site, Chelmsford,  MA", which plan is recorded with the Middlesex North District
Registry of Deeds in Plan Book 143 as Plan 143.


<PAGE>



                                       vi

                              LIST OF DEFINED TERMS

                                                                         Page

Additional Rent.............................................................2
Affiliate         25
Affiliate of Tenant.........................................................13
Affiliated Buildings........................................................19
AS-IS             D-1
Base Building Electrical Capacity............................................8
Basic Rent        1
Building          1
Building Holidays 7
Building's Structure.........................................................8
Casualty          17
Commencement Date 1
Construction Allowance.....................................................D-2
Damage Notice     17
Environmental Reports...................................................26, 30
Event of Default  18
Fair Market Rental Value...................................................G-1
GAAP              2
Hazardous Materials.........................................................25
including         25
Interest Rate     5
Landlord          1
Landlord's Mortgagee........................................................15
Law               25
Laws              25
Lease             1
Lease Year        1
Letter of Credit  5
Loss              14
Mortgage          15
Offer Notice      K-1
Offer Space       K-1
Operating Costs   2
Operating Costs and Tax Statement............................................4
Parking Area      E-1
Permitted Use     12
Premises          1
Rent              2
Rooftop Equipment 27
Security Deposit  5


<PAGE>


Taking......................................................................16
Taxes             3
Tenant            1, 19
Tenant Party      25
Term              1
Total Construction Costs...................................................D-2
Transfer          12
Work              D-1
Working Drawings  D-1