Document:

NET LEASE
                             BASIC LEASE INFORMATION

DATE:              October 30, 1998

LANDLORD:          The Multi-Employer Property Trust, a trust organized under 12
                   C.F.R. Section 9.18

TENANT:            Certicom Corp., a Delaware corporation

PREMISES:          All  of the  Building  located  at  25801  Industrial  Blvd.,
                   Hayward, California

PROPERTY:          Mt. Eden Business Park, Hayward, California

USE:               General  Office  and   Administrative   Purposes,   including
                   computer hardware and software development

TERM:              Approximately Seven (7) Years

ESTIMATED COMMENCEMENT DATE:            January 15, 1999

INITIAL BASE RENT:                      $53,568.75

TENANT'S PERCENTAGE SHARE:              100%

SECURITY DEPOSIT:                       $75,000   &  Letter  of  Credit
                                        described in Section 17

GUARANTOR:                              Certicom Corp. an Ontario corporation

BROKERS:       CB   Commercial   Real  Estate   Group  Inc.;   Colliers   Parish
               International Inc; Presco

ADDRESS FOR NOTICES: Landlord:          The Multi-Employer Property Trust
                                        c/o Riggs & Company
                                        808 17th Street N.W.
                                        Washington, D.C. 20006
                                        Attn: Patrick O. Mayberry

                       Tenant:          Certicom Corp.
                                        200 Matheson Blvd. W
                                        Mississauga, Ontario
                                        Canada L5R 3L7

      After Commencement Date:          To Tenant at the Premises

LANDLORD'S CONTRIBUTION
TO TENANT IMPROVEMENTS:                 $857,100.00

LANDLORD'S INITIALS:                    TENANT'S INITIALS:

          M??                                BM
-----------------------                 ---------------------------

<PAGE>

                                TABLE OF CONTENTS
                                                                            Page
                                                                            ----

  1.  Premises.                                                               1
  2.  Term.                                                                   1
  3.  Rent                                                                    1
  4.  Base Rent                                                               2
  5.  Operating Expenses                                                      2
  6.  Proration of Rent                                                       4
  7.  Tenant Improvements                                                     4
  8.  Use of the Premises                                                     5
  9.  Alterations                                                             7
 10.  Repairs                                                                 8
 11.  Damage or Destruction                                                   8
 12.  Eminent Domain                                                          9
 13.  Indemnity and Insurance                                                10
 14.  Assignment or Sublet                                                   12
 15.  Default                                                                15
 16.  Landlord's Right to Perform Tenant's Covenants                         16
 17.  Security Deposit; Letter of Credit                                     16
 18.  Surrender of Premises                                                  18
 19.  Holding Over                                                           18
 20.  Access to Premises                                                     19
 21.  Signs                                                                  19
 22.  Subordination                                                          20
 23.  Transfer of the Property                                               20
 24.  Estoppel Certificates; Financial Statements                            21
 25.  Mortgagee Protection                                                   21
 26.  Attorney's Fees                                                        21
 27.  Brokers                                                                21
 28.  Parking                                                                22
 29.  Utilities and Services                                                 22
 30.  Intentionally Deleted                                                  22
 31.  Acceptance                                                             22
 32.  Use of Building Name                                                   22
 33.  Recording                                                              23
 34.  Quitclaim                                                              23
 35.  Notices                                                                23
 36. Landlord's Exculpation                                                  23
 37. Additional Structures                                                   23
 38. Consents and Approvals                                                  24
 39. General                                                                 24
 40. Renewal Option                                                          25

EXHIBIT "A": Premises and Business Park Site Plan
EXHIBIT "B": Tenant Improvements
EXHIBIT "C": Commencement Date Memorandum
EXHIBIT "D": Rules and Regulations
EXHIBIT "E": Form of Tenant Estoppel Certificate
EXHIBIT "F": Appraisal Procedure

<PAGE>

                                    NET LEASE

     THIS LEASE,  which is effective as of the date set forth in the Basic Lease
Information,  is entered by Landlord and Tenant, as set forth in the Basic Lease
Information.  Terms which are  capitalized in this Lease shall have the meanings
set forth in the Basic Lease Information.

1. Premises.

     Landlord  leases to Tenant,  and Tenant leases from Landlord,  the Premises
described in the Basic Lease  Information (as shown on Exhibit A), together with
the right in common to use the Common  Areas.  The Common  Areas  shall mean the
areas and facilities  within the land shown on Exhibit A (the "Land") and within
the Building  identified in the Basic Lease  Information  (the  "Building")  and
within all other  buildings  and  improvements  now or hereafter  located on the
Land,  provided and  designated by Landlord for the general use,  convenience or
benefit  of Tenant  and other  tenants  and  occupants  of the  Property  (e.g.,
restrooms;  janitorial,  telephone and electrical closets; sidewalks; driveways,
public lobbies,  entrances and stairs; and unreserved parking areas). The Common
Areas shall include the Cultural  Center  delineated on Exhibit A (the "Cultural
Center"); provided, however, that Landlord may from time to time prescribe rules
and regulations for use of and access to the Cultural Center by Tenant and other
tenants of the Property.  Without limitation of the provisions of any such rules
and  regulations,  Tenant  acknowledges  that  (i) no  tenant  of  the  Property
(including Tenant) shall have exclusive rights to use the Cultural Center,  (ii)
on up to ten (10) occasions each calendar year some or all of the tenants of the
Property  (including  Tenant) may be excluded  from use of the Cultural  Center,
(iii) access to the Cultural  Center  shall be  restricted  by means of a locked
gate or other apparatus daily from 6:00 p.m. to 8:00 a.m.  Landlord reserves the
right to make changes to the Common Areas. The Building and such other buildings
and improvements now or hereafter located on the Land are collectively  referred
to in this Lease as the  "Buildings".  The Land,  the  Buildings  and the Common
Areas are collectively  referred to in this Lease as the "Property" or the "Real
Property".

2. Term.

     a. Lease Term.  The term of this Lease (the "Term")  shall  commence on the
date (the  "Commencement  Date")  which is the later to occur of (x) January 15,
1999, or (y)  Substantial  Completion of the Tenant  Improvements.  "Substantial
Completion of the Tenant Improvements" shall be deemed to have occurred when the
Tenant  Improvements (as defined in Exhibit B) have been completed in accordance
with Final Plans (as defined in Exhibit B),  subject only to the  completion  or
correction  of Punch List Items.  "Punch List Items"  shall mean  incomplete  or
defective work or materials in the Tenant  Improvements  which do not materially
impair  Tenant's  use of the  Premises  for the  conduct  of  Tenant's  business
therein.  The Term shall end on the last day of the calendar  month in which the
seventh  (7th)  annual   anniversary  of  the  Commencement   Date  occurs  (the
"Expiration Date").  Notwithstanding the foregoing,  if the Commencement Date is
delayed due to Tenant  Delay (as  defined in Exhibit  B),  then for  purposes of
determining  the  commencement  of  Tenant's  obligation  to pay  Base  Rent and
Operating  Expenses  pursuant to Sections 4 and 5 below, the  Commencement  Date
shall be deemed accelerated by the period of Tenant Delay.

     b. Premises Not Delivered.  If, for any reason,  the Commencement Date does
not occur by the Estimated  Commencement  Date, the failure shall not affect the
validity of this  Lease,  or the  obligations  of Tenant  under this Lease,  and
Landlord shall not be subject to any liability.

     c. Commencement Date Memorandum. When  the Commencement Date is determined,
the parties shall execute a Commencement  Date Memorandum,  in the form attached
hereto as Exhibit C,  setting  forth the  Commencement  Date and the  Expiration
Date.

     d. Early  Entry.  If Tenant is  permitted by Landlord to enter the Premises
prior to the Commencement Date for the purpose of fixturing or any purpose other
than the conduct of Tenant's business, the entry shall

                                       1
<PAGE>

be subject to all the terms and  provisions of this Lease,  except that Tenant's
obligation to pay Base Rent and Operating  Expenses shall not commence until the
Commencement Date. Without limitation, in no event will Landlord consent to such
early access if Landlord shall reasonably determine that the same might delay or
interfere with Landlord's  construction of the Tenant Improvements,  or increase
the cost of the Tenant Improvements.

3. Rent.

     As used in this Lease,  the term "Rent" shall  include:  (i) the Base Rent;
(ii) Operating Expenses payable by Tenant pursuant to Section 5 below; and (iii)
all  other  amounts  which  Tenant is  obligated  to pay under the terms of this
Lease.  All amounts of money payable by Tenant to Landlord shall be paid without
prior notice or demand,  deduction or offset. If any installment of Base Rent is
not paid by Tenant by the fifth  (5th) day of the  month,  or if any  payment of
Operating Expenses or any other amount payable by Tenant is not paid within five
(5) days of the due date  thereof,  Tenant  shall pay to Landlord a late payment
charge  equal to five percent (5%) of the amount of the  delinquent  amount,  in
addition  to the amount of Rent then  owing,  regardless  of whether a notice of
default or notice of termination has been given by Landlord.  In addition to the
five  percent  (5%) late  charge,  any Base Rent,  Operating  Expenses  or other
amounts owing  hereunder  which are not paid within five (5) days after the date
they are due shall thereafter bear interest at the rate ("Interest  Rate") which
is the lesser of eighteen  percent (18%) per annum or the maximum rate permitted
by applicable  law.  Notwithstanding  the foregoing,  Landlord shall give Tenant
notice of  non-payment  and three (3) days from  receipt of such  notice to cure
such  non-payment  twice in any calendar  year before  assessing  such late fees
and/or interest in such calendar year.

4. Base Rent.

     a. Initial Base Rent.  Commencing on the Commencement  Date, and thereafter
on the first day of each calendar month of the Term,  Tenant shall pay Base Rent
to Landlord (or other entity designated by Landlord),  in advance, at Landlord's
address for notices  (as set forth in the Basic  Lease  Information)  or at such
other  address as Landlord  may  designate.  The Initial  Base Rent shall be the
amount set forth in the Basic Lease Information. Base Rent payable hereunder for
the first  full  calendar  month  after  Tenant's   obligation  to pay Base Rent
commences shall be paid upon Tenant's execution of this Lease.

     b.  Base  Rent  Adjustment.  Commencing  on the  first day of the 37th full
calendar  month of the Term,   the Base Rent shall  increase to  $56,831.09  per
month,  and shall be payable  in such  amount  through  the end of the 60th full
calendar  month of the  Term.  Commencing  on the  first  day of the  61st  full
calendar  month of the Term,  the Base Rent shall  increase  to  $60,292.10  per
month, and shall be payable in such amount through the Expiration Date.

5. Operating Expenses.

     a.  Operating  Expenses.  Tenant  shall pay  Tenant's  Percentage  Share of
Operating  Expenses  incurred by Landlord  during each  calendar year falling in
whole or in part during the Term.

     b. Operating  Expenses.  The term  "Operating  Expenses"  shall include all
reasonable  expenses  and costs of every kind and nature,  except as provided in
the next paragraph,  which Landlord shall pay or become obligated to pay because
of or in connection with the ownership, management, administration, maintenance,
repair and operation of the Premises,  the  Buildings,  the Common Areas and the
balance of the  Property,  to the extent  allocable to the Building in which the
Premises is located.  The allocation of Operating Expenses to the Building shall
be made on the same ratio that the rentable square footage of the Building bears
to the aggregate  rentable  square footage of all buildings in the Business Park
(assuming for such purpose that all buildings in the Business  Park, as shown on
Exhibit A attached hereto, are fully  constructed);  except where Landlord shall
reasonably determine, for good cause, that the nature of any given

                                       2
<PAGE>

Operating  Expense requires that it be allocated in another  reasonable  manner.
Operating Expenses shall include,  without  limitation,  the following:  (i) all
impositions  relating to the Real  Property,  including  Real Property Taxes (as
defined in Section  5.d.);  (ii)  premiums  for  insurance  relating to the Real
Property,  including  as set forth in  Sections  13.b.,  13.d.  and  13.i.,  and
insurance  deductibles  paid by  Landlord;  (iii) wages,  salaries,  bonuses and
expenses and benefits (including hospitalization,  medical, surgical, retirement
plan, pension plan, union dues, life insurance,  including group life insurance,
welfare and other fringe benefits, and vacation, holidays and other paid absence
benefits,  and costs of  uniforms)  of all on-site  and  off-site  employees  of
Landlord or its  agents,  a the rank of  property  manager or below,  engaged in
operation, management,  administration,  maintenance, repair and security of the
Real Property,  including,  without limitation,  administrative,  management and
accounting  personnel and the  individual(s)  responsible  for management of the
Property, and payroll, social security, workers' compensation,  unemployment and
similar taxes with respect to such employees of Landlord or its agents,  and the
cost of providing disability or other benefits imposed by law or otherwise, with
respect to such employees;  (iv) costs of all supplies,  materials and equipment
rentals  used in  operations;  (v) all  maintenance,  janitorial,  security  and
service costs; (vi) a management fee not to exceed 4% of all gross revenues from
the Real  Property,  including  revenues  attributable  to  Tenant's  and  other
tenants' payments of Operating  Expenses;  (vii) legal and accounting  expenses,
including the cost of audits by certified public accountants; (viii) all repair,
painting  and  maintenance  costs  relating to the Real  Property and its Common
Areas,  including  sidewalks,  landscaping,  service  areas,  mechanical  rooms,
parking  areas,  Building  exterior  and  driveways;  (ix) all charges for heat,
water, gas, steam, fuel, electricity and other utilities used or consumed in the
Buildings  and Common  Areas;  (x) costs of repairs,  replacements,  and general
maintenance to and of the Building Systems and the Base Building  Components (as
such terms are defined in Sections 9.a. and 10.a.;   respectively,  below); (xi)
the  costs of  capital  improvements,  capital  replacements,  capital  repairs,
capital  equipment,  and  capital  tools and  devices  installed  or paid for by
Landlord and intended to reduce other  Operating  Expenses or required to comply
with Legal  Requirements  (as defined in Section 8.c. below) or intended for the
protection of the health and safety of the occupants of the Property;  and (xii)
Landlord's  costs of  maintaining  the  Cultural  Center,  which  costs shall be
deemed, for purposes of this Lease, the sum of $60,000.00,  as such sum shall be
increased  on  January 30,  1999 and  each  January  30th  thereafter (each,  an
"Adjustment  Date"),  by the  percentage  increase in the Index over the one (1)
year  period  ending on the date on which the  Index is  published  in the month
immediately preceding the Adjustment Date. With respect to any costs included in
Operating  Expenses  under  clause  (x)  which  are  capital  expenditures,   as
determined  by  Landlord  in  accordance  with  generally  accepted   accounting
principles consistently applied, and with respect to the costs of items included
in Operating  Expenses  under clause (xi),  such costs shall be amortized over a
period determined by Landlord, together with interest on the unamortized balance
at a rate per annum equal to three (3) percentage  points over the Treasury Rate
charged at the time such item is constructed or acquired, or at such higher rate
as may have been paid by Landlord on funds borrowed for the purpose of acquiring
or  constructing  such item,  but in either case not more than the maximum  rate
permitted  by law at the time  such item is  acquired  or  constructed.  As used
herein,  "Treasury Rate" means the six-month United States treasury bill rate in
effect  from time to time by the San  Francisco  Main Office of Bank of America,
NT&SA (or any successor  bank  thereto),  or if there is no such rate,  the rate
quoted  by such bank in  pricing  ninety  day  commercial  loans to  substantial
commercial borrowers.

         The term "Index" as used herein shall mean the Consumer Price Index for
All Urban Consumers (1982-84 = 100) San Francisco-Oakland-San  Jose, California,
All Items, published by the Bureau of Labor Statistics of the U.S. Department of
Labor. If the Bureau of Labor  Statistics  ceases to publish the above Index, or
if the above Index is otherwise renamed, discontinued or superseded, the parties
agree that the Bureau of Labor Statistics or any successor  governmental  agency
thereto will be the sole judge of the comparability of successive  indexes,  but
if no succeeding index is published,  the calculations under this Lease based on
the Index  shall be made using the most  closely  comparable  statistics  on the
purchasing power of the consumer dollar as published by a responsible  financial
authority and selected by Landlord.

                                       3
<PAGE>

         Operating Expenses shall not include the following: (i) depreciation on
the Buildings or equipment or systems therein;  (ii) debt service;  (iii) rental
under any ground or underlying lease; (iv) attorneys' fees and expenses incurred
in  connection  with  lease  negotiations  or  disputes  with  past,  current or
prospective Building tenants;  (v) the cost of decorating,  improving for tenant
occupancy,  painting or redecorating  portions of the Buildings to be demised to
tenants;  (vi)  advertising  expenses;   (vii)  costs  reimbursed  by  insurance
proceeds; or (viii) real estate broker's or other leasing commissions.

         The  parties  agree that  statements  in this Lease to the effect  that
Landlord is to perform certain of its  obligations  hereunder at its own or sole
cost  and/or  expense  shall  not be  interpreted  as  excluding  any cost  from
Operating Expenses if such cost is an Operating Expense pursuant to the terms of
this Section 5.b.

   c. Monthly Increments; Adjustment. Promptly following the commencement of the
Term and prior to the commencement of each subsequent  calendar year (or as soon
thereafter as  practicable),  Landlord  shall  estimate the  Operating  Expenses
payable by Tenant for such calendar year pursuant to this Section.  Tenant shall
pay to Landlord, on the first day of each month, in advance,  one-twelfth (1/12)
of  Landlord's  estimated  amount.  If at any time during the course of the year
Landlord determines that the Operating Expenses payable by Tenant will vary from
the then estimated  amount,  by notice to Tenant  Landlord may revise the amount
payable by Tenant  during the balance of the  calendar  year such that the total
estimated  additional  amount due from Tenant for such  calendar year is paid by
Tenant during the balance of the calendar year in equal monthly amounts.  Within
ninety (90) days (or as soon thereafter as practicable)  after the close of each
calendar year, Landlord shall provide Tenant with a statement to account for any
difference  between  the actual and the  estimated  Operating  Expenses  for the
previous  year.  Landlord's  annual  statement  shall be final and binding  upon
Landlord and Tenant unless,  within ninety (90) days after  delivery  thereof to
Tenant,  Landlord  shall  revise or Tenant  shall  contest  any item  therein by
written notice to the other,  specifying  each item revised or contested and the
reason therefor. Notwithstanding the foregoing, the Real Property Taxes included
in any such annual  statement  may be modified by any  subsequent  adjustment or
retroactive  application  of Real Property  Taxes  affecting the  calculation of
Operating  Expenses.  If Tenant has overpaid  the amount of  Operating  Expenses
owing pursuant to this Section,  Landlord shall credit the  overpayment  against
Tenant's  next  payments due under this Section 5. If Tenant has  underpaid  the
amount of Operating  Expenses owing  pursuant to this Section,  Tenant shall pay
the  amount of the  underpayment  to  Landlord  within  thirty  (30) days  after
Tenant's  receipt  of  Landlord's  statement.  If all of  the  buildings  in the
Business  Park  shown on Exhibit A  attached  hereto  are not fully  constructed
during any calendar  year, or if the rentable  area of all such  buildings or of
the Building is not fully occupied during any calendar year,  Operating Expenses
for such calendar year shall be adjusted to equal Landlord's reasonable estimate
of the Operating  Expenses  which would have been incurred  during such calendar
year if all  buildings  in the  Business  Park  were  constructed  and the total
rentable area of all such  buildings and the Building  were  occupied,  and such
adjusted  Operating  Expenses  shall be allocated to the Building as provided in
Section 5.b. above.

     d. Definition of Real Property Taxes.  The term "Real Property Taxes" shall
mean any ordinary or  extraordinary  form of assessment  or special  assessment,
license fee, rent tax, levy, penalty (if a result of Tenant's  delinquency),  or
tax  (other  than net  income,  estate,  succession,  inheritance,  transfer  or
franchise  taxes),  imposed by any authority having the direct or indirect power
to tax, or by any city, county,  state or federal govermnent for any maintenance
or improvement or other district or division thereof. The term shall include all
transit charges, housing fund assessments, real estate taxes and all other taxes
relating to the Premises, Building and/or Property, all other taxes which may be
levied in lieu of real estate taxes, all assessments,  assessment bonds, levies,
fees, and other governmental charges (including, but not limited to, charges for
traffic  facilities,  improvements,  child  care,  water  services  studies  and
improvements,  and fire services studies and improvements) for amounts necessary
to be  expended  because of  govemmental  orders,  whether  general or  special,
ordinary  or  extraordinary,  unforeseen  as well as  foreseen,  of any kind and
nature for public  improvement,  services,  benefits or any other purposes which
are  assessed,  levied,  confirmed,  imposed or become a lien upon the Premises,
Building or Property or become payable during the Term.

                                       4
<PAGE>

     e.  Acknowledgment  of Parties.  It is  acknowledged by Landlord and Tenant
that  Proposition 13 was adopted by the voters of the State of California in the
June, 1978 election,  and that assessments,  taxes, fees, levies and charges may
be  imposed by  governmental  agencies  for such  purposes  as fire  protection,
street, sidewalk, road, utility construction and maintenance, refuse removal and
for other  governmental   services which formerly may have been provided without
charge to property owners or occupants.  It is the intention of the parties that
all new and  increased  assessments,  taxes,  fees,  levies and  charges  due to
Proposition  13 or any other cause are to be included  within the  definition of
Real Property Taxes for purposes of this Lease.

     f. Taxes on Tenant Improvements and  Personal Property. Notwithstanding any
other provision hereof, Tenant shall pay the full amount of any increase in Real
Property  Taxes  during  the Term  resulting  from any and all  Alterations  (as
defined in Section 9.a. below) of any kind whatsoever placed in, on or about the
Premises for the benefit of, at the request of, or by Tenant.  Tenant shall pay,
prior to  delinquency,  all taxes assessed or levied against  Tenant's  personal
property, equipment,  furniture or fixtures (collectively,  "Personal Property")
in, on or about the  Premises.  When  possible,  Tenant shall cause its Personal
Property to be assessed and billed separately from the real or personal property
of Landlord.  Tenant recognizes that pursuant to Section 107.6 of the California
Revenue and Taxation Code Tenant's  possessory  interest under this Lease may be
subject  to  property  taxation  based on the full cash  value,  as  defined  in
Sections 110 and 110.1 of the California Revenue and Taxation Code.

     g.  Fiscal  Year.  Landlord  shall have the right to  account  and bill for
Operating Expenses on the basis of a fiscal year, rather than a calendar year as
set forth above, and to revise such fiscal year from time to time, provided that
Landlord follows generally accepted accounting  principles  consistently applied
in connection therewith.

     h. Net  Lease.  This  shall be a Net Lease  and Base Rent  shall be paid to
Landlord  absolutely  net of all costs and expenses  except as expressly  herein
provided.  The provisions for Tenant's  payment of Tenant's  Percentage Share of
Operating  Expenses are intended to pass on to Tenant and reimburse Landlord for
Tenant's  Percentage  Share of all costs and expenses  associated  with the Real
Property, except as expressly provided in this Lease.

6.  Proration  of  Rent.  If the  Commencement  Date is not the  first  day of a
calendar  month,  or if the end of the Term is not the  last  day of a  calendar
month, Base Rent payable by Tenant pursuant to Section 4, and Operating Expenses
payable by Tenant  pursuant  to Section 5, shall be  prorated  on a daily  basis
(based upon a thirty (30) day month) for such fractional  month. The termination
of this Lease shall not affect the  obligations of Landlord and Tenant  pursuant
to Section 5.c. which are to be performed after the termination.

7. Tenant Improvements. Landlord agrees to construct within the Premises certain
improvements to the Premises  ("Tenant  Improvements")  pursuant to the terms of
Exhibit B. Subject to completion of the Tenant Improvements (including,  without
limitation,  the Punch List Items with respect  thereto), the Premises  shall be
delivered to Tenant in its then "as-is"  condition,  and Landlord shall not have
any obligation to make or pay for any  alterations,  additions,  improvements or
repairs to prepare the Premises for Tenant's occupancy.  The foregoing shall not
relieve  Landlord from  responsibility  for correcting any latent defects in the
construction of the Tenant Improvements, provided that written notice thereof is
given by Tenant to Landlord within one (1) year from the Commencement Date.

8. Use of the Premises.

     a. Use.  The  Premises  shall be used  solely  for the use set forth in the
Basic Lease Information and for no other use or purpose.  Tenant shall not do or
suffer  or  permit  anything  to be done in or about  the  Premises  or the Real
Property  which will in any way obstruct or  interfere  with the rights of other
tenants or occupants  of the Building or injure or annoy them,  or use or suffer
or permit the  Premises to be used for any  immoral,  unlawful or  objectionable
purpose, nor shall Tenant cause, maintain, suffer or permit any nuisance

                                       5
<PAGE>

in,  on or  about  the  Premises  or the Real  Property.  Without  limiting  the
foregoing,  Tenant shall not permit any odors,  smoke,  dust,  gas,  substances,
noise or vibration to emanate from the Premises,  and no  loudspeakers  or other
similar device which can be heard outside the Premises shall,  without the prior
written approval of Landlord, be used in or about the Premises. Tenant shall not
commit  or suffer to be committed any waste in, to or about the Premises. Tenant
agrees  not to  employ  any  person,  entity or  contractor  for any work in the
Premises  (including moving Tenant's equipment and furnishings in, out or around
the Premises)  whose  presence may give rise to a labor or other  disturbance in
the Building  and, if necessary  to prevent such a  disturbance  in a particular
situation, Landlord may require Tenant to employ union labor for the work.

     b. Rules and  Regulations:  CC&R's.  Tenant shall comply with the Rules and
Regulations  attached hereto as Exhibit D, as the same may be modified from time
to time by Landlord  upon prior  notice to Tenant (the  "Rules"),  to the extent
Landlord the Rules are not in conflict with the other  provisions of this Lease.
In addition, Tenant shall comply with any covenants, conditions and restrictions
("CC&R's")  applicable  to the Real  Property,  and all rules,  regulations  and
restrictions  imposed by any association  formed pursuant to the CC&R's, in each
case to the extent  Landlord has delivered a copy thereof to Tenant and the same
are not in conflict with the provisions of this Lease.

     c. Compliance. Tenant shall not permit the Premises to be used in violation
of or in conflict with,  and at its sole cost and expense shall promptly  comply
with, all laws,  statutes,  ordinances and  governmental  rules,  regulations or
requirements  now in  force  or  which  hereinafter  may be in  force,  with the
requirements  of any board of fire  underwriters  or other  similar board now or
hereafter  constituted,  with any  direction  or  occupancy  certificate  issued
pursuant to any law by any public officer or officers, as well as the provisions
of all  recorded  documents  affecting  the  Premises  (all  of  the  foregoing,
collectively, "Legal Requirements"),  insofar as any thereof relate to or affect
the  condition,  use or occupancy of the Premises,  and Tenant shall perform all
work to the Premises and other portions of the Real Property  required to effect
such compliance (or, at Landlord's  election,  Landlord may perform such work at
Tenant's expense).  The judgement of any court of competent  jurisdiction or the
admission of Tenant in any actions against Tenant,  whether  Landlord be a party
thereto or not,  that Tenant has so violated any such law,  statute,  ordinance,
rule,  regulation  or  requirement,  shall be  conclusive  of such  violation as
between Landlord or Tenant.

         In no event shall the foregoing, or any other provisions of this Lease,
impose any  obligation or liability upon Tenant to perform any work or otherwise
remedy any  non-compliant  condition  to the extent that such work or  condition
arises by reason of Landlord's failure to construct the Tenant  Improvements and
Landlord's  Work  (as  defined  in  Exhibit  B) in  compliance  with  all  Legal
Requirements.

     d. Hazardous Materials.  Tenant shall not cause or permit the storage, use,
generation,  release,  handling or disposal  (collectively,  "Handling")  of any
Hazardous  Materials  (as defined  below),  in, on, or about the Premises or the
Real  Property  by  Tenant or any  agents,  employees,  contractors,  licensees,
subtenants,  customers guests or invitees of Tenant  (collectively  with Tenant,
"Tenant Parties"),  except that Tenant shall be permitted to use in the Premises
in a normal  and  customary  manner  normal  quantities  of office  supplies  or
products (such as copier fluids or cleaning  supplies)  customarily  used in the
conduct of general  business  office  activities  ("Common  Office  Chemicals"),
provided that the Handling of such Common Office  Chemicals  shall comply at all
times  with all  Legal  Requirements,  including  Hazardous  Materials  Laws (as
defined below).  Upon Landlord's request from time to time, Tenant shall provide
to Landlord a complete written inventory of all Hazardous Materials which Tenant
anticipates  using or storing on, or discharging  from , the Premises along with
copies of all reports, permits and business plans filed with any federal, state,
local or other  governmental  agency.  Tenant  shall  update  the  inventory  as
frequently as required to reflect any material  changes to the items required to
be  disclosed  therein.  Tenant  shall  be  solely  responsible  for  and  shall
indemnify,  defend and hold Landlord and all other  Indemnitees   (as defined in
Section  13.a.  below),  harmless  from and  against  all Claims (as  defined in
Section  13.a.  below),  arising  out of or in  connection  with,  or  otherwise
relating  to (i) any  Handling of  Hazardous  Materials  by any Tenant  Party or
Tenant's breach of its obligations hereunder,  or (ii) any removal,  cleanup, or
restoration work and

                                       6
<PAGE>

materials  necessary  to  return  the Real  Property  or any other  property  of
whatever nature located on the Real Property to their  condition  existing prior
to the  Handling of   Hazardous  Materials   in, on or about the Premises by any
Tenant Party.  Tenant shall promptly provide Landlord with copies of all notices
received by it, including, without limitation, any notice of violations,  notice
of  responsibility  or  demand  for  action  from  any  federal,  state or local
authority or official in connection with the presence of Hazardous  Materials in
or about the Premises or any other portion of the Property.  In the event of any
release of Hazardous  Materials  upon the  Premises or any other  portion of the
Property, or upon adjacent lands, if caused by Tenant or any other Tenant Party,
Tenant shall promptly remedy the problem in accordance with all applicable Legal
Requirements.  For  purposes  of this  Lease,  "Hazardous  Materials"  means any
explosive,  radioactive  materials,  hazardous wastes, or hazardous  substances,
including without limitation  asbestos  containing  materials,  PCB's, CFC's, or
substances defined as "hazardous substances" in the Comprehensive  Environmental
Response,  Compensation and Liability Act of 1980, as amended, 42 U.S.C. Section
9601-9657; the Hazardous Materials Transportation Act of 1975, 49 U.S.C. Section
1801-1812; the Resource Conservation and Recovery Act of 1976, 42 U.S.C. Section
6901-6987;  or any other Legal Requirement  regulating,  relating to or imposing
liability or standards of conduct  concerning  any such  materials or substances
now or at any time  hereafter  in  effect  (collectively,  "Hazardous  Materials
Laws").   Tenant's  obligations  under  this  Section  8.d.  shall  survive  the
expiration or other termination of this Lease.

9. Alterations.

     a.  Alterations.   Tenant  shall  not  make  any  alteration,  addition  or
improvement in, to or upon the Premises ("Alteration") without the prior written
consent of Landlord in each  instance,  which consent shall not be  unreasonably
withheld with respect to proposed  Alterations  which (i) are not  structural in
nature,  (ii)  do not  affect  the  Base  Building  Components,  (iii)  are,  in
Landlord's  opinion,  compatible  with the  Building and the balance of the Real
Property    and    the    Building's    mechanical,     plumbing,    electrical,
heating/ventilation/air conditioning, communication, security and fire and other
life  safety  systems  (collectively,  the  "Building  Systems"),  and  (iv)  in
Landlord's  opinion will not  interfere  with the use and occupancy of any other
portion of the  Building or the Real  Property by any other  tenant or permitted
occupant thereof.  Tenant shall give Landlord not less than ten (10) days' prior
written notice of any Alteration  Tenant desires to make. Any  Alterations as to
which  Landlord  shall  consent  shall be made only by  contractors  approved in
advance,  in writing  by  Landlord,  which  approval  shall not be  unreasonably
withheld; provided, however, that Landlord may, in its sole discretion,  specify
the engineers and  contractors  to perform any work relating to or affecting the
Building Systems or the Base Building  Components.  Tenant shall comply with all
Legal Requirements applicable to each Alteration and shall deliver to Landlord a
complete set of "as built" plans and  specifications  for each  Alteration.  Any
work to the balance of the Building or Real  Property  related to or affected or
triggered  by  Tenant's  Alterations  shall be  performed  by Tenant at Tenant's
expense (or, at Landlord's election, Landlord may perform such work at  Tenant's
expense).  Tenant shall be solely  responsible for maintenance and repair of all
Alterations  made by Tenant.  Tenant shall pay Landlord on demand (whether prior
to or during the course of construction) an amount (the "Alteration  Fee") equal
to five percent (5%) of the total cost of each  Alteration  (and for purposes of
calculating  the  Alteration  Fee,  such cost shall  include  architectural  and
engineering fees, but shall not include permit fees) as compensation to Landlord
for miscellaneous  costs incurred by Landlord in connection with the Alteration.
In addition,  Tenant shall  reimburse  Landlord for all third party fees paid by
Landlord in connection with reviewing the proposed  Alterations  (whether or not
the proposed Alterations are ultimately approved by Landlord or made by Tenant),
including,  without limitation,  Landlord's  architectural and engineering fees.
All Alterations shall be performed diligently and  in a first-class  workmanlike
manner  and in accordance  with plans and  specifications  approved by Landlord,
and shall comply with Landlord's  construction  procedures and  requirements for
the  Building  (including  Landlord's  requirements  relating to  insurance  and
contractor qualifications and scheduling of the work).

     b. Liens.  If, because of any act or omission of Tenant or anyone  claiming
by, through, or under Tenant, any mechanic's lien or other lien is filed against
the Premises or any other portion of the Real

                                       7
<PAGE>

Property or against other property of Landlord (whether or not the lien is valid
or enforceable),  Tenant shall, at its own expense, cause it to be discharged of
record within a reasonable  time, not to exceed ten (10) days, after the date of
the filing. In addition,  Tenant shall defend and indemnify Landlord and hold it
harmless from any and all Claims resulting from the lien.  Without limitation of
Landlord's other remedies, Landlord shall have the rights under Section 16 below
if any such lien is not timely discharged by Tenant.

     c. Ownership of  Alterations.  All  Alterations  shall  immediately  become
Landlord's  property.  Except as provided in Section 9.d.,  Landlord may require
Tenant,  at  Tenant's  sole  expense  and by the end of the Term,  to remove any
Alterations  and  to  restore  the  Premises  to  its  condition  prior  to  the
Alteration.

     d. Request Regarding Removal  Obligation.  At the time that Tenant requests
Landlord's  consent to any  Alteration,  Tenant may request that Landlord notify
Tenant if Landlord will require Tenant, at Tenant's sole expense,  to remove any
or all of the  Alteration by the end of the Term, and to restore the Premises to
its condition  prior to the  Alteration.  Unless  Landlord  shall have expressly
agreed in writing  not to  require  such  removal  and  restoration,  Landlord's
election right under Section  9.c. shall continue through the end of the Term as
to such Alterations.

10. Repairs.

     a. Landlord's Repairs. Landlord shall maintain the roof, foundations, floor
slabs and  exterior  walls of the  Building  (collectively,  the "Base  Building
Components")  in good condition and repair,  reasonable  wear and tear excepted.
The term walls as used herein shall not include  windows,  glass or plate glass,
doors,  special  store  fronts or office  entries.  The term roof as used herein
shall not include  skylights,  smoke hatches or roof vents.  Landlord shall also
maintain in good condition and repair,  reasonable  wear and tear excepted,  the
Common Areas, including, but not limited to, the landscaped areas, parking areas
and driveways. Tenant shall reimburse Landlord for Landlord's costs of complying
with its  obligations  under this Section 10 in accordance with Section 5 above,
provided,  however, that any damage caused by or repairs necessitated by any act
of Tenant or any other  Tenant  Party may be repaired by Landlord at  Landlord's
option and at Tenant's expense. Tenant shall give Landlord prompt written notice
of any repairs  required of Landlord  pursuant to this  Section 10,  after which
notice Landlord shall have reasonable opportunity to perform the same.

     b. Tenant's Repairs. Tenant shall, at Tenant's expense,  maintain all parts
of the  Premises  in a good,  clean and secure  condition,  promptly  making all
necessary repairs and replacements  including,  but not limited to, all windows,
glass or plate  glass,  doors and any special  store  fronts or office  entries,
walls and wall finishes,  floor covering,  Building  Systems,  truck doors, dock
bumpers,  dock plates and  levelers,  plumbing  work and  fixtures,  downspouts,
skylights,  smoke hatches, roof vents and utility equipment, in each case to the
extent the same are located  within or  exclusively  serve the Premises.  Tenant
shall,  at Tenant's  expense,  also perform  necessary  pest  extermination  and
regular removal of trash and debris.  Landlord shall, at Tenant's expense, enter
into  a  regularly  scheduled  preventive  maintenance/service  contract  with a
maintenance contractor for servicing all hot water, heating and air conditioning
systems and equipment  within or serving the  Premises.  Tenant shall not damage
any demising wall or disturb the integrity and support  provided by any demising
wall and  shall,  at its sole  expense,  immediately  repair  any  damage to any
demising wall caused by Tenant or its employees, agents or invitees or any other
Tenant  Party.  Tenant hereby waives all right to make repairs at the expense of
Landlord or in lieu thereof to vacate the Premises and its other similar  rights
as provided in Califomia Civil Code Sections 1932(1), 1941 and 1942 or any other
Legal Requirement (whether now or hereafter in effect).

11. Damage or Destruction.

     a.  Landlord's  Obligation  to  Rebuild.  If the  Premises  are  damaged or
destroyed,  Landlord shall promptly and  diligently  repair the Premises  unless
Landlord has the option to terminate this Lease as

                                       8
<PAGE>

provided herein, and Landlord elects to terminate.

     b. Right to  Terminate.  Landlord  shall have the option to terminate  this
Lease if the  Premises or the  Building is destroyed or damaged by fire or other
casualty,  regardless  of whether  the  casualty is insured  against  under this
Lease, if Landlord  reasonably  estimates that the repair of the Premises or the
Building  cannot be  completed  within one hundred  eighty  (180) days after the
casualty.  Landlord  shall  also have the right to  terminate  this Lease if the
repair  is  not  fully  covered  by  insurance  maintained  (or  required  to be
maintained)  by the Landlord  pursuant to this Lease other than by reason of the
deductible amounts under Landlord's  insurance  policies.  Tenant shall have the
option to  terminate  this Lease if the Premises is damaged or destroyed by fire
or other  casualty,  and Landlord  reasonably  estimates  that the repair of the
Premises  cannot be completed  within one (1) year after the casualty.  Landlord
shall notify Tenant of Landlord's  reasonable repair period estimate within (60)
days after the  casualty.  If a party desires to exercise the right to terminate
this Lease as a result of a  casualty,  the party  shall  exercise  the right by
giving the other party written notice of its election to terminate within thirty
(30) days after delivery of Landlord's  repair period  estimate,  in which event
this Lease shall  terminate  fifteen (15) days after the date of the terminating
party's notice.  If neither Landlord nor Tenant exercises the right to terminate
this  Lease,  this Lease shall  continue  in full force and effect and  Landlord
shall  promptly  commence  the  process  of  obtaining   necessary  permits  and
approvals,  and shall commence repair of the Premises or the Building as soon as
practicable and thereafter prosecute the repair diligently to completion.

     c. Limited  Obligation to Repair.  Landlord's  obligation, should  Landlord
elect or be  obligated  to repair or rebuild,  shall be limited to the  Building
shell and any tenant improvements in the Premises which are constructed and paid
for by Landlord pursuant to Exhibit B. Tenant, at its option and expense,  shall
replace or fully repair all trade  fixtures,  equipment,  Alterations  and other
improvements  installed  by Tenant  and  existing  at the time of the  damage or
destruction.

     d.  Abatement  of Rent.  In the event of any damage or  destruction  to the
Premises which does not result in termination of this Lease, the Base Rent shall
be  temporarily   abated   proportionately   to  the  degree  the  Premises  are
untenantable as a result of the damage or destruction,  commencing from the date
of the damage or  destruction  and  continuing  during the  period  required  by
Landlord to  substantially  complete its repair and restoration of the Premises;
provided,  however,  that nothing  herein  shall  preclude  Landlord  from being
entitled to collect the full amount of any rent loss insurance proceeds.  Tenant
shall not be entitled to any  compensation  or damages from Landlord for loss of
the  use  of  the  Premises,   damage  to  Tenant's  Personal  Property  or  any
inconvenience  occasioned by any damage,  repair or  restoration.  Tenant hereby
waives  the  provisions  of  Section  1932,  Subdivision  2, and  Section  1933,
Subdivision 4, and Sections 1941 and 1942 of the California  Civil Code, and the
provisions  of any  similar  Legal  Requirement  (whether  now or  hereafter  in
effect).

     e. Insurance Proceeds.  If this Lease is terminated,  Landlord may keep all
the insurance  proceeds  resulting from the damage payable pursuant to insurance
coverage maintained by Landlord, and Tenant shall have no claims thereto.

12.  Eminent  Domain.  If all or any material part of the Premises or balance of
the Real  Property  is taken for public or  quasi-public  use by a  governmental
authority  under the power of eminent  domain or is conveyed  to a  governmental
authority in lieu of such taking (a "taking"), Landlord may terminate this Lease
by written notice to Tenant within thirty (30) days after the taking.  If all or
any  material  part of the  Premises  is taken,  and if the  taking  causes  the
remaining  part of the Premises to be  untenantable  and  inadequate  for use by
Tenant for the purpose for which they were leased,  then  Tenant,  at its option
and by giving  notice within  fifteen (15) days after the taking,  may terminate
this Lease as of the date  Tenant is  required to  surrender  possession  of the
Premises.  If part of the Premises is taken but the remaining part is tenantable
and adequate for Tenant's  use,  then this Lease shall be  terminated  as to the
part taken as of the date  Tenant is  required  to  surrender  possession,  and,
unless Landlord shall have terminated this Lease

                                       9
<PAGE>

pursuant  to  the  foregoing  provisions,  Landlord  shall  make  such  repairs,
alterations  and  improvements  as may be necessary to render the part not taken
tenantable,  and the Base Rent shall be reduced in proportion to the part of the
Premises taken. All compensation awarded for the taking shall be the property of
Landlord  without any deduction  therefrom for any estate of Tenant,  and Tenant
hereby  assigns to  Landlord  all its right,  title and  interest  in and to the
award.  Tenant shall have the right,  however,  to recover from the governmental
authority,  but not from Landlord, such compensation as may be awarded to Tenant
on account of the  interruption  of  Tenant's  business,  moving and  relocation
expenses and removal of Tenant's Personal Property, provided that any such award
to Tenant will not reduce the award which would otherwise be made to Landlord.

13. Indemnity and Insurance.

     a. Indemnity. Tenant shall hold Landlord and its constituent  shareholders,
partners,  members  or  other  owners,  and all of  their  agents,  contractors,
servants,  officers,  directors,  employees  and  licensees  (collectively  with
Landlord,  the  "Indemnitees")   harmless  from and  indemnify  the  Indemnitees
against any and all claims, liabilities,  damages, costs and expenses, including
reasonable  attorneys'  fees and costs  incurred in  defending  against the same
(collectively,  "Claims"),  to the extent arising from (a) the acts or omissions
of Tenant or any other  Tenant Party in, on or about the Real  Property,  or (b)
any  construction  or other work  undertaken by or on behalf of Tenant in, on or
about the  Premises,  whether  prior to or during the Term, or (c) any accident,
injury or damage, howsoever and by whomsoever caused, to any person or property,
occurring  in, on or about the  Premises;  except to the extent  such Claims are
caused by the  negligence or willful  misconduct  of Landlord or its  authorized
representatives.  In case any action or proceeding be brought against any of the
Indemnitees  by reason of any such Claim,  Tenant,  upon  notice from  Landlord,
covenants  to  resist  and  defend  at  Tenant's  sole  expense  such  action or
proceeding by counsel  reasonably  satisfactory  to Landlord.  The provisions of
this Section 13.a.  shall survive the expiration or earlier  termination of this
Lease with respect to any injury,  illness,  death or damage  occurring prior to
such expiration or termination.

     b. Fire and Extended Coverage.  Landlord shall procure and maintain in full
force and effect with respect to the Building (including any tenant improvements
in the Premises  constructed  and paid for by Landlord  pursuant to Exhibit B) a
policy or policies of all risk  insurance  (including  sprinkler,  vandalism and
malicious mischief coverage,  and any other endorsements desired by the Landlord
or required by the holder of any fee or leasehold mortgage on the Real Property,
but excluding,  at Landlord's option,  the insurance  described in Section 13.i.
below) in such amount as  Landlord  shall  determine,  but in an amount at least
equal to eighty  percent (80%) (or such greater  percentage as shall be required
to preclude  Landlord  from being deemed a coinsurer)) of  the full  replacement
cost (including debris removal,  and demolition,  but excluding the land and the
footings,  foundations and installations below the basement level) thereof. Such
insurance,  and all other  insurance  maintained  by Landlord  under this Lease,
shall be for the sole benefit of Landlord,  and the proceeds  therefrom shall be
under Landlord's sole control.

     c. Public Liability.  Tenant,  at its own cost and expense,  shall keep and
maintain  in full  force and  effect  during  the Term the  following  insurance
coverages,  written by an  insurance  company  licensed by and admitted to issue
insurance in the State of California,  with a general  policyholders'  rating of
"A" or better and a financial  size ranking of "Class X" or higher,  in the most
recent edition of Best's Insurance Guide, in the form customary to the locality,
(i) commercial  general liability  insurance,  including  contractual  liability
coverage,  insuring Tenant's  activities with respect to the Premises and/or the
Building  against loss,  damage or liability for personal injury or death of any
person or loss or damage to property  occurring  in, upon or about the Premises,
with a minimum coverage of One Million Dollars  ($1,000,000) per  occurrence/Two
Million  Dollars  ($2,000,000)  general  aggregate,  plus a Five Million  Dollar
($5,000,000) per occurrence/general  aggregate umbrella,  (ii) fire damage legal
liability insurance and  personal/advertising  injury insurance (which shall not
be subject to the contractual liability  exclusion),  each in the minimum amount
of One Million Dollars  ($1,000,000),  (iii) medical  payments  insurance in the
minimum amount of

                                       10
<PAGE>

Five  Thousand  Dollars  ($5,000),   (iv)  worker's  compensation  insurance  in
statutory  amounts,  and (v) if  Tenant  operates  owned,  leased  or  non-owned
vehicles on the Property,  comprehensive  automobile  liability insurance with a
minimum coverage of $1,000,000 per occurrence, Two Million Dollars  ($2,000,000)
general  aggregate;  provided,  however,  that if, at any time  during the Term,
Tenant shall have in full force and effect a blanket policy of public  liability
insurance with the same coverage for the Premises as described above, as well as
coverage of other premises and properties of Tenant, or in which Tenant has some
interest,  the blanket  insurance  shall satisfy the  requirement  hereof and be
endorsed to separately apply to the Premises.

     d. Rental Abatement Insurance. Landlord may keep and maintain in full force
and effect during the Term rental abatement  insurance against abatement or loss
of rents with  respect to the Real  Property  in such  amount as  determined  by
Landlord.

     e. Insurance  Certificates.  Tenant shall furnish to Landlord, on or before
the  Commencement  Date and  thereafter  within  thirty  (30) days  prior to the
expiration of each policy,  an original  certificate of insurance  issued by the
insurance carrier of each policy of insurance carried by Tenant pursuant to this
Section 13. The certificates shall expressly provide that the policies shall not
be  cancelable  or subject to  reduction  of coverage or otherwise be subject to
modification  except after thirty (30) days' prior written notice to the parties
named as insureds.  Landlord,  its  successors  and assigns,  and any nominee of
Landlord holding any interest in the Premises,  including,  without  limitation,
any ground lessor or the holder of any fee or leasehold mortgage, shall be named
as an  additional  insured  under each policy of insurance  maintained by Tenant
pursuant to this Lease. The policies and certificates shall further provide that
the coverage shall be primary,  and that any coverage  carried by Landlord shall
be secondary and noncontributory with respect to Tenant's policy.

     f. Tenant's Failure.  If Tenant fails to maintain any insurance required by
this  Lease,  Tenant  shall be liable  for any loss or cost  resulting  from the
failure.  This Section  shall not be deemed to be a waiver of any of  Landlord's
rights and remedies under any other provision of this Lease.

     g. Waiver of Subrogation. Any policy or policies of fire, extended coverage
or similar casualty  insurance which either party obtains in connection with the
Building,  the Premises, or Tenant's Personal Property shall include a clause or
endorsement  denying  the insurer  any rights of  subrogation  against the other
party (and the other parties named as additional insureds  pursuant  to  Section
13.e.  above) to the extent  rights have been waived by the insured prior to the
occurrence  of injury or loss.  Landlord  and Tenant  each  waives any rights of
recovery  against the other (and the other parties named as additional  insureds
pursuant to Section 13.e. above)  for injury or loss due to hazards insurable by
policies of fire, extended coverage or similar casualty insurance, regardless of
whether such insurance policies or coverage shall actually have been obtained by
the party  granting  such waiver,  and  regardless  of the cause of such fire or
casualty,  including the  negligence of the party  benefiting  from such waiver.
Because this Section 13.g will preclude the assigmnent of any claim mentioned in
it by way of  subrogation  or  otherwise  to an  insurance  company or any other
person,  each  party to this  Lease  agrees  immediately  to give to each of its
insurance  companies written notice of the terms of the mutual waivers contained
in this Section 13.g and to have the insurance policies properly   endorsed,  if
necessary,  to prevent the invalidation of the insurance  coverages by reason of
the mutual waivers contained in this Section 13.g.

     h. Tenant's  Property and Fixtures.  Tenant shall assume the risk of damage
to any of Tenant's furniture,  equipment, machinery, goods, supplies or fixtures
or other Personal Property,  and to any Alterations which Tenant may make to the
Premises,  and  shall  insure  the same  throughout  the Term,  for  their  full
replacement cost, under insurance policies  reasonably  satisfactory to Landlord
(certificates  of which  shall be  delivered  to  Landlord as set forth above in
Section 13.e). Tenant hereby releases Landlord from any obligation to insure the
foregoing  items and from any  liability  for loss of or  damage to such  items,
regardless of cause.

                                       11
<PAGE>

     i.  Earthquake  and Flood  Insurance.  In addition  to any other  insurance
policies carried by Landlord in connection with the Building, Landlord may elect
to procure and maintain in full force and effect during the Term with respect to
the Building a policy of  earthquake/volcanic  action and flood  and/or  surface
water insurance,  including rental value insurance  against abatement or loss of
rent in the case of damage or loss  covered  under the  earthquake/volcanic  and
flood and/or  surface water  insurance,  in an amount up to one hundred  percent
(100%) of the full replacement cost (including debris removal and demolition) of
the Building.

14. Assignment or Sublet.

     a. Tenant shall not assign this Lease or sublet the Premises or any portion
thereof  without the prior written  consent of Landlord in each instance,  which
consent  shall not,  subject to  Landlord's  rights under  clause (i) below,  be
unreasonably  withheld.  If Tenant desires to assign this Lease or to sublet the
Premises,  or any part thereof,  Tenant shall give to Landlord written notice of
its  intent at least  sixty  (60) days in  advance  of the date on which  Tenant
desires to assign or sublet the Premises, which notice shall designate the terms
of the proposed  assignment or sublet,  the identity of the proposed assignee or
sublessee,  and shall be  accompanied  by financial  statements of such proposed
assignee or sublessee and such other  information  regarding  such party and its
business  and  reputation  as shall be required  by  Landlord  to  evaluate  the
proposed  assignment  or  sublet.  Landlord  shall have  thirty  (30) days after
receipt of Tenant's  written notice and the above specified  information  within
which to notify  Tenant in writing that Landlord  elects to (i)  terminate  this
Lease,  in the case of a proposed  assignment,  or to terminate this Lease as to
that  portion of the  Premises to be sublet,  in the case of a proposed  sublet,
(ii)  consent to the  proposed  assignment  or sublet as  described  in Tenant's
notice, or (iii) reasonably refuse to consent to Tenant's proposed assignment or
sublet, stating the reasons for such refusal. If Landlord fails to notify Tenant
in writing of its election within the thirty (30) day period,  Landlord shall be
deemed to have made the election in clause  (iii) above.  No consent by Landlord
to any  assignment  or  sublet  shall be  deemed  to be a  consent  to a use not
permitted  under this  Lease,  to any act in  violation  of this Lease or to any
subsequent assignment or sublet. No assignment or sublet by Tenant shall relieve
Tenant of any liability  theretofore or thereafter arising under this Lease. Any
attempted assignment or sublet by Tenant in violation of the terms and covenants
of this Section shall be void.

     During the first six (6) months of the Term, the sixty (60) and thirty (30)
day periods in the preceding paragraph shall each be reduced to ten (10) days.

     Notwithstanding the provisions of the foregoing  paragraph,  Landlord shall
not have  the  termination  option  described  in  clause  (i) of the  preceding
paragraph as to any sublease  proposed by Tenant which will terminate  three (3)
years or earlier from the  Commencement  Date,  unless the space subject to such
sublease,  taken together with all other portions of the Premises subject to any
sublease,  would exceed fifty percent  (50%) of the total  Premises then demised
under this Lease. In addition,  Landlord shall not have the  termination  option
described in clause (i) of the preceding  paragraph as to any sublease  proposed
by Tenant  if,  within  ten (10) days  after  Tenant's  receipt  of notice  from
Landlord that Landlord is exercising such  termination  right,  Tenant withdraws
its request for Landlord's consent to such sublease.

     If Tenant shall  propose to assign this Lease  effective as of a date which
is during  the first two (2) years of the Term,  or if Tenant  shall  propose to
sublease any portion of the Premises  effective as of a date which is during the
first two (2) years of the Term and the term of such  sublease  is for more than
three (3) years,  due to the  potential  material  adverse  affect such proposed
transaction  would have on  Landlord's  ability to lease the balance of the Real
Property,  Landlord's refusal to consent to any such proposed  transaction shall
be  deemed  reasonable  (without  limitation  of any  other  reasonable  grounds
Landlord may have for refusing to consent to any assignment or subletting).

     b. Processing Expenses. Tenant shall pay to Landlord, as Landlord's cost of
processing each

                                       12
<PAGE>

proposed  assignment  or  subletting  (whether  or not the  same  is  ultimately
approved by Landlord or  consummated  by Tenant),  an amount equal to the sum of
(i) Landlord's  reasonable attorneys' and other professional fees, plus (ii) the
sum of  $1000.00  for the  cost of  Landlord's  administrative,  accounting  and
clerical time (collectively,  "Processing Costs").  Notwithstanding  anything to
the contrary  herein,  Landlord shall not be required to process any request for
Landlord's  consent to an  assignment  or  subletting  until  Tenant has paid to
Landlord the amount of Landlord's  estimate of the  Processing  Costs.  When the
actual amount of the Processing Costs is determined, it shall be reconciled with
Landlord's  estimate,  and any payments or refunds  required as a result thereof
shall promptly thereafter be made by the parties.

     c.  Consideration to Landlord.  In the event of any assignment or sublease,
whether or not  requiring  Landlord's  consent,  Landlord  shall be  entitled to
receive,  as  additional  rent  hereunder,  seventy-five  percent  (75%)  of any
consideration (including, without limitation, payment for leasehold improvements
and any  "Leasehold  Profit" as defined below) paid by the assignee or subtenant
for the assignment or sublease and, in the case of a sublease, the excess of the
amount of rent paid for the  sublet  space by the  subtenant  over the amount of
Monthly Base Rent under Section 4 above and Operating  Expenses  under Section 5
above attributable to the sublet space for the corresponding  month; except that
Tenant may  recapture,  on an  amortized  basis over the term of the sublease or
assignment,  any brokerage  commissions  paid by Tenant in  connection  with the
subletting or assignment (not to exceed commissions typically paid in the market
at the time of such  subletting or  assignment),  Tenant's  reasonable  costs of
advertising the space for sublease or assignment, any improvement allowance paid
by Tenant to the subtenant or assignee, and any improvement costs paid by Tenant
solely to prepare the space for the  assignment or sublet..  "Leasehold  Profit"
shall be the  value  allocated  to the  leasehold  between  the  parties  to the
assignment  or  sublease,  but in no event less than the  excess of the  present
value of the fair market rent of the  Premises  for the  remaining  term of this
Lease after such  assignment or sublease,  over the Base Rent payable  hereunder
for such remaining  term, as reasonably  determined by Landlord.  Upon Landlords
request,  Tenant shall  direct any  subtenant or assignee to pay the directly to
Landlord  the amounts  due to it  pursuant to this  Section 14.c. on  account of
such  sublease  or  assignment.  If there is more than one  sublease  under this
Lease,  the amounts  (if any) to be paid by Tenant to Landlord  pursuant to this
Section 14.c.  shall be separately  calculated for each sublease and amounts due
Landlord  with regard to any one sublease may not be offset  against  rental and
other consideration pertaining to or due under any other sublease.

     d. Documentation.  No permitted assignment or subletting by Tenant shall be
effective   until  there  has  been  delivered  to  Landlord  a  fully  executed
counterpart of the assignment or sublease which  expressly  provides that (i) in
the case of a sublease,  the  subtenant  may not assign its  sublease or further
sublet the sublet space without  Landlord's prior written  consent,  (ii) in the
case of an assignment,  the assignee assumes all of Tenant's  obligations  under
this Lease arising on or after the date of the assignment, and (iii) in the case
of a sublease,  the  subtenant  agrees to be and remain  jointly  and  severally
liable with Tenant to Landlord for the payment of Rent  pertaining to the sublet
space in the amount set forth in the sublease, and for the performance of all of
the terms and  provisions  of this  Lease  pertaining  to the sublet  space.  In
addition  to the  foregoing,  no  assignment  or  sublease  by  Tenant  shall be
effective   until  there  has  been  delivered  to  Landlord  a  fully  executed
counterpart of Landlord's consent to assignment or sublease form, as applicable.
The  failure  or  refusal  of a  subtenant  or  assignee  to  execute  any  such
instrument   shall not release or  discharge  the subtenant or assignee from its
liability as set forth above.  Notwithstanding  the  foregoing,  no subtenant or
assignee  shall be  permitted  to occupy  the  Premises  unless  and until  such
subtenant or assignee provides  Landlord with certificates  evidencing that such
subtenant or assignee is carrying all  insurance  coverage  required of it under
this Lease.

     e. No Merger.  Without  limiting any of the  provisions of this Section 14,
the  voluntary  or  other  surrender  of  this  Lease  by  Tenant,  or a  mutual
cancellation by Landlord and Tenant,  shall not work a merger, and shall, at the
option of Landlord,  terminate all or any existing subleases or subtenancies or,
at the option of Landlord,  operate as an  assignment  to Landlord of any or all
such subleases or   subtenancies.  If Landlord does elect that such surrender or
cancellation operate as an assignment of such subleases or subtenancies,

                                       13
<PAGE>

Landlord  shall in no way be liable for any  previous  act or omission by Tenant
under the subleases or for the return of any deposit(s) under the subleases that
have not been actually delivered to Landlord, nor shall Landlord be bound by any
sublease  modification(s) executed without Landlord's consent or for any advance
rental payment by the subtenant in excess of one month's rent.

     f.  Indirect  Assignments.  For purposes of this Section 14, the  following
events  shall be deemed an  assignment  or  sublease,  as  appropriate:  (i) the
issuance of equity interests (whether stock, partnership interests or otherwise)
in Tenant or any subtenant or assignee,  or any entity  controlling any of them,
to any person or group of related persons,  in a single  transaction or a series
of related or unrelated  transactions,  such that, following such issuance, such
person or group shall have Control (as defined below) of Tenant or any subtenant
or assignee;  (ii) a transfer of Control of Tenant or any subtenant or assignee,
or any entity  controlling  any of them, in a single  transaction or a series of
related  or  unrelated   transactions   (including,   without   limitation,   by
consolidation, merger, acquisition or reorganization),  except that the transfer
of  outstanding  capital  stock or other listed  equity  interests by persons or
parties other than "insiders" within the meaning of the Securities  Exchange Act
of 1934, as amended,  through the  "over-the-counter"  market or any  recognized
national  or  intemational  securities  exchange,   shall  not  be  included  in
determining whether Control has been transferred;  (iii) a reduction of Tenant's
assets to the point  that this  Lease  and/or  other  leases  are  substantially
Tenant's only asset(s);  or (iv) a change or conversion in the form of entity of
Tenant, any subtenant or assignee,  or any entity controlling any of them, which
has the effect of limiting  the  liability  of any of the  partners,  members or
other owners of such entity.  "Control" shall mean direct or indirect  ownership
of 50% or more of all of the voting stock of a corporation or 50% or more of the
voting legal or equitable interest in any other business entity, or the power to
direct the  management  and  operations  of any  entity  (by  equity  ownership,
contract or otherwise).

     g.  Affiliates;  Successors.  Notwithstanding  anything to the  contrary in
Section  14.a or Section  14.c.,  but  subject to the other  provisions  of this
Section 14,  Tenant may assign this Lease or sublet the  Premises or any portion
thereof,  without Landlord's consent,  to any partnership,  corporation or other
entity which controls,  is controlled by, or is under common control with Tenant
(control  being  defined for such purposes as ownership of 50% or more of all of
the  voting  stock  of a  corporation  or 50% or more  of the  voting  legal  or
equitable  interest in any other  business  entity,  and the power to direct the
management and operations of, the relevant  entity) (an  "Affiliate")  or to any
partnership,   corporation   or  other  entity   resulting   from  a  merger  or
consolidation with Tenant or which acquires all or substantially all of Tenant's
assets  (through a transfer of assets or equity  interests in Tenant) as a going
concern  and such assets  include  substantial  assets  other than this Lease (a
"Successor"),  provided that (i) Landlord receives at least ten (10) days' prior
written notice of the assignment or subletting,  in which Tenant shall expressly
confirm that Tenant remains  primarily liable (together with the assignee in the
event of an  assignment)  for all of the  obligations  of the Tenant  under this
Lease,  (ii) in the case of an assignment to a Successor,  the  Successor's  net
worth is not less than Tenant's net worth  immediately  prior to such assignment
(or series of  transactions  of which such  assignment is a part),  (iii) in the
case of a subletting or assignment  to an  Affiliate,  the Affiliate  remains an
Affiliate  for the duration of the  subletting or the balance of the term in the
event of an  assignment,  (iv)  Landlord  receives a fully  executed copy of the
assignment or sublease  agreement  between Tenant and the Affiliate or Successor
at least  ten  (10)  days  prior to the  effective  date of such  assignment  or
sublease,  in which the Affiliate or Successor,  as the case may be, assumes (in
the event of an assignment) all of Tenant's  obligations  under this Lease,  and
agrees (in the event of a sublease)  that such  subtenant  will,  at  Landlord's
election, attorn directly to Landlord in the event that this Lease is terminated
for any reason,  and (v) in the case of an assignment,  the essential purpose of
such  assignment is to transfer an active,  ongoing  business  with  substantial
assets in addition to this Lease,  and in the case of an  assignment or sublease
the transaction is for legitimate  business purposes unrelated to this lease and
the transaction is not a subterfuge by Tenant to avoid it obligations under this
Lease or the restrictions on assignment and subletting contained herein.

                                       14
<PAGE>

15. Default.

     a. Tenant's Default.  A material breach of this Lease by Tenant shall exist
if any of the following  events  (severally,  "Event of Default";  collectively,
"Events of Default")  shall  occur:  (i) if Tenant shall have failed to pay Base
Rent, Tenant's  Percentage Share of increased  Operating Expenses,  or any other
sum required to be paid  hereunder  when due,  including  any interest due under
Section 3; (ii) if Tenant  shall have  failed to perform  any term,  covenant or
condition of this Lease except those requiring the payment of money,  and Tenant
shall have  failed to cure the breach  within  fifteen  (15) days after  written
notice from Landlord if the breach could  reasonably be cured within the fifteen
(15) day period; provided, however, if the failure could not reasonably be cured
within the fifteen (15) day period,  then Tenant shall not be in default  unless
it has failed to promptly commence and thereafter  continue to make diligent and
reasonable  efforts to cure the  failure as soon as  practicable  as  reasonably
determined  by Landlord;  (iii) if Tenant shall have assigned its assets for the
benefit  of its  creditors;  (iv) if the  sequestration  of,  attachment  of, or
execution  on, any  material  part of the  property of Tenant or on any property
essential to the conduct of Tenant's  business shall have occurred,   and Tenant
shall have failed to obtain a return or release of the  property  within  thirty
(30) days thereafter, or prior to sale pursuant to any sequestration, attachment
or levy,  whichever is earlier;  (v) if Tenant shall have failed to continuously
and  uninterruptedly  conduct  its  business  in the  Premises,  or  shall  have
abandoned  or vacated the  Premises;  (vi) if a court shall have made or entered
any decree or order adjudging  Tenant to be insolvent,  or approving as properly
filed a petition seeking  reorganization  of Tenant, or directing the winding up
or  liquidation  of Tenant,  and the decree or order shall have  continued for a
period of thirty (30) days;  (vii) if Tenant  shall make or suffer any  transfer
which  constitutes  a  fraudulent  or  otherwise  avoidable  transfer  under any
provision of the federal  Bankruptcy Laws or any applicable state law; or (viii)
if Tenant shall have failed to comply with the  provisions  of Sections 23 or 25
of this Lease within the time periods stated therein.  An Event of Default shall
constitute a default under this Lease.

     b. Remedies Upon Tenant's Default. Upon an Event of Default, Landlord shall
have the  following  remedies,  in  addition  to all other  rights and  remedies
provided by law, equity,  statute or otherwise  provided in this Lease, to which
Landlord may resort cumulatively or in the alternative:

         (i) Landlord has the remedy  described in California Civil Code Section
1951.4 (a landlord may  continue  the lease in effect after the tenant's  breach
and  abandonment and recover rent as it becomes due, if the tenant has the right
to sublet and assign subject only to reasonable  limitations),  and may continue
this Lease in full force and effect, and this Lease shall continue in full force
and effect as long as Landlord does not terminate  Tenant's right to possession,
and Landlord  shall have the right to collect  Rent when due.  During the period
Tenant is in default,  Landlord may enter the Premises and relet it, or any part
of it, to third parties for Tenant's  account,  provided that any Rent in excess
of the Rent due hereunder  shall be payable to Landlord.  Tenant shall be liable
immediately to Landlord for all costs Landlord incurs in reletting the Premises,
including,  without limitation,  brokers' commissions,  expenses of cleaning and
redecorating  the Premises  required by the reletting and like costs.  Reletting
may be for a period  shorter or longer  than the  remaining  Term of this Lease.
Tenant shall pay to Landlord the Rent and other sums due under this Lease on the
dates the Rent is due, less the Rent and other sums  Landlord  receives from any
reletting.  No act by Landlord  allowed by this  Subsection (i) shall  terminate
this Lease unless  Landlord  notifies  Tenant in writing that Landlord elects to
terminate this Lease.

         (ii)  Landlord  may  terminate  Tenant's  right  to  possession  of the
Premises at any time by giving written notice to that effect. No act by Landlord
other than giving written notice to Tenant of such  termination  shall terminate
this  Lease.  Acts  of  maintenance,  efforts  to  relet  the  Premises  or  the
appointment  of a  receiver  on  Landlord's  initiative  to  protect  Landlord's
interest  under this Lease shall not  constitute a termination of Tenant's right
to  possession.  On  termination,  Landlord  shall  have the right to remove all
personal  property of Tenant and store it at Tenant's  cost and to recover  from
Tenant as  damages:  (a) the worth at the time of award of unpaid Rent and other
sums due and payable which had been earned at the

                                       15
<PAGE>

time of  termination;  plus (b) the worth at the time of award of the  amount by
which the  unpaid  Rent and other  sums due and  payable  which  would have been
payable after termination until the time of award exceeds the amount of the Rent
loss that Tenant proves could have been reasonably  avoided;  plus (c) the worth
at the time of award of the amount by which the  unpaid  Rent and other sums due
and  payable for the  balance of the Term after the time of award  exceeds   the
amount of the Rent loss that Tenant proves could be reasonably avoided; plus (d)
any  other  amount  necessary  to  compensate  Landlord  for all  the  detriment
proximately  caused by Tenant's  failure to perform Tenant's  obligations  under
this  Lease,  or which,  in the  ordinary  course of things,  would be likely to
result therefrom,  including, without limitation, any costs or expenses incurred
by Landlord:  (1) in retaking possession of the Premises,  including  reasonable
attorneys' fees and costs  therefor;  (2) maintaining or preserving the Premises
for reletting to a new tenant,  including repairs or alterations to the Premises
for the reletting;  (3) leasing  commissions;   (4) any other costs necessary or
appropriate to relet the Premises;  and (5) at Landlord's  election!  such other
amounts in addition to or in lieu of the foregoing as may be permitted from time
to time by California  Civil Code Section  1951.2 or any other laws of the State
of California.

The  "worth at the time of  award" of the  amounts  referred  to in  Subsections
(ii)(a) and  (ii)(b) is computed by allowing  interest at the lesser of eighteen
percent (18%) per annum or the maximum rate permitted by law, on the unpaid Rent
and other sums due and payable from the date due through the date of award.  The
"worth at the time of award" of the amount referred to in Subsection  (ii)(c) is
computed by discounting  the amount at the discount rate of the Federal  Reserve
Bank of San Francisco at the time of award, plus one percent (1%). Tenant waives
redemption or relief from  forfeiture  under  California Code of Civil Procedure
Sections  1174 and 1179,  or under any other present or future law, if Tenant is
evicted or Landlord takes possession of the Premises by reason of any default of
Tenant hereunder.

     c. Landlord's Default. Landlord shall not be deemed to be in default in the
performance  of any  obligation  required to be performed by Landlord  hereunder
unless and until  Landlord has failed to perform the  obligation  within  thirty
(30) days after receipt of written  notice by Tenant to Landlord  specifying the
obligation Landlord has failed to perform; provided, however, that if the nature
of  Landlord's  obligation  is such that more than thirty (30) days are required
for its  performance,  then  Landlord  shall not be deemed to be in  default  if
Landlord shall commence the  performance  of such  obligation  within the thirty
(30)  day  period  and  thereafter  shall  diligently   prosecute  the  same  to
completion.

16. Landlord's Right to Perform Tenant's Covenants.

     If Tenant  shall at any time fail to make any  payment or perform any other
act on its part to be made or  performed  under this Lease,  Landlord  may,  but
shall not be  obligated  to,  make the  payment or perform  any other act to the
extent  Landlord may deem desirable and, in connection  therewith,  pay expenses
and employ  counsel.  Any payment or  performance by Landlord shall not waive or
release Tenant from any obligations of Tenant under this Lease. All sums so paid
by Landlord,  and all  penalties,  interest and costs in  connection  therewith,
shall be due and  payable  by  Tenant  on the  next day  after  any  payment  by
Landlord, together with interest thereon at the Interest Rate, from that date to
the date of payment  thereof by Tenant to Landlord,  plus  collection  costs and
attorneys'  fees.  Landlord  shall  have the same  rights and  remedies  for the
nonpayment thereof as in the case of default in the payment of Base Rent.

17. Security Deposit;: Letter of Credit.

     a.  Security  Deposit.  Tenant has  deposited  with  Landlord  the Security
Deposit, in the amount specified in the Basic Lease Information, as security for
the  full  and  faithful  performance  of every  provision  of this  Lease to be
performed by Tenant.  If Tenant  defaults  with respect to any provision of this
Lease, Landlord may use, apply or retain all or any part of the Security Deposit
for the  payment  of any Rent or other sum in  default,  for the  payment of any
amount   which  Landlord  may expend or become  obligated to expend by reason of
Tenant's default,  or for any loss or damage which Landlord may suffer by reason
of

                                       16
<PAGE>

Tenant's  default;  provided,  however,  that the Security  Deposit shall not be
deemed an advance rent deposit or an advance  payment of any kind,  or a measure
or limitation of Landlord's damages or constitute a bar or defense to any of the
Landlord's other remedies under this Lease or at law upon Tenant's  default.  If
any portion of the Security  Deposit is used or applied,  Tenant  shall  deposit
with Landlord,  within ten (10) days after written demand  therefor,  cash in an
amount  sufficient  to restore  the  Security  Deposit to its  original  amount.
Landlord  shall not be required to keep the Security  Deposit  separate from its
general  funds,  and Tenant  shall not be entitled  to interest on the  Security
Deposit.  Upon the expiration or earlier termination of this Lease, and Tenant's
fulfillment of all of its obligations hereunder (including any obligations which
survive  such  expiration  or earlier  termination),  Landlord  shall return the
Security  Deposit (or the balance  thereof  after  application  as aforesaid) to
Tenant.

     b. Letter of Credit.  In addition to the  Security  Deposit  made by Tenant
pursuant to Section 17.a.,  concurrently with Tenant's execution and delivery of
this Lease to  Landlord,  Tenant has  delivered to Landlord the Letter of Credit
described  below  as  security  for  Tenant's  performance  of all  of  Tenant's
covenants and obligations under this Lease; provided,  however, that neither the
Letter of Credit nor any proceeds  therefrom  (the "Letter of Credit  Proceeds")
shall be deemed an advance rent deposit or an advance payment of any other kind,
or a measure or limitation of Landlord's  damages or constitute a bar or defense
to any of the Landlord's other remedies under this Lease or at law upon Tenant's
default.  The Letter of Credit  shall be  maintained  in effect from the date of
this Lease through ninety (90) days after the expiration or earlier  termination
of the Term,  and on or prior to the  expiration of such ninety (90) day period,
Landlord  shall  return to Tenant the  Letter of Credit  (unless  presented  for
payment  as  provided  herein)  and any Letter of Credit  Proceeds  then held by
Landlord  (other than those held for  application by Landlord as provided below,
including  application  to cure any failure by Tenant to restore the Premises as
required by this Lease upon the surrender thereof);  provided,  however, that in
no event shall any such return be construed  as an  admission  by Landlord  that
Tenant has performed all of its  obligations  hereunder.  Landlord  shall not be
required to segregate the Letter of Credit  Proceeds from its other funds and no
interest shall accrue or be payable to Tenant with respect thereto. Landlord may
(but shall not be required to) draw upon the Letter of Credit and use the Letter
of Credit Proceeds or any portion thereof to cure any Event of Default by Tenant
under this Lease or to compensate  Landlord for any damage  Landlord incurs as a
result of Tenant's failure to perform any of its obligations hereunder, it being
understood  that any use of the Letter of Credit Proceeds shall not constitute a
bar or defense to any of Landlord's  other  remedies  under this Lease.  In such
event and upon written  notice from Landlord to Tenant  specifying the amount of
the Letter of Credit Proceeds so utilized by Landlord and the particular purpose
for which such amount was applied,  Tenant shall immediately deliver to Landlord
an amendment to the Letter of Credit or a replacement thereof in an amount equal
to one hundred  percent (100%) of the amount  specified below for the applicable
period.  Tenant's  failure to deliver such  amendment or replacement to Landlord
within five (5) days of Landlord's  notice shall  constitute an Event of Default
hereunder.  No lessor  under  any  ground  or  underlying  lease or holder of or
beneficiary under a mortgage or deed of trust, nor any purchaser at any judicial
or private  foreclosure  sale of the Property or any portion  thereof,  shall be
responsible to Tenant for such Letter of Credit or any Letter of Credit Proceeds
unless such lessor, holder or purchaser shall have actually received the same.

     c.  As  used  herein,   Letter  of  Credit  shall  mean  an  unconditional,
irrevocable letter of credit (hereinafter referred to as the "Letter of Credit")
issued at Tenant's  sole  expense by the San  Francisco  or New York office of a
major national bank satisfactory  to Landlord (the "Bank"),  naming  Landlord as
beneficiary,  and in form and substance  satisfactory to Landlord, in the amount
of One Million Dollars ($1,000,000.00) (subject to increase by the amount of the
Improvement  Advance as described below) for the during the period from the date
of this Lease through the first annual anniversary of the Commencement Date, and
reducing in amount on the first annual  anniversary of the Commencement Date and
on each subsequent annual anniversary of the Commencement Date by twenty percent
(20%) of the original amount of the Letter of Credit; provided, however, that if
on the date the Letter of Credit  amount  would  otherwise  reduce,  an Event of
Default, or default that with notice or the passage of time or both could mature
into an Event of Default,  shall have occurred and be continuing,  the Letter of
Credit amount shall not reduce on such date and shall not thereafter

                                       17
<PAGE>

reduce  until the later of the next  scheduled  reduction  date or the date such
Event of Default or default shall have been cured. The Letter of Credit shall be
for a one-year or, at Tenant's  election,  longer,  term and shall provide:  (i)
that  Landlord may make partial and multiple  draws  thereunder,  up to the face
amount thereof,  (ii) that Landlord may draw upon the Letter of Credit up to the
full  amount  thereof,  as  determined  by  Landlord,  and the Bank  will pay to
Landlord  the  amount  of such draw upon  receipt  by the Bank of a sight  draft
signed by Landlord and accompanied by a written  certification  from Landlord to
the Bank  stating  either:  (a) that an Event of  Default  has  occurred  and is
continuing  under this Lease,  or (b) that Landlord has not received notice from
the Bank that the Letter of Credit  will be renewed by the Bank for at least one
(1), year beyond the then relevant expiration  date and Tenant has not furnished
Landlord with a replacement  Letter of Credit as  hereinafter  provided,  or (c)
that Bank no longer  meets the  requirements  set forth above and Tenant has not
furnished  Landlord  with a replacement  Letter of Credit as required  hereunder
from a Bank  meeting  such  requirements;  and  (iii)  that,  in  the  event  of
Landlord's  assignment  or other  transfer of its interest in this   Lease,  the
Letter of Credit shall be freely  transferable  by Landlord,  without charge and
without  recourse,  to the assignee or  transferee of such interest and the Bank
shall confirm the same to Landlord and such assignee or  transferee.  The Letter
of Credit shall further  provide that a draw thereon  pursuant to clause (ii)(b)
above may only be made  during the thirty  (30) day  period  preceding  the then
applicable  expiration date of the Letter of Credit.  In the event that the Bank
shall fail to notify  Landlord  that the Letter of Credit will be renewed for at
least one (1) year beyond the then applicable  expiration date, and Tenant shall
not have delivered to Landlord,  at least thirty (30) days prior to the relevant
annual  expiration  date, a replacement  Letter of Credit in the amount required
hereunder and otherwise  meeting the requirements set forth above, then Landlord
shall be entitled to draw on the Letter of Credit as provided  above,  and shall
hold and apply the proceeds of such draw as Letter of Credit  Proceeds  pursuant
to Paragraph 17.b above.

     Notwithstanding  the  foregoing,  in the event that Landlord  shall make an
Improvement  Advance as described in Exhibit B attached  hereto,  within  thirty
(30) days of the  determination  of the total amount of the Improvement  Advance
Tenant shall  increase the initial  amount of the Letter of Credit by the amount
of the Improvement Advance.

18. Surrender of Premises.

     By  taking  possession  of the  Premises,  Tenant  shall be  deemed to have
accepted the Premises and the Property in good,  clean and  completed  condition
and  repair,  subiect  to all  applicable  laws,  codes and  ordinances.  On the
Expiration Date or earlier termination of this Lease, Tenant shall surrender the
Premises to Landlord in its condition as of the Commencement  Date,  normal wear
and tear  excepted.  Tenant  shall  remove  from the  Premises  all of  Tenant's
Personal Property and any Alterations required to be removed pursuant to Section
9 of this Lease.  Tenant shall repair any damage or perform any restoration work
required by the removal.  If Tenant fails to timely remove any Personal Property
or Alterations  as aforesaid,  Landlord may remove the property and store and/or
dispose of the same at Tenant's  expense,  including  interest  at the  Interest
Rate. If the Premises are not so surrendered  at the  termination of this Lease,
Tenant  shall  indemnify  Landlord  against all Claims  resulting  from delay by
Tenant in so surrendering  the Premises,  including,  without  limitation,   any
claims  made  by  any  succeeding  tenant,   losses  to  Landlord  due  to  lost
opportunities  to lease to succeeding  tenants,  and attorneys'  fees and costs.
Tenant shall give written  notice to Landlord at least thirty (30) days prior to
vacating the Premises and shall meet with Landlord for a joint inspection of the
Premises at the time of vacating.  In the event of Tenant's failure to give such
notice or  participate  in such joint  inspection,  Landlord's  inspection at or
after Tenant's  vacating the Premises shall  conclusively  be deemed correct for
purposes of determining  Tenant's  responsibility for removal of Alterations and
repairs and restoration of the Premises.

19. Holding Over.

     If Tenant  remains in possession  of all or any part of the Premises  after
the expiration of the Term or the

                                       18
<PAGE>

earlier termination of this Lease without Landlord's prior written consent,  the
tenancy shall be a tenancy at sufferance only and shall not constitute a renewal
or extension for any further term,  regardless of whether  Landlord shall accept
Rent for any such  period.  In such event,  Base Rent shall be  increased  in an
amount  equal to two  hundred  percent  (200%) of the Base Rent  during the last
month of the Term (including any extensions),  and any other sums due under this
Lease shall be payable in the amount, and at the times, specified in this Lease.
The  tenancy  shall be subject to every  other  term,  condition,  covenant  and
agreement  contained in this Lease,  except that any renewal or extension option
in favor of Tenant  shall  not be  applicable.  No such  increase  shall  impair
Landlord's  other rights and remedies  against  Tenant by reason of such holding
over by Tenant, and Tenant shall vacate the Premises immediately upon Landlord's
request.

20. Access to Premises.

     Tenant  shall  permit  Landlord and its agents to enter the Premises at all
reasonable times upon reasonable notice,  except in the case of an emergency (in
which event entry may be made when necessary and without notice), to inspect the
Premises,  to post Notices of Nonresponsibility and similar notices, to show the
Premises to interested  parties such as prospective  mortgagees,  purchasers and
tenants  to  provide  any  services  required  of  Landlord  hereunder,  to make
necessary  alterations,   additions,  improvements  or  repairs  either  to  the
Premises,  the Building, or other premises within the Building, and to discharge
Tenant's  obligations  hereunder  when  Tenant  has  failed  to do so  within  a
reasonable  time  after  written  notice  from  Landlord.  No such  entry  shall
constitute  a  constructive  eviction  or  give  rise  to an  abatement  of Rent
hereunder,  constitute a constructive  eviction,  or otherwise diminish Tenant's
obligations  under this Lease.  In exercising  its rights under this Section 20,
Landlord  shall at all times  endeavor to minimize  interference  with  Tenant's
operations,  to the  extent  practicable.  During  the  last  year of the  Term,
Landlord shall have the right to erect on the exterior of the Premises and/or on
the exterior or in the Common  Areas of the  Building and the Property  suitable
signs indicating that the Premises are available for lease.

21. Signs

     a. The size, design, color, location and other physical aspects of any sign
in or on the Premises shall be subject to the CC&R's, Rules, Landlord's approval
prior to installation, and to all Legal Requirements. The costs df any permitted
sign, and the costs of its  installation,  maintenance and removal,  shall be at
Tenant's sole expense and shall be paid within ten (10) days of Tenant's receipt
of a bill from Landlord for the costs.  In no event shall Tenant be permitted to
place any sign, logo or other identification on the exterior of the Building, in
the Building's  Common Areas (other than on a Building  directory  maintained to
identify the Building's tenants),  or upon the Property,  or which is inside the
Premises but visible  from outside of the Premises  (other than upon the door(s)
to the Premises).

     b. Exterior Building Signage. Notwithstanding Section 21.a., so long as the
Tenant under this Lease (i) is the Tenant  originally  named under this Lease in
the Basic Lease  information,  or any  Affiliate or  Successor of such  original
Tenant,  (ii) is in  occupancy  pursuant to this Lease of at least  seventy-five
percent (75%) of the entire Premises  originally  demised under this Lease,  and
(iii)  is  not  in  default  of any of  its  obligations  hereunder  beyond  the
expiration of any applicable grace or cure period,  Tenant shall be permitted to
maintain  identification signage at the top of one exterior side of the Building
in a location reasonably approved by Landlord. The installation, maintenance and
removal of Tenant's  signage  pursuant to this  Section 21.b. shall be performed
by  Tenant  at  Tenants  expense,  but in  coordination  with  Landlord  and its
reasonable installation procedures and requirements, or at Landlord's option, by
Landlord  at  Tenant's  expense.  Such  signage  of Tenant  shall be  subject to
Landlord's  prior approval and all Legal  Requirements,  and shall be limited to
Tenant's name and/or logo.  If Tenant shall fail to meet the signage  conditions
specified herein,  Landlord may immediately  remove Tenant's signage at Tenant's
expense,  and  Tenant's  signage  rights  pursuant to  this  Section 21.b. shall
thereafter forever cease and terminate;  provided,  however,  that if applicable
Legal  Requirements  do  not  require  removal  of  such  signage  prior  to the
expiration of the thirty (30) day period  hereinafter  provided,  Landlord shall
not remove such signage unless it shall have

                                       19
<PAGE>

given Tenant thirty (30) days' prior notice of the signage conditions Tenant has
failed to meet, and such failure  continues  after the expiration of such thirty
(30) day  period.  Upon the  expiration  or earlier  termination  of this Lease,
Tenant shall, at Tenant's  expense,  or at Landlord's  option Landlord shall, at
Tenant's expense,  remove Tenant's signage and repair any damage to the Building
caused by such removal.

22. Subordination.

     a.  Subordinate  Nature.  Except as provided in Subsections b. and c., this
Lease is subject and subordinate to all ground and underlying leases,  mortgages
and deeds of trust which now or may  hereafter  affect the Real  Property or any
portion   thereof,   to  the  CC&R's,   and  to  all  renewals,   modifications,
consolidations,  replacements  and  extensions  of the  foregoing,  without  the
necessity  of  any  further   documentation   evidencing   such   subordination.
Notwithstanding  such self-operative  subordination,  within ten (10) days after
Landlord's written request therefor,  Tenant shall execute any and all documents
required by Landlord,  the lessor under any ground or underlying  lease ("Ground
Lessor"),  or the holder or holders of any mortgage or deed of trust ("Holder"),
evidencing this Lease to be subordinate to the lien of any such lease,  mortgage
or deed of  trust,  as the  case  may be.  Tenant  hereby  irrevocably  appoints
Landlord as Tenant's attorney-in-fact to execute and deliver any such instrument
in the name of Tenant if Tenant fails to do so within such time. If the interest
of Landlord  in the Real Property or the Building is  transferred  to any Ground
Lessor or Holder  pursuant to or in lieu of proceedings  for  enforcement of any
such  lease,   mortgage,   or  deed  of  trust,  Tenant  shall  immediately  and
automatically  attorn to the  Ground  Lessor or  Holder,  and this  Lease  shall
continue in full force and effect as a direct lease between the Ground Lessor or
Holder and Tenant on the terms and conditions set forth herein.

     b.  Possible  Priority  of Lease.  If a Ground  Lessor or a Holder  advises
Landlord  that it desires or requires  this Lease to be prior and  superior to a
lease,  mortgage or deed of trust,  Landlord may notify Tenant. Within seven (7)
days of Landlord's notice,  Tenant shall execute,  have acknowledged and deliver
to  Landlord  any and all  documents  or  instruments,  in the  reasonable  form
presented to Tenant, which Landlord,  Ground Lessor or Holder deems necessary or
desirable to make this Lease prior and  superior to the lease,  mortgage or deed
of trust.

     c. Lease  Modification.  If, in connection with obtaining financing for the
Real Property or any portion thereof,  any Holder or Ground Lessor shall request
reasonable  modification  to this Lease as a condition  to such ground  lease or
financing, Tenant shall execute and deliver to Landlord, within ten (10) days of
Landlord's request, any such modification agreement so requested,  provided such
modifications  do not  adversely  affect  Tenant's  rights or increase  Tenant's
obligations  hereunder  (other than additional  obligations  requiring Tenant to
send such Holder or Ground Lessor copies of notices given to Landlord).

     d. Nondisturbance  Agreement.  It shall be a condition to the subordination
of this Lease to any Superior  Interest created after the date of this Lease (as
distinguished from any Superior Interest in effect as of the date of this Lease,
or any amendment or  modification  thereto),  that Tenant shall receive from the
Ground Lessor or Holder,  as applicable,  of such Superior  Interest a so-called
non-disturbance  agreement in the form reasonably required by such Ground Lessor
or Holder.

23. Transfer of the Property.

     Upon transfer of the Real Property and  assignment of this Lease,  Landlord
shall be entirely  freed and relieved of all liability  under any and all of its
covenants  and  obligations  contained in or derived  from this Lease  occurring
after the  consummation  of the transfer and  assignment,  and if Landlord shall
transfer the Security  Deposit to the  transferee of Landlord's  interest in the
Real  Property,  Landlord  shall be released from all liability for the Security
Deposit. Tenant shall attorn to any entity purchasing or otherwise acquiring the
Premises at any sale or other proceeding.

                                       20
<PAGE>

24. Estoppel Certificates; Financial Statements.

     Within ten (10) days  following  written  request by Landlord  from time to
time  throughout  the Term,  Tenant  shall  execute  and  deliver to Landlord an
estoppel certificate in the form attached hereto as Exhibit E, duly completed by
Tenant.  At the  request of Landlord  from time to time during the Term,  Tenant
shall provide to Landlord its current financial  statements or other information
setting forth  Tenant's  financial  condition and net worth.  Landlord shall use
such documentation  solely for purposes of this Lease and in connection with the
ownership, financing, management and disposition of the Real Property.

25. Mortgagee Protection.

     In the  event of any  default  on the part of  Landlord,  Tenant  will give
notice by  registered  or certified  mail to each Ground Lessor and Holder whose
identity  has been  disclosed  to Tenant,  and shall offer the Ground  Lessor or
Holder a  reasonable  opportunity  after such  notice (but in no event less than
thirty (30) days) to cure the default,  including  time to obtain  possession of
the Property or the Premises by lease  termination,  power of sale or a judicial
foreclosure (as applicable), if such should prove necessary to effect a cure. In
no event  shall any Ground  Lessor or Holder in any way or to any extent be: (a)
liable for any act or omission of any prior  Landlord  in  contravention  of any
provision of this Lease; or (b) subject to any offsets, claims or defenses which
Tenant  might have  against any prior  Landlord;  or (c) bound by any Rent which
Tenant  might have paid for more than  thirty  (30) days in advance to any prior
Landlord;  or (d) bound by any  agreement  or  modification  of this  Lease made
without such Ground Lessor's or Holder's written consent.  Tenant agrees that if
any Ground Lessor or Holder acquires  possession of the Premises or title to the
Real Property as a result of  termination  of its ground lease or foreclosure of
such Holder's deed of trust or other security  instrument,  as  applicable,  the
acceptance  of a lease  surrender  or deed  in  lieu  of  such  foreclosure,  or
otherwise,  the  provisions of Section 36 below shall be applicable to liability
of such Ground Lessor or Holder as successor Landlord under this Lease.

26. Attorneys' Fees.

     If either party shall bring any action or legal  proceeding for damages for
an alleged breach of any provision of this Lease,  to recover rent or other sums
due,  to  terminate  the  tenancy  of the  Premises  or to  enforce,  protect or
establish  any term,  condition  or  covenant  of this  Lease or right of either
party,  the  prevailing  party shall be  entitled  to recover,  as a part of the
action  or  proceedings,  or in a  separate  action  brought  for that  purpose,
reasonable attorneys' fees and court costs as may be fixed by the court or jury.
The  prevailing  party shall be the party which secures a final  judgment in its
favor,  provided  that if the party  bringing any action shall  dismiss the same
without  the  consent of the other  party,  the other  party shall be deemed the
prevailing party.

27. Brokers.

     Tenant  warrants and  represents  that it has had no dealings with any real
estate broker or agent in connection with the negotiation of this Lease,  except
for the brokers(s) specified in the Basic Lease Information (the "Brokers"), and
that it  knows of no  other  real  estate  broker  or  agent  who is or might be
entitled to a fee,  commission or  other  compensation  in connection  with this
Lease.  Tenant shall  indemnify and hold harmless  Landlord from and against any
and all liabilities or expenses (including reasonable attorneys' fees and costs)
arising out of claims made by any broker or individual  (other than the Brokers)
for a fee, commission or other compensation  resulting from this Lease. Pursuant
to the terms of separate agreement(s) between Landlord and the Brokers, Landlord
shall pay the Brokers any fee,  commission or other  compensation  to which they
are  entitled  from  Landlord  by reason of this  Lease.  Tenant  shall  have no
liability to the Brokers for any fee, commission or other compensation.

                                       21
<PAGE>

28. Parking

     Tenant shall have the right to park in the Building's  parking  facilities,
in common with other tenants of the Building,  upon such terms and conditions as
may from time to time be established  by Landlord.  There shall be no charge for
any portion of the parking  facilities which is not reserved.  Tenant agrees not
to use in excess of its proportionate share (i.e. the rentable square footage of
the Premises in  proportion  to the rentable  square  footage of the Building or
Buildings served by such parking facilities) of parking facilities and agrees to
cooperate with Landlord and other tenants in the use of the parking  facilities.
Landlord reserves the right in its absolute discretion, to determine whether the
parking  facilities  are  becoming  crowded and to allocate  and assign  parking
spaces  among  Tenant  and the other  tenants.  Landlord  shall not be liable to
Tenant,  nor shall  this  Lease be  affected,  if any  parking  is  impaired  by
moratorium,  initiative,  referendum,   law,  ordinance,  regulation   or  order
passed, issued or made by any governmental or quasi-governmental body or by fire
or other casualty.

29. Utilities and Services.

     Tenant shall arrange for all telephone,  water, gas,  electricity and other
power  and  utilities  which  it shall  require  in  connection  with its use or
occupancy of the Premises and shall pay for the same,  together  with any taxes,
penalties,  surcharges or the like  pertaining  thereto.  Landlord shall have no
obligation to furnish any utilities or services to the Premises or any equipment
providing for the same. Without  limitation,  Tenant shall be solely responsible
for providing such heating,  ventilation  and air  conditioning  ("HVAC") to the
Premises as Tenant shall  require for the  comfortable  occupancy  thereof.  Any
equipment or systems which Tenant shall require in order to supply HVAC shall be
subject  to the  provisions  of Section 9 above.  Tenant  shall  obtain,  at its
expense all electric light bulbs, ballasts and tubes as it shall require for the
Premises.  If any of the  foregoing  utilities  or services  are not  separately
metered to Tenant,  Tenant shall pay a reasonable  proportion,  as determined by
Landlord,  of all charges  jointly  serving  the  Premises  and other  premises.
Landlord  shall not be liable for any damages  directly or indirectly  resulting
from nor shall the Base Rent,  Operating  Expenses  or any other  monies owed by
Tenant to  Landlord  under  this Lease be abated or reduced by reason of (a) the
installation,  use or  interruption  of use of any equipment  used in connection
with the furnishing of any of the foregoing utilities and services,  (b) failure
to furnish or delay in furnishing  any such utilities or services for any reason
whatsoever, or (c) the limitation,  curtailment, rationing or restriction on use
of water,  electricity,  gas or any other form of energy or any other service or
utility whatsoever serving the Premises or the Real Property.  Landlord shall be
entitled to cooperate voluntarily and in a reasonable manner with the efforts of
national,  state or local government  agencies or utility  suppliers in reducing
energy or other resource consumption.  The obligation to make services available
hereunder shall be subject to the limitations of any such voluntary,  reasonable
program.

30. Intentionally Deleted.

31. Acceptance.

     Delivery of this Lease, duly executed by Tenant, constitutes Tenant's offer
to lease the Premises as set forth herein, and under no circumstances shall such
delivery be deemed to create an option or  reservation to lease the Premises for
the benefit of Tenant.  This Lease shall become  effective and binding only upon
execution  hereof by  Landlord  and  delivery  of a signed  copy to  Tenant.  If
Landlord does not accept the Tenant's  offer,  any sums delivered by Tenant with
its offer shall be returned to Tenant.

32. Use of Building Name.

     Tenant  shall not employ the name of the  Building  in the name or title of
its business or  occupation,  or for any other  purpose,  except to identify the
address of the Building, without Landlord's prior written consent, which consent
Landlord may  withhold in its sole  discretion.  Landlord  reserves the right to
change the name

                                       22
<PAGE>

of the Building without Tenant's consent and without any liability to Tenant.

33. Recording.

     Neither  Landlord  nor Tenant  shall  record this  Lease,  nor a short form
memorandum of this Lease, without the prior written consent of the other.

34. Quitclaim.

     Upon any  termination  or expiration  of this Lease  pursuant to its terms,
Tenant, at Landlord's request,  shall execute,  have acknowledged and deliver to
Landlord a quitclaim deed of all Tenant's interest in the Premises, Building and
Property created by this Lease.

35. Notices.

     Any  notice,  demand or request  required or desired to be given under this
Lease  shall be in writing  sent to the address of the party  specified  in this
Lease,  and shall be given by hand delivery,  electronic mail (e.g.,  telecopy),
overnight  courier  service (e.g.  Federal  Express), or the United States mail,
registered or  certified,  the postage  prepaid.  All notices shall be deemed to
have been given when  received  at the address of the party to which it has been
sent (or when such  receipt is  refused).  As of the date of  execution  of this
Lease,  the addresses of Landlord and Tenant are as specified in the Basic Lease
Information.  Either party may change its address by giving notice of the change
in accordance with this Section.

36. Landlord's Exculpation.

     The term  "Landlord,"  as used in this Lease,  shall mean only the owner or
owners of the Real Property at the time in question.  Notwithstanding  any other
provision of this Lease,  the  liability of Landlord for its  obligations  under
this Lease is limited solely to Landlord's  interest in the Real Property as the
same may from time  to time be encumbered,  and no personal  liability  shall at
any time be asserted  or  enforceable  against  any other  assets of Landlord or
against the constituent  shareholders,  partners or other owners of Landlord, or
the directors,  officers,  employees and agents of Landlord or such  constituent
shareholder, partner or other owner, on account of any of Landlord's obligations
or actions under this Lease.  Notwithstanding any other provision of this Lease,
Landlord shall not be liable for any  consequential  damages or  interruption or
loss of business, income or profits, nor shall Landlord be liable for loss of or
damage to artwork,  currency,  jewelry,  bullion,  unique or valuable documents,
securities  or other  valuables,  or for  other  property  not in the  nature of
ordinary fixtures,  furnishings and equipment. Wherever in this Lease Tenant (a)
releases Landlord from any claim or liability, (b) waives or limits any right of
Tenant to assert any claim  against  Landlord  or to seek  recourse  against any
property of Landlord or (c) agrees to  indemnify  Landlord  against any matters,
the relevant release, waiver,  limitation or indemnity shall run in favor of and
apply to Landlord,  the  constituent  shareholders,  partners or other owners of
Landlord, and the directors, officers, employees and agents of Landlord and each
such  constituent  shareholder,  partner or other  owner.  In no event shall any
shareholder, partner, member, officer, director or other constituent of Landlord
or its direct or indirect  constituents ever be personally liable for Landlord's
obligations or liability under this Lease.

37. Additional Structures.

     Any  diminution or  interference  with light,  air or view by any structure
which may be erected on land adjacent to the Building shall in no way alter this
Lease or impose any liability on Landlord.

                                       23
<PAGE>

38. Consents and Approvals.

     Wherever the consent,  approval,  judgment or  determination of Landlord is
required or  permitted  under this Lease,  except as expressly  provided  herein
Landlord  may  exercise  its sole  discretion  in granting or  withholding  such
consent or approval or in making such judgment or determination. Whenever Tenant
requests  Landlord  to take any action or give any consent or  approval,  Tenant
shall reimburse  Landlord for all of Landlord's  costs incurred in reviewing the
proposed  action  or  consent  (whether  or not  Landlord  consents  to any such
proposed  action),  including,  without  limitation,  reasonable  attorneys'  or
consultants' fees and expenses,  within ten (10) days after Landlord's  delivery
to Tenant of a statement of such costs. If it is determined that Landlord failed
to give its consent or approval where it was required to do so under this Lease,
Tenant's  sole  remedy  will be an order of specific  performance  or  mandatory
injunction  of the  Landlord's  agreement to give its consent or  approval.  The
review  and/or  approval by Landlord of any item shall not impose upon  Landlord
any  liability  for accuracy or  sufficiency  of any such item or the quality or
suitability  of such item for its  intended  use. Any such review or approval is
for the sole purpose of protecting Landlord's interest in the Real Property, and
neither  Tenant  nor any  Tenant  Party nor any  person or entity  claiming  by,
through  or under  Tenant,  nor any other  third  party  shall  have any  rights
hereunder by virtue of such review and/or approval by Landlord.

39. General.

     a.  Captions.  The  captions  and  headings  used in this Lease are for the
purpose of  convenience  only and shall not be  construed to limit or extend the
meaning of any part of this Lease.

     b. Time. Time is of the essence for the performance of each term, condition
and covenant of this Lease.

     c.  Severability.  If any  provision  of this Lease is held to be  invalid,
illegal or unenforceable, the invalidity,  illegality, or unenforceability shall
not affect any other provision of this Lease,  but this Lease shall be construed
as if the invalid,  illegal or  unenforceable  provision had not been  contained
herein.

     d. Choice of Law; Construction.  This Lease shall be construed and enforced
in  accordance  with the laws of the State of  California.  The  language in all
parts of this Lease shall in all cases be construed as a whole  according to its
fair meaning and not strictly for or against either Landlord or Tenant.

     e. Gender;  Singular,  Plural. When the context of this Lease requires, the
neuter gender includes the masculine, the feminine, a partnership or corporation
or joint venture, and the singular includes the plural.

     f. Binding  Effect.  The covenants and  agreements  contained in this Lease
shall be binding on the  parties  hereto  and,  subject to Section 14 above,  on
their respective successors and assigns.

     g. Waiver.  The waiver of Landlord of any breach of any term,  condition or
covenant  of this Lease shall not be deemed to be a waiver of the  provision  or
any  subsequent  breach of the same or any other term,  condition or covenant of
this Lease. The subsequent acceptance of Rent hereunder by Landlord shall not be
deemed to be a waiver of any  preceding  breach at the time of acceptance of the
payment.  No  covenant,  term or condition of this Lease shall be deemed to have
been waived by Landlord unless the waiver is in writing signed by Landlord.

     h.  Entire  Agreement.  This  Lease is the  entire  agreement  between  the
parties,  and  supersedes  all prior  agreements,  including  letters of intent,
between them, and there are no agreements or representations between the parties
except as expressly set forth herein.  Except as otherwise  provided herein,  no
subsequent  change or addition to this Lease shall be binding  unless in writing
and signed by the parties hereto.

                                       24
<PAGE>

     i.  Waiver of Jury.  Tenant  hereby  waives any right it may have to a jury
trial in the event of litigation between Tenant and Landlord  pertaining to this
Lease.  Landlord  and Tenant  agree that this  paragraph  constitutes  a written
consent to waiver of trial by jury within the meaning of Califomia Code of Civil
Procedure  Section 631 (a)(2),  and Tenant  does  hereby  authorize  and empower
Landlord to file this paragraph and or this Lease,  as required,  with the clerk
or judge of any court of competent  jurisdiction  as a written consent to waiver
of jury trial.

     j. Counterparts.  This Lease may be executed in counterparts, each of which
shall  be an  original,  and all of  which  together  shall  constitute  but one
instrument.

     k. Exhibits.  The Basic Lease  Information and all exhibits attached hereto
are hereby incorporated herein and made an integral part hereof.

     l. Addendum.  The Addendum,  if any, attached hereto is hereby incorporated
herein and made an integral part hereof.

     m. Other Leases.  Tenant represents and warrants to Landlord that, with the
exception of this Lease,  neither Tenant nor any affiliate of Tenant is a tenant
under a lease or any other  tenancy  agreement  (1) with (a) Riggs & Company;  a
division of Riggs Bank N.A., as trustee of the  Multi-Employer  Property  Trust,
(b) Riggs Bank N.A., as trustee of the  Multi-Employer  Property Trust,  (c) the
Multi-Employer   Property   Trust,   (d)  the   National   Bank  of   Washington
Multi-Employer  Property Trust, the previous name of the Multi-Employer Property
Trust,  (e) The Riggs  National  Bank of  Washington,  D.C.,  as  trustee of the
Multi-Employer  Property  Trust,  (f)  North-ridge  Business Center LLC, (g) the
Corporate  Drive  Corporation,  as trustee of the Corporate Drive Nominee Realty
Trust, (h) Arboretum Lakes-I,  L,L.C., a Delaware limited liability company, (i)
Village Green at Seven Bridges, L.L.C., (j) Pine Street Development, L.L.C., (k)
MEPT Realty LLC, a New York limited  liability  company,  (1) MIEPT,  L.L.C.,  a
Delaware limited liability  company,  (m) Cabrillo  Properties LLC, (n) Valencia
LLC, (o) Mission Trails LLC, or (p) Centrepointe Distribution Center LLC, or (2)
involving any property in which any one or more of the entities named in clauses
(1)(a) through (e) are known by Tenant to have an ownership interest.

40. Renewal Option.

     a. Tenant shall have the option to renew this Lease for one (1)  additional
term of five (5) years,  commencing  upon  expiration of the initial Term.  Such
renewal  option must be exercised,  if at all, by written notice given by Tenant
to Landlord  not later than nine (9) months prior to  expiration  of the initial
Term.  Notwithstanding the foregoing, this renewal option shall be null and void
and  Tenant  shall  have no  right  to  renew  this  Lease if (i) as of the date
immediately preceding the commencement of the renewal period the original Tenant
named under this Lease in the Basic Lease Information is not in occupancy of the
entire  Premises  then  demised  hereunder  or such  Tenant  does not  intend to
continue to occupy the entire  Premises then demised  hereunder  (but intends to
assign this Lease or sublet the  Premises  in whole or in part),  or (ii) on the
date Tenant exercises such renewal option or on the date  immediately  preceding
the  commencement  date of the renewal period Tenant is in default of any of its
obligations under this Lease.

     If Tenant exercises such renewal option, then during the renewal period the
Base Rent  payable by Tenant shall be the then fair market rent for the Premises
based upon the terms of this Lease, as renewed. For purposes of this Section 40,
the term "fair  market  rent"  shall mean the rental rate for  comparable  space
under primary lease (and not sublease) to new tenants, taking into consideration
such amenities as existing  improvements,  view, floor on which the Premises are
situated and the like,  situated in comparable  first-class  office buildings in
comparable business parks in a fifteen (15) mile radius of the Property,  taking
into  consideration  the  then-prevailing  ordinary rental market practices with
respect to tenant concessions (if any) (e.g. not offering  extraordinary rental,
promotional  deals and other  concessions  to tenants which deviate from what is
the  then-prevailing  ordinary  practice  in an  effort to  alleviate  cash flow
problems, difficulties

                                       25
<PAGE>

in meeting loan  obligations or other  financial  distress,  or in response to a
greater than average vacancy rate).  Fair market rent shall include the periodic
rental  increases,  if any,  that  would be  included  for space  leased for the
renewal  period.  The fair market rent shall be mutually agreed upon by Landlord
and Tenant in writing  within the thirty  (30)  calendar  day period  commencing
three (3) months prior to commencement  of the renewal  period.  If Landlord and
Tenant do not agree  upon the fair  market  rent  within  said  thirty  (30) day
period,  then  the fair  market  rent  shall  be  established  by  appraisal  in
accordance with the procedures set forth in Exhibit F attached hereto.

     b.  Notwithstanding  anything  in  the  foregoing  or in  Exhibit  F to the
contrary, in no event shall the Base Rent during the renewal period be less than
the Base  Rent  payable  by  Tenant  for the  month  immediately  preceding  the
commencement of the renewal period (without regard to any temporary abatement of
rental then in effect pursuant to the provisions of this Lease).

         IN WITNESS  WHEREOF,  the parties have executed this Lease on the dates
set forth below, effective as of the date first above wntten.

Landlord:                               Tenant:

THE MULTI-EMPLOYER                      CERTICOM CORP.,
PROPERTY TRUST, A TRUST                 a Delaware corporation
ORGANIZED UNDER 12 C.F.R.
SECTION 9.18, by its trustee            By:  /s/ Philip C. Deck
Riggs & Company, a division of               --------------------------
Riggs Bank N.A.
                                        Its: Chairman + CEO
                                             --------------------------

By: /s/ Mary Anne Martins               By: /s/ B. MacInnis
    ---------------------------             ---------------------------
    Mary Anne Martins

Its:  Managing Director                 Its: Vice President + CFO
     --------------------------              --------------------------

                                       26
<PAGE>

                                   EXHIBIT A
                                   ---------

                             Mt. Eden Business Park
                                  Hayward, CA

                                Graphic Omitted

<PAGE>

                                    EXHIBIT B
                                    ---------

                               TENANT IMPROVEMENTS
                               -------------------

         1. Tenant Improvements.

         a.  Plans.  Improvements  shall  be  constructed  in  the  Premises  in
accordance  with this Paragraph 1. On or before  October 27, 1998,  Tenant shall
furnish to Landlord for Landlord's review and approval (which approval shall not
be unreasonably  withheld) detailed layout plans and finish  specifications (the
"Space Plans")  prepared by an architect  approved by Landlord.  The Space Plans
shall show all of the improvements which Tenant desires to be constructed in the
Premises,  and all such improvements  shall comply with all applicable  building
codes and other Legal  Requirements.  The Space Plans shall  separately note any
proposed structural work or extraordinary or supplemental  electrical,  plumbing
or HVAC requirements,  and shall contain such detail and specifications as would
permit a general  contractor  to  obtain  preliminary  estimates  of the cost of
performing  all  work  shown  thereon.  Tenant  shall  respond  promptly  to any
reasonable  objections  of  Landlord  to the  Space  Plans  and  shall  resubmit
appropriately  revised Space Plans prepared by Tenant's  architect  within three
(3) Business Days of Tenant's receipt of Landlord's objections. The Space Plans,
as finally  approved in writing by Landlord,  shall be referred to herein as the
"Final  Space  Plans."  Landlord  shall  furnsh to Tenant for  Tenant's  written
approval  (which  shall  not  be  unreasonably   withheld)   working  plans  and
specifications (the "Working Drawings") prepared by Landlord's architect for the
improvements which Tenant desires to be constructed in the Premises. The Working
Drawings shall show  improvements  that conform to the Final Space Plans (except
to the extent  specifically  noted therein or in  accompanying  specifications).
Tenant shall respond to the Working  Drawings  within three (3) Business Days of
its  receipt  thereof.   Landlord  shall  respond  promptly  to  any  reasonable
objections  of Tenant to the Working  Drawings and shall  resubmit to Tenant for
Tenant's  approval  (which  shall not be  unreasonably  withheld)  appropriately
revised Working Drawings prepared by Landlord's architect.  Tenant shall respond
to the revised  Working  Drawings  within three (3) Business Days of its receipt
thereof.  If Tenant  falls to respond to the  Working  Drawings  or the  revised
Working Drawings within the periods  described above,  Tenant shall be deemed to
have approved the Working Drawings or revised Working  Drawings,  as applicable.
The Working Drawings,  as approved in writing by Landlord and Tenant, as revised
in accordance with the following provisions of this Paragraph 1, are hereinafter
called the "Final  Plans",  and the  improvements  to be performed in accordance
with the Final Plans are hereinafter called the "Tenant Improvements". Any delay
in Substantial  Completion of the Tenant  Improvements  or increased cost of the
Tenant  Improvements  caused directly or indirectly by any revision to the Space
Plans or the Working  Drawings  requested  by Tenant  shall  constitute a Tenant
Delay under Paragraph 1.e. below.

         b.  Construction.  Upon  approval of the Final  Plans,  Landlord  shall
submit the same for pricing to a  contractor  selected by Landlord  ("Landlord's
Contractor"),  and thereafter  provide  Tenant with an estimated  budget for the
Tenant  Improvements,  including  Landlord's  Construction  Operations  Fee  (as
defined in  Paragraph 1.f.iii.B.  below).   Tenant  shall have five (5) Business
Days after the receipt of Landlord's  estimated  budget to approve or reasonably
disapprove of the same. If Tenant disapproves of the budget within such five (5)
Business Day period,  Tenant shall so notify  Landlord and the Final Plans shall
promptly be modified by Landlord's  architect in order to satisfactorily  reduce
the  amount  of the  estimated  budget,  as  requested  by  Tenant.  Any and all
revisions  to the Final  Plans  shall be  subject  to  Landlord's  and  Tenant's
reasonable approval. Upon Landlord's revision of the Final Plans, Landlord shall
cause  Landlord's  Contractor to promptly  issue new pricing and upon receipt of
such pricing  Landlord  shall  prepare and submit to Tenant a revised  estimated
budget.  Tenant  shall  respond to the  revised  estimated  budget in the manner
described above. Any delay in Substantial  Completion of the Tenant Improvements
or increased cost of the

                                       1
<PAGE>

Tenant  Improvements  caused directly or indirectly by any revision to the Final
Plans or the estimated budget to address  Tenant's  disapproval of the estimated
budget shall  constitute a Tenant Delay under  Paragraph 1.e.  below.  If Tenant
fails to raise any  objections  to the budget  within the five (5)  Business Day
period(s)  described above,  Tenant shall be deemed to have approved  Landlord's
proposed budget. Landlord shall commence construction of the Tenant Improvements
promptly after approval of the Final Plans,  and  thereafter  diligently  pursue
such  construction  to completion (but in no event shall Landlord be required to
pursue a construction schedule which would cause Substantial Completion to occur
prior to January 15, 1999).  Landlord shall use reasonable care in preparing the
budget,  but it shall be a good faith  estimate only and will not limit Tenant's
obligation to pay for its share of the costs of the Tenant  Improvements  as set
forth below in this Paragraph 1.

         c. Changes.  In the event that Tenant shall request any change in or to
the Final Plans (a "Change"),  Landlord's architect shall prepare for Landlord's
and  Tenant's  review and written  approval a change  order with respect to such
Change (the "Change  Order"),  together with, if  appropriate,  revised  Working
Drawings  incorporating the requested Change and clearly identifying the same as
such on the revised Working Drawings.  Landlord shall not unreasonably  withhold
or delay its approval of the Change Order or revised Working Drawings, provided,
however, that Landlord shall have at least three (3) Business Days after receipt
thereof to review any proposed Change.  In the event that Landlord shall approve
any proposed  Change,  together with such approval,  if practicable,  and if not
practicable  as soon  thereafter as is  practicable,  Landlord shall give Tenant
Landlord's estimated increase or decrease in the cost of the Tenant Improvements
which would result from incorporating such Change and Landlord's estimate of the
delay,  if any, in the  commencement  or completion  of the Tenant  Improvements
which would result from incorporating such Change.  Landlord will use reasonable
care in preparing the estimates, but they shall be good faith estimates only and
will not limit Tenant's obligation to pay for the actual increase in the cost of
the Tenant  Improvements or Tenant's  responsibility for the actual construction
delay  resulting from the Change.  Within two (2) Business Days after receipt of
such cost and delay  estimates,  Tenant shall notify Landlord in writing whether
Tenant  approves the Change.  If Tenant fails to approve the change  within such
two (2)  Business  Day period,  construction  of the Tenant  Improvements  shall
proceed as provided in accordance  with the Final Plans as they existed prior to
the requested Change.  If, following  Tenant's review of the estimated costs and
delays,  Tenant  desires  Landlord  to  incorporate  the Change  into the Tenant
Improvements,  then Tenant and  Landlord  shall  execute a change order for such
Change on Landlord's  standard form  therefor,  and the term "Final Plans" shall
thereafter  be  deemed  to refer  to the  Working  Drawings  as so  revised  and
approved.

         d.  Landlord's   Work.  In  addition  to  construction  of  the  Tenant
Improvements,  Landlord shall construct the Building as a watertight shell, with
all utilities  brought to the Building,  in  accordance  with plans  prepared by
Landlord's   architect  and  previously   delivered  to  Tenant   (collectively,
"Landlord's  Work").  Landlord's Work shall be performed at Landlord's sole cost
and expense  (except for any costs  resulting from Tenant Delays,  including any
Changes) by such general contractor as Landlord shall determine.

         e. Tenant  Delays.  Tenant shall be  responsible  for, and shall pay to
Landlord,  any and all costs and  expenses  (including  lost rent)  incurred  by
Landlord  in  connection  with the  following,  or by reason of any delay in the
commencement or completion of Landlord's  Work or the Tenant  Improvements or in
Landlord's  timely  delivery of the Premises  caused by the  following:  (i) the
failure of Tenant to submit the Space  Plans or Final Space Plans to Landlord by
the dates or within the time periods set forth in Paragraph l.a.  above,  or the
failure  of the  Space  Plans  or  Final  Space  Plans  to meet  the  applicable
requirements  of Paragraph l.a. above,  (ii) Tenant's  failure to respond to the
Working  Drawings  within the time period(s) set forth in Paragraph l.a.  above,
(iii) any changes in the Space Plans requested by Tenant,  or any changes in the
Working  Drawings  requested by Tenant  (including any costs or delays resulting
from proposed changes that are not ultimately

                                       2
<PAGE>

made), (iv) any failure by Tenant to promptly respond to inquiries regarding the
construction of the Tenant  Improvements or Landlord's Work or to promptly grant
Tenant's  approval of  materials  or  finishes  for the Tenant  Improvements  or
Landlord's  Work,  (v) any  failure by Tenant to timely pay any amounts due from
Tenant  hereunder  (it  being  acknowledged  that  if  Tenant  fails  to make or
otherwise delays making such payments,  Landlord may stop Landlord's Work rather
than incur costs which  Tenant is  obligated to fund but has not yet done so and
any  delay  from  such a  work  stoppage  will  be a  Tenant  Delay),  (vi)  any
interference  by Tenant  with the  construction  of the Tenant  Improvements  or
Landlord's  Work,  or (vii)  any other  delay  requested  or  caused by  Tenant,
including, without limitation, any delay caused by Tenant's early entry into any
portion of the  Premises  pursuant  to Section  2.d.  of the Lease.  Each of the
foregoing is referred to herein and in the Lease as a "Tenant Delay".

         Landlord   shall   notify   Tenant  in  writing  of  any  Tenant  Delay
(identifying  the nature of the Tenant Delay) as soon as reasonably  practicable
after  Landlord  becomes  actually  aware of such Tenant  Delay,  together  with
Landlord's  then good faith  estimate  of the  probable  duration of such Tenant
Delay.  Without  limitation,  Landlord will use its good faith efforts to notify
Tenant of "long lead items" as soon as  reasonably  practicable  after  actually
being  advised of the delay by the  suppliers  involved,  or otherwise  actually
becoming  aware of the delay.  Landlord  will  suggest  alternative  products to
alleviate  the delay,  if possible,  and may  substitute  reasonably  equivalent
products as deemed reasonably necessary by Landlord.

         f. Cost of Improvements.  The cost of the construction and installation
of the Tenant Improvements shall be borne as follows:

                  1. Landlord  shall pay the entire cost of Landlord's  Work (as
         described  in  Paragraph 1.d.  above),  including   costs of  obtaining
         permits for the same.

                  ii. Landlord's architectural, engineering and other consultant
         fees in  connection  with the  design  and  construction  of the Tenant
         Improvements, including the costs of producing the Working Drawings and
         Final Plans, shall be paid by Tenant upon Landlord's demand, subject to
         Tenant's right to use a portion of Landlord's  Contribution towards the
         amount of such costs as provided below.

                  iii.   Landlord  shall  contribute  toward  the  cost  of  the
         construction and installation of the Tenant  Improvements an amount not
         to  exceed  $857,100.00  (which  is the  product  of  $20.00  times the
         stipulated  number of rentable square feet of the Premises as set forth
         in  the  Basic  Lease  Information)  ("Landlord's  Contribution").  The
         following   provisions   shall   govern  the  payment   of   Landlord's
         Contribution:

                           A. Excess Cost;  Share of Costs. If the total cost of
         construction  of the Tenant  Improvements  (including the  Construction
         Operations  Fee  described  below  and  the  City  of  Hayward  Interim
         Supplemental  Building  Construction  and Improvement  Tax) exceeds the
         funds  available  therefor from  Landlord's  Contribution,  then Tenant
         shall pay all such excess (the "Excess  Cost").  Based on the estimated
         cost  (the  "Estimated  Costs")  of  the  construction  of  the  Tenant
         Improvements,  the  prorata  share of the  Estimated  Costs  payable by
         Landlord and Tenant shall be determined and an  appropriate  percentage
         share  established  for each (a "Share of Costs").  Tenant and Landlord
         shall  fund  the  cost  of  such  work as the  same  is  performed,  in
         accordance with their  respective Share of Costs for such work. At such
         time as Landlord's  Contribution  has been entirely  disbursed,  Tenant
         shall pay the remaining  Excess Cost, if any,  which  payments shall be
         made in installments as

                                       3
<PAGE>

         construction  progresses  in the same  manner as  Tenant's  payments of
         Tenant's Share of Costs were paid.

                           B. Construction Operations Fee. Landlord shall retain
         from the amount of  Landlord's  Contribution,  in the manner  described
         below, an aggregate sum equal to four percent (4%) of the total cost of
         the  construction and  installation of the Tenant  Improvements  (which
         cost of the construction and installation  shall include  architectural
         and   engineering   fees  but  shall  not  include  permit  fees)  (the
         "Construction  Operations  Fee") as compensation to Landlord for review
         of plans,  specifications  and budgets,  coordinating  the schedule for
         construction of the Tenant  Improvements,  and for other  miscellaneous
         costs incurred by Landlord as a result of the construction work. At the
         time  Landlord  makes  any  disbursement  of  Landlord's  Contribution,
         Landlord  shall  retain  from  Landlord's  Contribution,  as a  partial
         payment of the Construction  Operations Fee, a proportionate  amount of
         the  Construction  Operations  Fee  based  upon  Landlord's  reasonable
         estimate of the amount  required to be withheld from such  disbursement
         in order to  ensure  that the  entire  Construction  Operations  Fee is
         retained over the course of  construction  on a prorata basis.  At such
         time as Landlord's  Contribution  has been entirely  disbursed,  if the
         entire  Construction  Operations Fee has not yet been paid to Landlord,
         Tenant shall pay to Landlord a prorata  portion of each payment made by
         Tenant on account of the Tenant  Improvements  in order to ensure  that
         the balance of the Construction Operations Fee is paid to Landlord over
         the course of construction on a prorata basis.

                           C. Certain Costs. Portions of Landlord's Contribution
         may, at Tenant's  election,  be applied toward  Tenant's  architectural
         fees in  connection  with the  production  of the Space Plans and Final
         Space  Plans,  and  Landlord's  architectural,  engineering  and  other
         consultant fees in connection  with the design and  construction of the
         Tenant  Improvements,  including  the costs of  producing  the  Working
         Drawings  and Final  Plans;  provided,  however,  that the  portion  of
         Landlord's  Contribution applied to such fees may not exceed One Dollar
         ($1.00) per  rentable  square foot of the Premises and any excess shall
         be paid directly by Tenant to Landlord  from Tenant's own funds.  In no
         event may any portions of Landlord's  Contribution  be applied  towards
         the  costs of  Tenants  engineering  fees  (if  any),  trade  fixtures,
         personal  property,  equipment or furniture,  or towards rent due under
         this Lease.

                           D.   Entire   Premises   to   be   Improved.   Tenant
         acknowledges  that  Landlord's  Contribution  is to be  applied  to the
         Tenant   Improvements   (and   the  costs   permitted  under  Paragraph
         1 .f.iii.C.  above)  covering the entire  Premises.  If Tenant does not
         improve the entire  Premises,  then,  without  limitation  of any other
         rights or remedies of Landlord hereunder, Landlord's Contribution shall
         be adjusted on a prorata per rentable  square foot basis to reflect the
         number of rentable square feet actually being improved.

                           E.  Provisions  Applicable  to Phases.  Landlord  and
         Tenant  acknowledge  that the Premises may be improved by Tenant in two
         phases  based  on  Tenant's  anticipated  occupancy  schedule  for  the
         Premises.  Accordingly, the foregoing provisions shall apply separately
         as to each phase of the Premises,  and where the  foregoing  provisions
         refer to the "Premises",  such reference shall be deemed a reference to
         the applicable phase of the Premises.

                  iv.  Improvement   Advance.   Notwithstanding   the  foregoing
         provisions,  if  the  cost  of the  Tenant  Improvements  shall  exceed
         Landlord's  Contribution,  upon Tenant's request Landlord shall advance
         to Tenant the Excess Cost, up to a total

                                       4
<PAGE>

         advance of $299,985.00  (which is $7.00 per rentable square foot of the
         Premises).  The amount of the total  Excess  Cost  advanced by Landlord
         (the  "Improvement  Advance") shall be repaid by Tenant,  together with
         interest  on amounts  thereof  from time to time  unpaid at the rate of
         eleven  percent  (11%) per  annum,  in equal  monthly  installments  of
         principal and interest, as additional rent hereunder,  payable with the
         monthly Basic Rent. Such  installments  shall be in such amount as will
         fully  amortize the amount of the  Improvement  Advance,  together with
         such interest,  over the initial Term.  Upon the  determination  of the
         amount of the Improvement  Advance,  Landlord and Tenant shall promptly
         execute  a  written  memorandum  of the  amount  of such  installments.
         Notwithstanding anything in the foregoing to the contrary, in the event
         this Lease is terminated prior to the originally  scheduled  Expiration
         Date,  for any  reason  whatsoever,  the  then-outstanding  balance  of
         Improvement Advance, together with accrued and unpaid interest thereon,
         but without any prepayment  penalty,  shall become  immediately due and
         payable in full by Tenant.

                                       5
<PAGE>

                                    EXHIBIT C
                                    ---------

                          COMMENCEMENT DATE MEMORANDUM
                          ----------------------------

LANDLORD:   __________________________
            __________________________

TENANT:     __________________________
            __________________________

LEASE DATE: __________________________

PREMISES:   __________________________
            __________________________
            __________________________

Pursuant to Section 2.d. of the  above-referenced  Lease, the Commencement  Date
hereby is established as ___________________,  and the Expiration Date hereby is
established as ___________________.

                     LANDLORD:
                     __________________________
                     a ________________________

                     By _______________________
                        Its ___________________

                     TENANT:
                     __________________________
                     a ________________________

                     By _______________________
                        Its ___________________

<PAGE>

                                   EXHIBIT D
                                   ---------

                              RULES AND REGULATIONS
                              ---------------------

1. No sign, placard, picture,  advertisement,  name or notice shall be installed
or displayed  on any part of the outside or inside of the  Building  without the
prior written consent of Landlord.  Landlord shall have the right to remove,  at
Tenant's  expense  and  without  notice,  any sign  installed  or  displayed  in
violation of this rule.  All approved  signs or lettering on doors,  windows and
walls shall be printed,  painted,  affixed or inscribed at the expense of Tenant
by a person chosen by Landlord,  using  materials of Landlord's  choice and in a
style and format approved by Landlord.

2. The directory of the Building will be provided exclusively for the display of
the name and location of tenants, and Landlord reserves the right to exclude any
other names therefrom.  Tenant shall pay Landlord's standard charge for Tenant's
listing thereon and for any changes by Tenant.

3. Except as consented to in writing by Landlord or in accordance  with Building
standard improvements, no draperies,  curtains, blinds, shades, screens or other
devices shall be hung at or used in, connection with any window or exterior door
or doors of the  Premises.  No  awning  shall  be  permitted  on any part of the
Premises.  Tenant shall not place anything  against or near glass  partitions or
doors or windows which may appear unsightly from outside the Premises.

4. Tenant shall not obstruct any sidewalks,  halls,  lobbies,  passages,  exits,
entrances,  elevators or stairways of the Building. No tenant and no employee or
invitee of any tenant shall go upon the roof of the Building or make any roof or
terrace  penetrations.  Tenant  shall  not  allow  anything  to be placed on the
outside terraces or balconies without the prior written consent of Landlord.

5. No Tenant shall invite to the  Premises,  or permit the visit of,  persons in
such numbers or under such conditions as to interfere with the use and enjoyment
of the Common Areas of the Building by other tenants.

6. Intentionally Deleted.

7. Landlord will furnish Tenant,  free of charge, two (2) keys to Tenant's suite
entrance.  Landlord may make a reasonable charge for any additional keys and for
having any locks  changed.  Tenant shall not make or have made  additional  keys
without Landlord's prior written consent, and Tenant shall not alter any lock or
install  a new  additional  lock  or bolt on any  door of its  Premises  without
Landlord's  prior written  consent.  Tenant shall deliver to Landlord,  upon the
termination of its tenancy, the keys to all locks for doors on the Premises.  If
Tenant loses any keys furnished by Landlord,  Tenant shall pay Landlord the cost
of rekeying the Premises.

     Landlord  will furnish  Tenant,  free of charge,  two (2)  building  access
cards. A reasonable charge will be assessed for any additional cards and lost or
stolen cards.  Tenant shall  deliver to Landlord,  upon the  termination  of its
tenancy, all access cards.

8.  If  Tenant  requires  telegraphic,  telephonic,  burglar  alarm  or  similar
services, it shall first obtain, and  comply with,  Landlord's  instructions for
their installation.

9. Intentionally Deleted.

10.  Tenant shall not place a load upon any floor of the Premises  which exceeds
the maximum load per square foot which the floor was designed to carry and which
is allowed by law.  Tenant's  business  machines and mechanical  equipment which
cause  noise or  vibration  which may be  transmitted  to the  structure  of the

<PAGE>

Building or to any space therein,  and which is  objectionable to Landlord or to
any  tenants in the  Building,  shall be placed  and  maintained  by Tenant,  at
Tenant's  expense,  on vibration  eliminators  or other  devices  sufficient  to
eliminate noise or vibration.

11.  Tenant  shall  not use or keep  in the  Premises  any  toxic  or  hazardous
materials or any  kerosene,  gasoline or  inflammable  or  combustible  fluid or
material  other than those  limited  quantities  necessary  for the operation or
maintenance  of office  equipment.  Tenant shall not use or permit to be used in
the  Premises  any foul or  noxious  gas or  substance,  or  permit or allow the
Premises  to be  occupied  or used in a manner  offensive  or  objectionable  to
Landlord  or other  occupants  of the  Building  by reason  of  noise,  odors or
vibrations.  No  animal,  except  seeing  eye dogs when in the  company of their
masters, may be brought into or kept in the Building.

12.  Tenant shall not use any method of heating or  air-conditioning  other than
that supplied by Landlord,  unless Tenant  receives the prior written consent of
Landlord.

13.  Tenant shall  cooperate  fully with  Landlord to assure the most  effective
operation of the Building's heating and  air-conditioning and to comply with any
governmental energy-saving rules, laws or regulations of which Tenant has actual
notice.  Tenant shall refrain from attempting to adjust controls other than room
thermostats installed for Tenant's use.

14. All entrance  doors to the  Premises  shall be left locked when the Premises
are not in use, and all doors opening to public  corridors  shall be kept closed
except for normal ingress and egress to and from the Premises.

15.  Landlord  reserves  the  right,  exercisable  without  notice  and  without
liability to Tenant, to change the name and street address of the Building.

16. Landlord reserves the right to prevent access to the Building by closing the
doors or by other  appropriate  action in case of invasion,  mob,  riot,  public
excitement or other commotion.

17.  Tenant shall close and lock the doors of its  Premises,  shut off all water
faucets or other  water  apparatus  and turn off all lights and other  equipment
which is not required to be  continuously  run.  Tenant shall be responsible for
any damage or injuries  sustained by other  tenants or occupants of the Building
or Landlord for noncompliance with this Rule.

18. The toilet rooms, toilets, urinals, wash bowls and other apparatus shall not
be used for any purpose other than that for which they were constructed,  and no
foreign substance of any kind whatsoever shall be placed therein. The expense of
any breakage, stoppage or damage resulting from any violation of this rule shall
be borne by the tenant who, or whose  employees or  invitees,  shall have caused
it.

19. Tenant shall not install any radio or  television  antenna,  loudspeaker  or
other device on the roof or exterior  walls of the  Building,  except as part of
Alterations  approved  by Landlord  pursuant  to Section 9 of the Lease.  Tenant
shall not interfere with radio or television  broadcasting  or reception from or
in the Building or elsewhere.

20. Intentionally Deleted.

21. Tenant shall not install,  maintain or operate upon the Premises any vending
machine (other than vending machines for use by Tenant's  employees) without the
prior written consent of Landlord.

22.  Canvassing,  soliciting  and  distributing  handbills or any other  written
material  and peddling in the  Building  are  prohibited,  and each tenant shall
cooperate to prevent these  activities.

23. Landlord reserves the right to exclude or expel from the Building any person
who, in Landlord's

<PAGE>

judgment, is intoxicated or under the influence of liquor or drugs, or who is in
violation of any of the Rules and Regulations of the Building.

24.  Tenant shall store all its trash and garbage  within its  Premises.  Tenant
shall not place in any trash box or  receptacle  any  material  which  cannot be
disposed of in the ordinary and customary  manner of trash and garbage  disposal
within the Building. All garbage and refuse disposal shall be made in accordance
with directions issued from time to time by Landlord.

25. Use by Tenant of  Underwriters'  Laboratory  approved  equipment for brewing
coffee,  tea, hot chocolate and similar  beverages and microwaving food shall be
permitted,  provided  that  the  equipment  and use is in  accordance  with  all
applicable federal,  state, county and city laws, codes,  ordinances,  rules and
regulations.

26.  Tenant  shall not use the name of the  Building  in  connection  with or in
promoting or  advertising  the business of Tenant,  except as Tenant's  address,
without the written consent of Landlord.

27.  Tenant  shall  comply  with all  safety,  fire  protection  and  evacuation
procedures and regulations  established by Landlord or any governmental  agency.
Tenant shall be responsible for any increased insurance premiums attributable to
Tenant's use of the Premises, Building or Property.

28. Tenant assumes any and all  responsibility  for protecting its Premises from
theft and robbery, which responsibility  includes keeping doors locked and other
means of entry to the Premises closed.

29. Tenant shall not use the Premises,  or suffer or permit  anything to be done
on, in or about the Premises, which may result in an increase to Landlord in the
cost of insurance maintained by Landlord on the Building and Common Areas.

30. Tenant's  requests for assistance will be attended to only upon  appropriate
application to the office of the Building by an authorized individual. Employees
of Landlord  shall not perform any work or do anything  outside of their regular
duties  unless under  special  instructions  from  Landlord,  and no employee of
Landlord  will admit any  person  (Tenant or  otherwise)  to any office  without
specific instructions from Landlord.

31.  Tenant  shall not park its  vehicles in any  parking  areas  designated  by
Landlord  as areas for parking by  visitors  to the  Building or other  reserved
parking  spaces.  Tenant shall not leave vehicles in the Building  parking areas
overnight,  nor park any  vehicles  in the  Building  parking  areas  other than
automobiles,   motorcycles,   motor  driven  or  non-motor  driven  bicycles  or
four-wheeled trucks.  Tenant, its agents,  employees and invitees shall not park
any one (1) vehicle in more than one (1) parking space.

32. The  scheduling  and manner of all Tenant  move-ins and  move-outs  shall be
subject to the discretion  and approval of Landlord,  and move-ins and move-outs
shall take place only after 6:00 p.m.  on  weekdays,  on  weekends,  or at other
times as Landlord  may  designate.  Landlord  shall have the right to approve or
disapprove  the movers or moving  company  employed by Tenant,  and Tenant shall
cause the  movers  to use only the  entry  doors  and  elevators  designated  by
Landlord.  If  Tenant's  movers  damage  the  elevator  or any other part of the
Property, Tenant shall pay to Landlord the amount required to repair the damage.

33. No cooking shall be permitted on the Premises,  except with a microwave oven
or using facilities  constructed as Alterations approved by Landlord pursuant to
Section 9 of the Lease, nor shall the Premises be used for washing clothes,  for
lodging or for any improper, objectionable or immoral purpose.

34.  Tenant shall not use in any space or in the public  halls of the  Building,
any hand trucks except those  equipped with rubber tires and side guards or such
other  material-handling  equipment as Landlord  may  approve.  Tenant shall not
bring any bicycles or other vehicles of any kind into the building.

<PAGE>

35.  Landlord shall have the right to control and operate the public portions of
the Building, and the public facilities,  heating and air conditioning,  as well
as facilities  furnished for the common use of the tenants, in such manner as it
deems best for the benefit of the tenants generally.

36.  Landlord may waive any one or more of these Rules and  Regulations  for the
benefit  of Tenant  or any other  tenant,  but no  waiver by  Landlord  shall be
construed  as a waiver of the Rules  and  Regulations  in favor of Tenant or any
other  tenant,  nor prevent  Landlord  from  thereafter  enforcing the Rules and
Regulations against any or all of the tenants of the Building.

37. These Rules and  Regulations  are in addition to, and shall not be construed
to in any way  modify  or  amend,  in whole or in part,  the  terms,  covenants,
agreements and conditions of any lease of premises in the Building.

38. Landlord  reserves the right to make other  reasonable Rules and Regulations
as, in its  judgment,  may from time to time be needed for safety and  security,
for care and cleanliness of the Building and for the  preservation of good order
therein.  Tenant agrees to abide by all Rules and Regulations hereinabove stated
and any additional rules and regulations which are adopted.

39. Tenant shall be responsible for the observance of all of the foregoing rules
by Tenant's employees, agents, clients, customers, invitees and guests.

<PAGE>

                                    EXHIBIT E

                        TO DEVELOPMENT SERVICES AGREEMENT

                           Tenant Estoppel Certificate
                           ---------------------------

TO:  The  Multi-Employer  Property  Trust,  a trust  organized  under 12  C.F.R.
     Section 9.18 ("Landlord")

                 c/o Kennedy Associates Real Estate Counsel, Inc.
                 2400 Financial Center Building
                 1215 Fourth Avenue
                 Seattle, Washington 98161

THIS IS TO CERTIFY:

         1. That the  undersigned  is the Tenant under that certain  Lease dated
_________________  and, if applicable,  amended on  ___________________,  by and
between The  Multi-Employer  Property  Trust by its trustee  Riggs & Company,  a
division  of  Riggs  Bank  N.A.  ("Landlord"),  and the  undersigned  ("Tenant")
covering those certain premises located as shown on the drawing made part of the
Lease (the "Premises").

         2. That said Lease is in full force and effect and,  except as noted in
paragraph 1 above,  has not been  modified,  changed,  altered or amended in any
respect,  and is the only lease or agreement between the Tenant and the Landlord
affecting the Premises.

         3. To the best of Tenant's  knowledge,  the information set forth below
is true and correct:

            3.1  Square footage of the Premises:________________________________

            3.2 Annual rent as of the commencement of Lease:$___________________

            3.3 Current annual rent (if different than at commencement): $______

            3.4 Commencement date of Lease:_____________________________________

            3.5 Lease termination date:_________________________________________

            3.6 Rent paid to and including:_____________________________________

            3.7 Security deposit: ___________________________________________

            3.8 Prepaid rent for and in amount of:$_____________________________

            3.9 Free Rent Period:_________________________ to __________________

            3.10 Amount of  current  monthly  escrow  payment  obligations  with
                 respect  to  taxes,  insurance,  and  Common  Area  Maintenance
                 charges under the Lease:
                              Taxes:                              $_____________
                              Insurance:                          $_____________
                              Common Area Maintenance Charges:    $_____________

<PAGE>

           3.11  Dates through which Tenant has paid monthly escrow payments and
                 Common Area Maintenance charges:

                              Escrow Payment for Taxes:           $_____________
                              Escrow Payment for Insurance:       $_____________
                              Common Area Maintenance charge:     $_____________

           3.12  Base Amounts  (stops)  established in leases for monthly escrow
                 payments:

                              Base Amount Taxes:                  $_____________
                              Base Amount Insurance:              $_____________
                              Base Amount Maintenance Charge:     $_____________

         4. Tenant now  occupies  the  Premises,  accepts the  Premises in their
current condition subject only to those punch list items listed in Exhibit A, if
any,  and is not aware of any  defect in the  Premises  except as  described  in
Exhibit A, if any.

         5. No rent has been paid in the current  month other than as  disclosed
in  paragraph 3. No free rent or other  concessions,  benefits,  or  inducements
other than as specified  in the Lease have been granted to Tenant or  undertaken
by the Landlord.

         6.  Tenant has not been  granted  any  renewal,  expansion  or purchase
options and has not been granted any rights of first refusal except as disclosed
in writing in the Lease.

         7. Neither Tenant nor to the best of Tenant's knowledge, Landlord is in
breach of the Lease and there has not  occurred  any  event,  act,  omission  or
condition which by notice or lapse of time or both or otherwise,  will result in
any breach by Tenant or to the best of Tenant's  knowledge,  by Landlord.  As of
the date  hereof,  and  except as set forth in the  Lease,  the  undersigned  is
entitled  to no  credit,  offset  or  deduction  in  rent.  Tenant  knows  of no
liabilities or  obligations  of Landlord which have accrued but are  unsatisfied
under the Lease as of the date of this Certificate.

         8. To the best of Tenant's  knowledge,  there are no  actions,  whether
voluntary or otherwise,  pending  against the  undersigned  under the bankruptcy
laws or other laws for the  relief of debtors of the United  States or any state
thereof.

         9.  With the  exception  of this  Lease,  neither  the  Tenant  nor any
affiliate  of the  Tenant  is a  tenant  under  a  lease  or any  other  tenancy
arrangement  (1) with (a) Riggs &  Company,  a division  of Riggs Bank N.A.,  as
trustee of the Multi-Employer Property Trust; (b) Riggs Bank N.A., as trustee of
the Multi-Employer  Property Trust, (c) the  Multi-Employer  Property Trust; (d)
the National Bank of Washington Multi-Employer Property Trust, the previous name
of the Multi-Employer Property Trust; (e) The Riggs National Bank of Washington,
D.C., as trustee of the  Multi-Employer  Property Trust; (f) the Corporate Drive
Corporation as trustee of the Corporate Drive Nominee Realty Trust; (g)

                                      -2-
<PAGE>

Arboretum  Lakes-I,  L.L.C., a Delaware limited liability  company;  (h) Village
Green at Seven Bridges,  L.L.C.; (i) Pine Street  Development,  L.L.C.; (j) MEPT
Realty L.L.C.; (k) MEPT, L.L.C.; (l) Cabrillo  Properties LLC; (m) Valencia LLC;
(n)  Centrepointe  Distribution  Center  LLC;  (o)  Mission  Trails  LLC; or (p)
Northridge  Business  Center LLC; or (2) involving any property in which any one
or more of the  entities  named in clauses  (1) (a) through (e) are known by the
Tenant to have an ownership interest.  [This paragraph will be updated from time
to time.]

         DATED this ___ day of ______________, 19__.

                                     TENANT:
                                     ___________________________________
                                     a _________________________________

                                     By:________________________________
                                           Name: _______________________
                                           Its: ________________________

                                      -3-
<PAGE>

                    EXHIBIT A to Tenant Estoppel Certificate

                                List of Defects
                                ---------------

                                      -4-
<PAGE>

                          CONTINUING GUARANTY OF LEASE

         This  Continuing  Guaranty of Lease,  dated as of October 30, 1998,  is
executed by Certicom Corp., an Ontario  corporation  ("Guarantor"),  in favor of
The  Multi-Employer  Property Trust, a trust  organized under 12 C.F.R.  Section
9.18 ("Landlord").

                                     RECITAL

         As a condition to Landlord's  entering into that certain lease dated on
or about the date hereof (as the same may be amended or otherwise  modified from
time to time,  the "Lease"),  between  Landlord and Certicom  Corp.,  a Delaware
corporation,  as tenant  ("Tenant,"  which term shall include its successors and
assigns),  for  premises  (the  "Premises")  in  the  building  known  as  25801
Industrial Blvd.,  Hayward,  California,  in the business park known as Mt. Eden
Business Park, Landlord is requiring Guarantor to guarantee Tenant's obligations
under the Lease.  Guarantor  will derive  substantial  benefit from the Lease by
virtue of Tenant being a wholly owned subsidiary of Guarantors.

         NOW,  THEREFORE,  as a material  inducement to Landlord's  agreement to
enter into the Lease, Guarantor agrees as follows:

         1.  Guaranty.   Guarantor   hereby   irrevocably  and   unconditionally
guarantees to Landlord the prompt,  full and complete  performance of all of the
obligations  of Tenant  under  the Lease as and when due.  If Tenant at any time
fails to make any payment under the Lease when due or fails to perform or comply
with any covenant,  condition or term of the Lease, Guarantor will, upon written
notice from Landlord and without further demand, pay, perform or comply with the
same in the same manner and to the same extent as is required of Tenant.

         2. Covenants and Acknowledgments.

                  (a)  Guarantor  agrees that,  regardless  of whether  Landlord
gives notice  thereof or obtains the consent of Guarantor  thereto,  Guarantor's
liability hereunder shall not be released,  extinguished or otherwise reduced in
any way by reason of:

                           (i) Any amendment, modification,  renewal, extension,
         substitution  or  replacement  of the  Lease  or any of the  guaranteed
         obligations, in whole or in part;

                           (ii)  Any  acceptance,   enforcement  or  release  by
         Landlord  of any  security  for  the  Lease  or  any of the  guaranteed
         obligations, any addition, substitution or release of any guarantor, or
         any enforcement,  waiver, surrender, impairment, release, compromise or
         settlement  of any  matter  with  respect  to the  Lease  or any of the
         guaranteed obligations or any security therefor;

                           (iii) Any  assignment of this Guaranty in whole or in
         part by  Landlord,  or any  assignment  or  transfer  of the  Lease  by
         Landlord or Tenant, or any sublease by Tenant of the Premises;

                           (iv)  The  invalidity  or   unenforceability  of  any
         provision of the Lease or any of the guaranteed obligations; or

                           (v) Any  failure,  omission  or delay of  Landlord in
         enforcing  the  Lease,  any  of the  guaranteed  obligations,  or  this
         Guaranty,  any refund of payments  received by Landlord with respect to
         any of the guaranteed obligations, or any other action which

                                       1
<PAGE>

         Landlord may take or omit to take in connection with the Lease,  any of
         the guaranteed obligations, or this Guaranty.

                  (b)  Landlord  has  no  duty  to  disclose  to  Guarantor  any
information it receives regarding the financial status of Tenant, whether or not
such  information  indicates that the risk of Guarantor  under this Guaranty has
been or may be increased.  Guarantor assumes full  responsibility  for being and
keeping informed of Tenant's financial condition, Tenant's performance under the
Lease, and Tenant's use and operation of the Premises.

                  (c) Guarantor  hereby  subordinates all its claims for payment
or liens  securing  indebtedness  of Tenant to Guarantor,  if any, to Landlord's
right to receive payment from Tenant of all sums due under the Lease.

                  (d) The  obligations  of  Guarantor  under this  Guaranty  are
primary and are  independent  of the  obligations  of Tenant,  and  Landlord may
directly  enforce its rights under this Guaranty without  proceeding  against or
joining  Tenant or any other  person or entity,  or  applying or  enforcing  any
security for the Lease.

                  (e) Guarantor's obligations hereunder shall not be affected by
any bankruptcy, insolvency, or reorganization of Tenant, by any disaffirmance or
abandonment by a trustee of Tenant, or any termination,  rejection, modification
of the  Lease  or any of the  guaranteed  obligations  in  connection  with  the
bankruptcy,  insolvency  or  reorganization  of Tenant.  If any payments made to
Landlord  by  Tenant  or any other  guarantor  of the  Lease are  deemed to be a
fraudulent,  preferential  or  voidable  transfer,  then  Guarantor's  liability
hereunder  shall  automatically  be revived,  reinstated  and restored as to the
amount of any such transfer plus all costs and expenses  (including  court costs
and attorneys' fees) of Landlord related thereto.

         3.  Waivers.  Guarantor  waives (a) any right to the  benefit of, or to
direct the  application  of, any  security  held by  Landlord,  (b) any right to
require  Landlord to proceed  against  Tenant or any other  person or entity for
enforcement of the Lease or the guaranteed obligations,  (c) any defense arising
out of any alteration of the Lease or the guaranteed obligations,  (d) any right
of  subrogation  to any  rights of  Landlord,  and any  right of  reimbursement,
indemnity or contribution against any person or entity with direct or contingent
liability for any of the guaranteed  obligations,  (e) any defense to Landlord's
recovery of any  deficiency  after  Landlord has  exercised any right or remedy,
even if such  exercise  results  in any  impairment  of  Guarantor's  rights  of
reimbursement  or subrogation or any other rights of Guarantor  against  Tenant,
(f) any defense  arising out of the absence,  impairment or loss of any right of
reimbursement  or  subrogation  or other  right or remedy of  Guarantor  against
Tenant or any security  held by Landlord,  (g) any defense  arising by reason of
any legal  disability  or other  defense  of Tenant to the  enforcement  of this
Guaranty,  or the  cessation or  reduction  of the  liability of Tenant from any
cause  whatsoever  other than full  payment,  performance  and  discharge of the
obligations  under the Lease,  (h) notice of  acceptance of this  Guaranty,  (i)
notice  of  Tenant's  default  in  the  payment  or  performance  of  any of the
guaranteed obligations,  and (j) presentment,  demand, protest and notice of any
other kind.

         4. Miscellaneous.

                  (a) This Guaranty  shall inure to the benefit of any person or
entity who at any time may be  entitled  to the  benefits  of, or  obligated  to
perform the duties of,  Landlord under the Lease,  and shall be binding upon the
heirs, administrators, successors and assigns of Guarantor.

                  (b) Guarantor  agrees to pay on demand all costs and expenses,
including  court  costs and  attorneys'  fees,  incurred  or paid by Landlord in
enforcing  this Guaranty or  collecting  any sums due  hereunder,  together with
interest on all such amounts at the maximum interest rate allowed by law.

                                       2
<PAGE>

                  (c) This Guaranty may not be changed orally, and no obligation
of Guarantor can be released or waived except by a writing signed by Landlord.

                  (d)  If any  term  or  provision  of  this  Guaranty  is  ever
determined  to be illegal or  unenforceable,  all other terms and  provisions of
this Guaranty  shall remain  effective  and  enforceable  to the fullest  extent
permitted by law.

                  (e) This Guaranty and the rights and  obligations of Guarantor
and  Landlord  under  this  Guaranty  shall  be  governed  by and  construed  in
accordance with the laws of the State of California, and the venue of any action
or proceeding under this Guaranty shall be the City and County of San Francisco,
California.  Guarantor  hereby submits to personal  jurisdiction in the State of
California for the  enforcement  of this  Guaranty,  waives any and all personal
rights  under the laws of the  State of  California  to  object to  jurisdiction
within that state for the purposes of any action or  proceeding  to enforce this
Guaranty,  and  agrees  that  service  of  process  may be  made,  and  personal
jurisdiction  over Guarantor  obtained,  by service of process upon Guarantor at
the  address  set  forth  below  or by any  other  means of  obtaining  personal
jurisdiction and perfecting  service of process as now or hereafter  provided by
the laws of the State of California.

                  (f) IF ANY ACTION OR PROCEEDING BETWEEN LANDLORD AND GUARANTOR
TO ENFORCE THE  PROVISIONS  OF THIS  GUARANTY  PROCEEDS TO TRIAL,  LANDLORD  AND
GUARANTOR HEREBY WAIVE THEIR RESPECTIVE RIGHTS TO A JURY IN SUCH TRIAL. Landlord
and Guarantor agree that this paragraph  constitutes a written consent to waiver
of trial by jury  within  the  meaning  of  California  Code of Civil  Procedure
Section  631(a)(2),  and Guarantor does hereby authorize and empower Landlord to
file this paragraph and or Guaranty, as required, with the clerk or judge of any
court of competent jurisdiction as a written consent to waiver of jury trial.

                  (g) Any notices to be sent by either party hereto to the other
party shall be in writing and delivered personally,  sent by reputable overnight
or same-day  courier,  or sent by United States  certified or  registered  mail,
postage prepaid, and addressed,  if the notice is from Guarantor to Landlord, to
Landlord, c/o Simeon Commercial  Properties,  655 Montgomery Street; Suite 1190,
San  Francisco,  California  94111,  and if  the  notice  is  from  Landlord  to
Guarantor,  to Guarantor at Certicom Corp.,  200 Matheson Blvd. W,  Mississauga,
Ontario,  Canada L5R 3L7. Either party may change the address to which notice to
such party shall be sent  hereunder by providing  the other party with notice of
such address in accordance with the provisions of this paragraph.

                  (h) If this  Guaranty  is signed by more than one  party,  the
term "Guarantor"  shall mean each of the parties signing as Guarantor,  and each
obligation under this Guaranty shall be their joint and several obligation.

         IN WITNESS  WHEREOF,  this  Guaranty  has been  executed by  Guarantor,
effective as of the date first set forth above.

                                    Guarantor

                                    CERTICOM CORP., an Ontario corporation

                                    By: /s/ B. MacInnis
                                        --------------------------

                                      Name: /s/ Bruce MacInnis
                                            ----------------------

                                      Title: Vice President + CFO
                                             ---------------------

                                       3
<PAGE>

     SIMEON
[GRAPHIC OMITTED]

655 Montgomery Street
    Suite 1190
 San Francisco, CA
    94111-2630

 ph: 415/986-2002
 fax: 415/986-2130

May 21, 1999

Mr. Bruce MacInnis
Certicom Corp.
200 Matheson Blvd., West, Suite 103
Mississauga, Onatrio - CANADA

RE: Mt. Eden Business Park-Operating Expenses

Dear Bruce:

In  accordance  with  Paragraph 5 of your lease dated  October 30, 1998 enclosed
please  find  Invoice  #05-09  which  represents  the 1999  Estimated  Operating
Expenses for your offices at the above referenced  property,  effective March 1,
1999.

The total due June 1, 1999 is outlined below:

               Invoice #05-09                $21,536.00
               Base Rent                     $53,568.75
               Monthly Operating Expenses    $ 7,718.67
                                             ----------
               Total Due June 1, 1999        $82,823.42

The revised monthly rent due July 1, 1999 and each month thereafter shall be:

               Base Rent                     $53,568.75
               Monthly Operating Expenses    $ 7,718.67
                                             ----------
               Total                         $61,287.42

Please remit all payments to the address below:

                                Riggs Bank - MEPT
                             Mt. Eden Business Park
                                 Dept. 05899-05
                                 P.O. Box 39000
                           San Francisco CA 94139-5899

Please  feel free to  contact me if you have any  questions.  Thank you for your
patience in receiving this document.

Sincerely,
SIMEON Commercial Properties

/s/ Barbara Mondani

Barbara Mondani
Property Manager

Enclosures

cc: Starla Ackley

  A Family
of Real Estate
  Companies

<PAGE>

                            FIRST AMENDMENT TO LEASE

                   THIS FIRST AMENDMENT TO LEASE (this "Amendment"),  is made as
of the 17th day of November,  1998, by and between THE  MULTI-EMPLOYER  PROPERTY
TRUST, A TRUST ORGANIZED UNDER 12 C.F.R. SECTION 9.18 ("Landlord"), and CERTICOM
CORP., a Delaware corporation ("Tenant").

                   WHEREAS,  Landlord and Tenant entered into that certain lease
dated  October 30, 1998 (the  "Lease"),  with respect to certain  premises  (the
"Premises")  located at 25801  Industrial Blvd. in the Mt. Eden Business Park in
Hayward, California;

                   WHEREAS,  the lease  incorrectly  sets forth the agreement of
Landlord and Tenant regarding Base Rent  adjustments,  and the parties desire to
amend  the  Lease to  correct  such  error.  Unless  otherwise  defined  herein,
capitalized terms are used herein as defined in the Lease.

                   NOW,  THEREFORE,  the  parties  hereto  do  hereby  agree  as
follows:

                   1. Base Rent Adjustment.  Section 4.b. of the Lease is hereby
amended to read in its entirety as follows:

"b. Base Rent Adjustment.  Commencing on the first day of the 37th full calendar
month of the Term,  the Base Rent shall  increase to $58,536.00  per month,  and
shall be payable in such amount  through the end of the 72nd full calendar month
of the Term.  Commencing on the first day of the 73rd full calendar month of the
Term, the Base Rent shall increase to $63,964.00 per month, and shall be payable
in such amount through the Expiration Date."

                   2. Ratification.  Except as amended hereby, the Lease remains
unmodified and in full force and effect.

                   3. Entire Understanding. This Amendment represents the entire
understanding  between of the parties  concerning the subject matter hereof, and
there are no understandings or agreements  between them relating to the Lease or
the leased  premises not set forth in writing and signed by the parties  hereto.
No party hereto has relied upon any  representation,  warranty or  understanding
not set forth  herein,  either oral or written,  as an  inducement to enter into
this Amendment.

                   4. Counterparts. This Amendment may be executed in any number
of  counterparts,  each of which shall be deemed an  original,  and all of which
together shall constitute one and the same instrument.

                                        1

<PAGE>

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

Landlord:                                         Tenant:

THE MULTI-EMPLOYER                                CERTICOM CORP.,
PROPERTY TRUST, A TRUST                           a Delaware corporation
ORGANIZED UNDER 12 C.F.R.
SECTION 9.18, by its trustee
Riggs & Company, a division of                    By:  /s/ Philip C. Deck
Riggs Bank N.A.                                        -------------------------

                                                  Its: Chairman & CEO
                                                       -------------------------

By:       Illegible                               By:  /s/ Bruce MacInnis
     -------------------------                         -------------------------

Its:      Illegible                               Its: VP Finance & CFO
     -------------------------                         -------------------------

                   The  undersigned,  as Guarantor of the Lease pursuant to that
certain  Continuing  Guaranty  of  Lease  dated  as of  October  30,  1998  (the
"Guaranty"),  hereby  consents to the  foregoing  Amendment  and agrees that the
Guaranty  shall remain in full force and effect and shall apply to the foregoing
Amendment and to the Lease as amended thereby.

                                                  Guarantor

                                                  CERTICOM CORP., an Ontario
                                                  corporation

                                                  By: /s/ Bruce MacInnis
                                                      --------------------------

                                                  Name: Bruce MacInnis
                                                        ------------------------

                                                  Title: VP Finance & CFO
                                                         -----------------------

                                        2

<PAGE>

                            SECOND AMENDMENT TO LEASE

                   THIS SECOND AMENDMENT TO LEASE (this "Amendment"), is made as
of the 15 day of March, 2000, by and between THE MULTI-EMPLOYER  PROPERTY TRUST,
A TRUST ORGANIZED UNDER 12 C.F.R. SECTION 9.18 ("Landlord"), and CERTICOM CORP.,
a Delaware corporation ("Tenant").

                   WHEREAS,  Landlord and Tenant entered into that certain lease
dated  October  30,  1998,  as amended by First  Amendment  to Lease dated as of
November 17, 1998 (as so amended, the "Lease"), with respect to certain premises
(the  "Original  Premises")  located at 25801  Industrial  Blvd. in the Mt. Eden
Business Park in Hayward, California (the "Business Park");

                   WHEREAS,  the  parties  desire  to  amend  the  Lease  to add
additional space in the Business Park to the premises demised  thereunder and to
make certain  changes to the Lease in  connection  therewith.  Unless  otherwise
defined herein, capitalized terms are used herein as defined in the Lease.

                   NOW,  THEREFORE,  the  parties  hereto  do  hereby  agree  as
follows:

                   1. Additional Premises.

                   a.  Effective as of April 1, 2000 (the  "Additional  Premises
Commencement  Date"),  the  Additional  Premises  shall be added to the premises
demised to Tenant under the Lease.  The term of the Lease,  as applicable to the
Additional  Premises,  shall  expire  on  the  date  (the  "Additional  Premises
Expiration  Date")  that is seven (7) years from the  Additional  Premises  Rent
Commencement Date (as defined in Paragraph 3 below).  The "Additional  Premises"
shall mean that portion of the  building  known as 25821  Industrial  Boulevard,
located in the Business Park, as shown on Exhibit A attached hereto. The parties
hereby  stipulate  that for all purposes of this  Amendment  and the Lease,  the
Additional  Premises  consist of 68,182 rentable square feet. From and after the
Additional  Premises  Commencement  Date, the term  "Premises" used in the Lease
shall be deemed to refer to the Original  Premises and the Additional  Premises,
and all of the terms,  covenants and  conditions of the Lease  applicable to the
Original  Premises  shall be applicable to the  Additional  Premises,  except as
hereinafter  set forth or to the extent in conflict with the  provisions of this
Amendment.

                   b. The  Additional  Premises  shall be delivered to Tenant in
their then "as-is" condition, and Landlord shall not have any obligation to make
or, except as provided in Paragraph 2 below, pay for any alterations,  additions
or improvements to prepare the Additional Premises for Tenant's occupancy.

                   c. If, for any reason,  Landlord cannot deliver possession of
the Additional Premises to Tenant on the Additional Premises  Commencement Date,
(i) Tenant's obligations hereunder with respect to the Additional Premises shall
not commence,  and the Additional Premises Commencement Date shall not be deemed
to have occurred,  until  possession of the Additional  Premises is delivered to
Tenant,  (ii) the failure shall not affect the validity of this Amendment or the
Lease, or, except as provided in clause (i), the obligations of Tenant

                                       1

<PAGE>

hereunder or under the Lease,  (ii) such  failure  shall not serve to extend the
Additional  Premises Expiration Date, and (iii) Landlord shall not be subject to
any liability.

                   2.  Tenant  Improvements.   Any  alterations,   additions  or
improvements which Tenant desires to make to the Additional  Premises to prepare
the same for Tenant's  initial  occupancy (the "Tenant  Improvements")  shall be
performed in accordance  with, and be subject to all provisions of, Section 9 of
the Lease.  Landlord shall contribute toward the cost of the construction of the
Tenant Improvements an amount not to exceed $681,820.00 (which is the product of
$10.00 times the  stipulated  number of rentable  square feet of the  Additional
Premises) ("Landlord's Contribution"). The following provisions shall govern the
payment of Landlord's Contribution:

                   A.  Excess  Cost:  Share  of  Costs.  If the  total  cost  of
construction of the Tenant Improvements  (including the Alteration Fee described
in Section 9 of the Lease and the City of Hayward Interim Supplemental  Building
Construction  and  Improvement  Tax) exceeds the funds  available  therefor from
Landlord's  Contribution,  then Tenant  shall pay all such  excess (the  "Excess
Cost").  Based on the estimated cost (the "Estimated Costs") of the construction
of the Tenant Improvements,  the prorata share of the Estimated Costs payable by
Landlord and Tenant shall be  determined  and an  appropriate  percentage  share
established  for each (a "Share of Costs").  Tenant and Landlord  shall fund the
cost of such work as the same is performed,  in accordance with their respective
Share of Costs for such work. At such time as Landlord's  Contribution  has been
entirely  disbursed,  Tenant shall pay the remaming  Excess Cost, if any,  which
payments shall be made in installments  as  construction  progresses in the same
manner as Tenant's  payments of Tenant's  Share of Costs were paid.  At the time
Landlord  makes any  disbursement  of Landlord's  Contribution,  Landlord  shall
retain from Landlord's Contribution, as a partial payment of the Alteration Fee,
a proportionate  amount of the Alteration Fee based upon  Landlord's  reasonable
estimate of the amount  required to be withheld from such  disbursement in order
to  ensure  that the  entire  Alteration  Fee is  retained  over the  course  of
construction  on a prorata basis.  At such time as Landlord's  Contribution  has
been entirely  disbursed,  if the entire Alteration Fee has not yet been paid to
Landlord, Tenant shall pay to Landlord a prorata portion of each payment made by
Tenant on account of the Tenant Improvements in order to ensure that the balance
of the Alteration Fee is paid to Landlord over the course of  construction  on a
prorata  basis.  Notwithstanding  anything to the contrary in this  Paragraph 2,
Landlord's  Contribution  shall be available  for  disbursement  pursuant to the
terms hereof only during the calendar year 2000. Accordingly,  if any portion of
Landlord's  Contribution is not utilized prior to December 31, 2000, such unused
portion shall be forfeited by Tenant.

                   B. Certain Costs. Portions of Landlord's Contribution may, at
Tenant's election,  be applied toward Tenant's  architectural fees in connection
with the design and construction of the Tenant Improvements;  provided, however,
that the portion of Landlord's  Contribution applied to such fees may not exceed
One Dollar ($1.00) per rentable  square foot of the Additional  Premises and any
excess shall be paid directly by Tenant to Landlord from Tenant's own funds.  In
no event may any  portions of  Landlord's  Contribution  be applied  towards the
costs of Tenant's engineering fees (if any), trade fixtures,  personal property,
equipment or furniture, or towards rent due under this Lease.

                   C.  Entire  Additional   Premises  to  be  Improved.   Tenant
acknowledges  that  Landlord's  Contribution  is to be  applied  to  the  Tenant
Improvements  (and the costs  permitted under Paragraph 2.B. above) covering the
entire Additional Premises. If Tenant does not

                                       2

<PAGE>

improve the entire Additional  Premises,  then,  without limitation of any other
rights or remedies  of  Landlord  hereunder,  Landlord's  Contribution  shall be
adjusted  on a prorata per  rentable  square foot basis to reflect the number of
rentable square feet actually being improved.

                   3. Base  Rent.  Commencing  as of the date  (the  "Additional
Premises Rent Commencement  Date") that is the earlier of (i) one-hundred twenty
(120) days after the  Additional  Premises  Commencement  Date, or (ii) Tenant's
occupancy of the Additional  Premises or any portion  thereof for the conduct of
business,  and  thereafter on the first day of each calendar  month of the Term,
Tenant shall pay to Landlord (or other entity  designated by Landlord) Base Rent
for the Additional  Premises,  in advance, at Landlord's address for notices (as
set forth in the Basic Lease  Information in the Lease) or at such other address
as Landlord may  designate.  The initial Base Rent for the  Additional  Premises
shall be Sixty-One  Thousand  Three  Hundred  Sixty-Four  Dollars  ($61,364.00).
Effective  as of  each  annual  anniversary  of  the  Additional  Premises  Rent
Commencement  Date, the Base Rent payable by Tenant for the Additional  Premises
shall  increase to  one-hundred  three  percent  (103%) of the Base Rent then in
effect for the Additional Premises.  From and after the Additional Premises Rent
Commencement Date, the term "Base Rent" as used in the Lease shall mean the Base
Rent  payable  for the  Original  Premises  and the Base  Rent  payable  for the
Additional  Premises,  collectively.  The Base Rent for the Additional  Premises
shall be payable by Tenant in  addition  to the Base Rent  payable by Tenant for
the Original Premises, as set for the in the Lease.

                   4.  Operating  Expenses.  Commencing  as  of  the  Additional
Premises Rent Commencement Date, and continuing thereafter during the balance of
the Term,  the  provisions  of Section 5 of the Lease shall be applicable to the
Additional  Premises.  As so  applied  to  the  Additional  Premises,  the  term
"Tenant's  Percentage Share" shall mean seventy-five percent (75%), and the term
"Building" shall mean the building in which the Additional Premises are located.
The Operating Expenses for the Additional Premises shall be payable by Tenant in
addition to the Operating  Expenses payable by Tenant for the Original Premises,
as set forth in the Lease.

                   5. Security Deposit: Letter of Credit.

                   a. Concurrently with Tenant's  execution and delivery of this
Amendment to Landlord,  Tenant shall increase the Security Deposit  delivered to
Landlord  pursuant to Section 17 of the Lease to the amount of One Hundred Fifty
Thousand Dollars ($150,000.00),  and the term "Security Deposit", as used in the
Lease, shall thereafter refer to the Security Deposit in such amount.

                   b.  In  addition  to the  increase  in the  Security  Deposit
required  pursuant to  Paragraph 5 .a.  above,  and in addition to the Letter of
Credit  previously  delivered  by Tenant  pursuant  to the Lease (the  "Original
Letter of Credit"),  on or prior to the Additional  Premises  Commencement Date,
Tenant  shall  deliver an  additional  Letter of Credit to  Landlord  as further
security for Tenant's  performance of all of Tenant's  covenants and obligations
under the Lease.  Such additional  Letter of Credit (the  "Additional  Letter of
Credit"),  and any  proceeds  therefrom,  shall be  subject to all of the terms,
covenants and  conditions  applicable to the Original  Letter of Credit,  as set
forth in Section 17 of the Lease,  except that the  Additional  Letter of Credit
shall be in the  original  amount of One Million Two  Hundred  Thousand  Dollars
($1,200,000.00) during the period from the Additional Premises Commencement Date
through  the  third  annual   anniversary  of  the   Additional   Premises  Rent
Commencement Date, and reducing in amount on

                                       3

<PAGE>

the third annual  anniversary of the Additional  Premises Rent Commencement Date
and on each  subsequent  annual  anniversary  of the  Additional  Premises  Rent
Commencement  Date  by  twenty  percent  (20%)  of the  original  amount  of the
Additional  Letter  of  Credit;  provided,  however,  that  if on the  date  the
Additional  Letter of Credit amount would otherwise reduce, an Event of Default,
or default  that with notice or the passage of time or both could mature into an
Event of Default,  shall have occurred and be continuing,  the Additional Letter
of Credit amount shall not reduce on such date and shall not  thereafter  reduce
until the later of the next  scheduled  reduction date or the date such Event of
Default or default shall have been cured.  Where reference is made in Section 17
of the Lease to the Term of the Lease (for  purposes of  determining  the period
during which the Original  Letter of Credit or the Additional  Letter of Credit,
as applicable, must be maintained in effect), as respects the Original Letter of
Credit such reference  shall mean the Term of the Lease as respects the Original
Premises,  and as respects the Additional  Letter of Credit such reference shall
mean the Term of the Lease as respects the Additional Premises.

                   6.  Lease  Term.  Effective  as of  the  Additional  Premises
Commencement  Date, the expiration  date of the term of the Lease, as applicable
to the Original Premises, shall be deemed extended from February 28, 2006 (which
the parties  acknowledge  to be the current  expiration  date of the term of the
Lease as respects the Original Premises) to the Additional  Premises  Expiration
Date. All of the terms, covenants and conditions of the Lease shall apply during
such extension period (the "Extension Period"),  except the Base Rent payable by
Tenant  for the  Original  Premises  shall be the  "fair  market  rent"  for the
Original  Premises for the Extension  Period.  "Fair market rent" shall have the
meaning  given in Section 40 of the Lease,  with all  references to the "renewal
period" being deemed  references  to the  "Extension  Period".  The "rent floor"
specified in Section  40.b.  of the Lease shall be fully  applicable as respects
the Extension Period.

                   7. Renewal Option. Pursuant to Section 40 of the Lease, as of
the date of this Amendment  Tenant has the option to renew the Lease for one (1)
additional  term of five (5) years.  In the event that Tenant validly  exercises
its  option  to renew  the Lease for such  additional  five (5) year  term,  the
parties hereby agree that such exercise shall apply to the entire  premises then
demised hereunder (i.e. both the Original Premises and the Additional Premises),
and such option may not be exercised  as to less than all of the  premises  then
demised  hereunder.  The "rent floor"  specified in Section  40.b.  of the Lease
shall be determined,  for purposes of such renewal,  by reference to the average
Base Rent, per rentable  square foot,  payable by Tenant for all of the premises
then demised hereunder.

                   8. Building  Definition.  The  definition  of the  "Building"
contained in the Lease is hereby modified to mean,  collectively,  the buildings
in which the Original Premises and the Additional  Premises are located,  unless
the context expressly requires  otherwise.  As used in Section 11 and Section 12
of the Lease,  the term "Building" means only the building in which the Original
Premises or Additional  Premises are located which has been damaged or destroyed
or the subject of the taking by eminent  domain (or conveyance in lieu thereof),
as applicable, and notwithstanding anything to the contrary contained in Section
11 or Section 12 of the Lease,  where  Landlord or Tenant is granted in any such
Section  a right or  option  to  terminate  this  Lease by  reason  of damage or
destruction  to, or a taking by eminent  domain (or conveyance in lieu thereof),
of the  Premises  or the  Building,  such  right or  option  shall  only  permit
termination  of the Lease as to the space  demised  thereunder  in the  building
which has been damaged or  destroyed or subject to the taking by eminent  domain
(or conveyance in lieu thereof).

                                       4

<PAGE>

                   9.  Ratification. Except as amended hereby, the Lease remains
unmodified and in full force and effect.

                   10. Brokers. Each party hereto represents and warrants to the
other party  hereto that it has dealt with no broker or finder who can  properly
claim a commission,  fee or other  compensation  by reason of this  Amendment or
Tenant's lease of the  Additional  Premises,  except that Landlord  acknowledges
that it has dealt with Colliers Parish International, Inc. ("Landlord's Broker")
in connection with this Amendment.  Each party hereto shall  indemnify,  protect
and hold  harmless  the other  party  hereto  from and against any and all loss,
cost,  damage,  liability  and  expense  (including  attorneys'  fees and costs)
arising out of any breach or alleged breach of its foregoing  representation and
warranty.  In addition,  Landlord  shall pay any  commission  due to  Landlord's
Broker  by  reason  of  this  Amendment  pursuant  to the  terms  of a  separate
agreement.

                   11.  Entire  Understanding.  This  Amendment  represents  the
entire  understanding  between of the  parties  concerning  the  subject  matter
hereof,  and there are no understandings or agreements  between them relating to
the Lease or the  leased  premises  not set forth in  writing  and signed by the
parties hereto. No party hereto has relied upon any representation,  warranty or
understanding not set forth herein,  either oral or written, as an inducement to
enter into this Amendment.

                   12.  Counterparts.  This  Amendment  may be  executed  in any
number of  counterparts,  each of which shall be deemed an original,  and all of
which together shall constitute one and the same instrument.

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

Landlord:                                       Tenant:

THE MULTI-EMPLOYER                              CERTICOM CORP.,
PROPERTY TRUST, A TRUST                         a Delaware corporation
ORGANIZED UNDER 12 C.F.R.
SECTION 9.18, by its trustee
Riggs & Company, a division of                  By: /s/ Richard P. Dalmazzi
Riggs Bank N.A.                                     ----------------------------
                                                        Richard P. Dalmazzi
                                                        President and CEO

By:  /s/ Name Illegible                         By: /s/ Richard D. Brounstein
     ----------------------------                   ----------------------------
                                                        Richard D. Brounstein
Its: Managing Director                                  Chief Financial Officer
     ----------------------------

                                        5

<PAGE>

                   The  undersigned,  as Guarantor of the Lease pursuant to that
certain  Continuing  Guaranty  of  Lease  dated  as of  October  30,  1998  (the
"Guaranty"),  hereby  consents to the  foregoing  Amendment  and agrees that the
Guaranty  shall remain in full force and effect and shall apply to the foregoing
Amendment and to the Lease as amended  thereby.  The undersigned  represents and
warrants  to  Landlord  that it is the  successor  entity  to the  entity  which
originally  executed the Guaranty and the confirmation of the Guaranty contained
at the end of the First Amendment to the Lease.

                                      Guarantor:

                                      CERTICOM CORP a Yukon corporation

                                      By: /s/ Richard P. Dalmazzi
                                          ----------------------------
                                              Richard P. Dalmazzi
                                              President and CEO

                                      By: /s/ Richard D. Brounstein
                                          ----------------------------
                                              Richard D. Brounstein
                                              Chief Financial Officer

                                       6LEASE

THIS LEASE made as of the 29th day of March, 1999
PURSUANT TO THE SHORT FORMS OF LEASES ACT

BETWEEN:

                      AIRPORT CORPORATE CENTRE OFFICE PARK INC.

                      the "Landlord")
                                                               OF THE FIRST PART
AND:

                      CERTICOM CORP.

                      (the "Tenant")

                                                              OF THE SECOND PART

Articles.  For  convenience  of  reference  this Lease has been divided into the
following Articles:

         Article I     - Definitions
         Article II    - Lease Term and Payments
         Article III   - Landlord and Tenant Covenants
         Article IV    - Repair and Damage
         Article V     - Taxes and Operating Costs
         Article VI    - Utilities and Additional Services
         Article VII   - Assigning and Subletting
         Article VIII  - Fixtures and Improvements
         Article IX    - Insurance and Liability
         Article X     - Subordination, Attornment and Certificates
         Article XI    - Events of Default and Remedies
         Article XII   - Miscellaneous
         Article XIII  - Other Provisions

List of Schedules. The following schedules form an integral part of this Lease:

         Schedule "A"   - Legal Description of Lands
         Schedule "B"  - Leased Premises
         Schedule "C"  - Rules and Regulations
         Schedule "D"  - Building Specifications
         Schedule "E"  - Development Schedule
         Schedule "F"  - Site Plan
         Schedule "G"  - Exclusions from Operating Costs

ARTICLE 1.00 - Definitions

1.1    Definitions.  In this Lease the  following  defined  terms shall have the
       meanings set forth below.

       "Additional  Rent" means  Operating  Costs under Section 5.5, Taxes under
       5.3,  Electricity under 6.2, and insurance under Article IX and all other
       charges,  costs and expenses  required to be paid by the Tenant under the
       terms of this  Lease  (other  than Base  Rental)  whether  payable to the
       Landlord or not.

       "Additional  Services" means the services and supervision supplied by the
       Landlord to the Leased  Premises and Common Area  Facilities and referred
       to

<PAGE>

                                       -2-

       herein or in any other  provision  hereof as Additional  Services and any
       other  services  which  from time to time the  Landlord  supplies  to the
       Tenant  at  the  Tenant's  written  request  or  as  the  Landlord  deems
       necessary, acting reasonably, and which are additional to the janitor and
       cleaning and other  services  typically  supplied in a first class office
       building,  supervision  in  connection  with the making of any repairs or
       alterations by the Tenant  affecting the Base Building,  building systems
       or Leasehold Improvements.

       "Attic  Stock"  means spare fan,  pump and  cooling  tower  motors,  base
       Building light fixtures, fuses, etc.

       "Base Rental"  means the Base Rental  payable by the Tenant in accordance
       with Section 2.3.

       "Building" means the building municipally known as 5520 explorer Drive on
       plan attached  hereto as Schedule "F", and fronting on Explorer  Drive in
       the City of Mississauga, Regional Municipality of Peel.

       "Capital  Tax" is an amount  presently or hereafter  imposed from time to
       time  pursuant to Part III of the  Corporations  Tax Act  (Ontario)  (the
       "Act")  upon the  Landlord  or the  owner of the  Building  and Lands and
       payable by the  Landlord on account of its  interest in the  Building and
       the Lands or any part thereof,  or its interest in or capital employed in
       the Building and the Lands, as the case may be.

       "Commencement  Date"  means  December  15th, 1999, subject to Section 2.3
       hereof.

       "Common   Area   Facilities"   means   all   facilities,    improvements,
       installations,  utilities  and  equipment  located in the Building or the
       Lands immediately surrounding the Building.

       "Common Areas" means those areas,  facilities,  utilities,  improvements,
       equipment and  installations  comprising the Lands and Building and which
       are not leased or designated  for lease to tenants but are provided to be
       used in common by (or by the sublessees,  agents, employees, customers or
       licensees of) the Landlord, the Tenant, and other tenants of the Building
       and other buildings on the Lands, whether or not the same are open to the
       general public or a specific tenant of the Building, and include, but are
       not limited to,  parking areas and all  vestibules  for and entrances and
       exits  thereto;  driveways,  truckways and related  areas;  corridors and
       underground   or  above  ground   tunnels  or   passageways;   stairways,
       escalators,  ramps, and elevators and other transportation  equipment and
       systems;  tenant, common and public washrooms;  telephone,  meter, valve,
       mechanical,  mail,  storage,  service and janitor rooms; fire prevention,
       security and  communication  systems,  any fixtures,  chattels,  systems,
       decor,  signs,  facilities,  or landscaping  and planted areas  contained
       therein or maintained or used in connection therewith.

       "Cost  of  Additional  Services"  shall  mean in the  case of  Additional
       Services  provided by the Landlord a reasonable  charge made  therefor by
       the Landlord  which shall not exceed the cost of obtaining  such services
       from  independent  contractors  and in the  case of  Additional  Services
       provided  by  independent   contractors  the  Landlord's  total  cost  of
       providing  Additional  Services to the Tenant including the proportionate
       cost of all direct labour (including salaries, wages and fringe benefits)
       and materials and other direct expenses incurred, the cost of supervision
       without  duplication  or profit and other expenses  reasonably  allocated
       thereto.

       "Insured  Damage"  means that part of any damage  occurring to the Leased
       Premises of which the entire cost of repair is actually  recovered by the
       Landlord (less any deductibles payable in respect thereof) under a policy
       of  insurance  in  respect  of fire and  other  perils  from time to time
       effected by the Landlord, or for

<PAGE>

                                      -3-

       which the Landlord has  self-insured  under Section 9.1 herein,  less any
       deductibles payable in respect thereof.

       "Land" means those lands described in Schedule "A" attached hereto.

       "Lease"  means this Lease  between the Landlord  and the Tenant,  and all
       amendments hereto.

       "Leasehold Improvements" means all fixtures, improvements, installations,
       alterations and additions from time to time made, erected or installed by
       or on  behalf of the  Tenant  or by or on  behalf  of any other  previous
       occupant  in the  Leased  Premises  (including  the  Landlord)  with  the
       exception of trade fixtures,  furniture and equipment, (not of the nature
       of  fixtures),  modular  office  furniture  systems,  improvements  of  a
       cosmetic nature such as rugs (but not  broadloom),  decorations and other
       improvements   moveable   without  the  use  of  tools,   but   Leasehold
       Improvements  include all office partitions  however affixed and includes
       wall-to-wall  and other  carpeting  with the exception of such  carpeting
       where laid over vinyl tile or other  finished  floor and affixed so as to
       be readily removable without damage.

       "Leased Premises" means approximately 25,000 square feet of Rentable Area
       on the  fourth  floor of the  Building  as  outlined  in red on the plans
       attached as Schedule "B", in accordance with current BOMA standards.

       "Normal  Business Hours" means the hours of 7:00 a.m. to 7:00 p.m. Monday
       to Friday, except public holidays.

       "Operating Costs" means the total, without duplication, of all reasonable
       expenses,  reasonable  costs,  and  reasonable  outlays  incurred  in the
       complete  maintenance,  repair and  operation  of the Building and Common
       Area Facilities, whether incurred by or on behalf of the Landlord.

       (i)    Operating Costs shall include  without  limiting the generality of
              the  foregoing  but without  duplication  (but  subject to certain
              deductions as hereinafter  provided),  for the following expenses,
              costs and outlays, but only to the extent that same are reasonable
              having regard to the nature of the project:  the cost of providing
              complete  cleaning and janitorial  services,  the cost of building
              supplies used in the  maintenance  of the  Building,  Attic Stock,
              supervisory   (if  any)   and   maintenance   services,   exterior
              landscaping,  snow  removal,  garbage  and  waste  collection  and
              disposal,  rental of equipment and signs,  janitorial  services to
              the Common Areas of the Building, the cost of operating elevators,
              the cost of heating,  cooling and  ventilating all space including
              both rentable and  non-rentable  areas,  the cost of providing hot
              and  cold  water,   electricity  (including  lighting),   and  the
              replacement of electric  light bulb tubes,  starters and ballasts,
              telephone  and other  utilities  and services to both rentable and
              non-rentable  areas, the cost of all repairs  including repairs to
              the Building or services in the Building or Common Area Facilities
              including  elevators,  depreciation  on the central  HVAC  systems
              distribution plant and associated  equipment,  depreciation on all
              fixtures,  equipment and facilities requiring periodic maintenance
              or  substantial  replacement,  the cost of  window  cleaning,  and
              providing  security  (if  any),  the  cost  of all  insurance  for
              liability or fire or other casualties  referred to in Article 9.1,
              accounting  costs  incurred in  connection  with  maintenance  and
              operation  including  computations  required for the imposition of
              charges to tenants and audit  charges  required to be incurred for
              the conclusive  determination of any costs hereunder,  legal fees,
              the amount of all salaries  (only to the extent that such salaries
              or a proportion thereof,  relate directly to the Building),  wages
              and  fringe  benefits,   unemployment  and  workers   compensation
              insurance  premiums,  pension plan contributions and other similar
              premiums and

<PAGE>

                                      -4-

              contributions   paid  or  provided  to  employees  directly  or  a
              reasonable  proportion thereof engaged in the maintenance,  repair
              or  operation  of  the  Building,   amounts  paid  to  independent
              contractors for any services in connection with such  maintenance,
              repair  or  operation,  the  cost  of  management  fees  (but  not
              exceeding  fifteen  percent (15%) of operating  costs),  and other
              indirect  expenses  to the extent  allocable  to the  maintenance,
              repair and  operation of the  Building and Common Area  Facilities
              and all other expense of every nature  incurred in connection with
              the  maintenance,  repair and operation of the Building and Common
              Area Facilities; and

       (ii)   the costs of any of the items  cited in  paragraph  (i) above that
              vary with the level of occupancy of the Building  (such as but not
              limited  to  cleaning  and  janitorial  costs,  garbage  and waste
              collection  and the  cost of  utilities)  shall  be  adjusted  and
              included  in the  Operating  Costs as if the  Building  were  100%
              occupied (hereinafter referred to as "Gross Up"). This Gross Up is
              for the sole purpose of equitably  dividing the cost of such items
              among the  tenant(s)  actually  occupying  the  Building and is to
              ensure that:  (a) this Lease is on an absolutely  net net basis to
              the Landlord;  and (b) the Landlord is not  subsidizing any tenant
              in the Building for costs that would  otherwise be paid in full by
              the tenant if the Building was in fact 100% occupied.  For further
              clarity  the  Landlord  shall  not  profit  from the terms of this
              paragraph  and any  Gross  Up shall be net  revenue  neutral  with
              respect to cost recovery to the Landlord; and

       (iii)  Operating  Costs shall  exclude debt service,  and all  management
              costs  not  allocable  to  the  actual  maintenance,   repair  and
              operation of the  Building  (such as that  incurred in  connection
              with  leasing  and rental  advertising)  and shall  exclude  those
              amounts noted on Schedule "G" hereto.

       "Property" means the Land and Building.

       "Proportionate  Share" shall mean the fraction which has as its numerator
       the Rentable Area of the Leased  Premises and has as its  denominator the
       total  Rentable  Area of the Building,  whether  leased or not. The total
       Rentable Area of the Leased Premises shall be adjusted from time to time,
       as may be  reasonably  necessary,  to give  effect to any  structural  or
       functional changes affecting the calculation of total Rentable Areas.

       "Rent" means Base Rental and Additional Rent.

       "Rentable Area" in this Lease means:

       (i)    in the case of a single  tenancy on a whole floor of the Building,
              all areas  within  the  inside  finished surface  of the  dominant
              portion  of the  permanent  outer  Building  walls  and  shall  be
              computed by measuring the inside finished  surface of the dominant
              portion of the permanent  outer  Building  walls and shall include
              Service  Areas and any special  stairs  and/or  elevators  for the
              specific sole use of that floor,  but excluding  stairs,  elevator
              shafts,  flues,  pipe shafts and  vertical  ducts and the like and
              their   enclosing  walls  (the  "Vertical   Openings"),   with  no
              deductions  for columns or  projections  necessary to the Building
              plus a gross-up  factor for ground  floor  services in common with
              other   tenants,   including,   but  not  limited  to  vestibules,
              corridors,  elevator lobbies, mechanical,  electrical,  telephone,
              mail,  garbage and janitor's rooms, such factor to be based upon a
              ratio which the ground floor Service  Areas of the Building  bears
              to the gross floor area,  less Vertical  Openings of the Building;
              and

       (ii)   in the case of a floor of the Building to be occupied by more than
              one tenant,

<PAGE>

                                      -5-

              all areas from the inside finished surface of the dominant portion
              of the  permanent  outer  Building  walls to the Tenant's  side of
              corridors and/or other permanent  interior walls and to the centre
              of demising  partitions  which  separate  the area  occupied  from
              adjoining  rentable  premises,  herein  referred to as the "Usable
              Area",  plus a gross-up  factor for the Service Areas on the floor
              in common with other tenants on the same floor, including, but not
              limited to, corridors,  elevator lobbies, mechanical,  electrical,
              telephone and janitor's rooms exclusively  serving the floor, such
              factor to be based  upon a ratio  which the  Service  Areas of the
              floor  bear to the sum of the Usable  Area of the  floor,  plus an
              additional  gross-up  factor for ground  floor  services in common
              with other  tenants,  including,  but not limited to,  vestibules,
              corridors,  elevator lobbies, mechanical,  electrical,  telephone,
              mail,  garbage and janitor's rooms, such factor to be based upon a
              ratio which the ground floor Service  Areas of the Building  bears
              to the gross floor area, less Vertical Openings of the Building.

       "Rules  and  Regulations"  means  the rules and regulations  attached  as
       Schedule "C".

       "Service  Areas"  shall mean the area of  corridors,  elevator,  lobbies,
       service  elevator  lobbies,  washrooms,  air-cooling  rooms,  fan  rooms,
       janitor's  closets,  telephone and  electrical  closets and other closets
       serving the Leased  Premises  in common  with other  premises on the same
       floor.

       "Taxes"  means  all  taxes,   rates,   duties,   levies  and  assessments
       whatsoever,  whether  municipal,   parliamentary  or  otherwise,  levied,
       imposed or assessed  against the  Building,  Common  Areas or Common Area
       Facilities or upon the Landlord in respect thereof  including Capital Tax
       and commercial concentration tax, or from time to time levied, imposed or
       assessed in the future in lieu thereof,  or in addition thereto,  whether
       now  contemplated  or not,  and those  levied,  imposed or  assessed  for
       education,  schools and local  improvements  and  including all costs and
       expenses  (including legal and other  professional  fees and interest and
       penalties on deferred  payments),  incurred by the Landlord in good faith
       in contesting, resisting or appealing any taxes, rates, duties, levies or
       assessments,  but  excluding  taxes and  license  fees in  respect of any
       business  carried on by tenants and occupants of the Building  (including
       the  Landlord)  to the extent such taxes are not levied in lieu of taxes,
       rates,  duties,  levies and assessments  against the Building or upon the
       Landlord  in respect  thereof,  and shall also  include any and all taxes
       which may in future be levied in lieu of taxes as  hereinbefore  defined,
       and also including Large Corporations Tax or any similar or successor tax
       in lieu thereof or in addition thereto assessed upon the Landlord.

       "Term" means the term of the Lease stipulated in paragraph 2.2.

       "Utilities"  means  electricity as described in Article 6.2,  natural gas
       and any other utility required in the operation of the Building.

ARTICLE 2.00 - LEASE TERM AND PAYMENTS

2.1    Demise.   In  consideration  of  the  rents,   covenants  and  agreements
       hereinafter  reserved and  contained,  the Landlord  hereby leases to the
       Tenant,  for the exclusive use of the Tenant, the Leased Premises for the
       Term.

2.2    Term.  The Lease  shall have a term of ten (10) years  commencing  on the
       Commencement  Date and  ending  on the date  ten (10)  years  thereafter,
       unless such term shall be sooner  terminated as hereinafter  provided and
       subject to the  Tenant's  right to extend the Term as provided in Section
       13.4 hereof.

<PAGE>

                                       -6-

2.3    Base Rental.  THE TENANT SHALL PAY yearly and every year during the first
       five (5) years of the within Term the sum of  $350,000.00 of lawful money
       of Canada in twelve (12) equal  monthly  installments of  $29,166.67,  in
       advance,  the first of such  instalment to become due and payable on the
       Commencement Date (the "Base Rental").

       THE TENANT SHALL PAY yearly and every year during the last five (5) years
       of the within Term the sum of  $400,000.00  of lawful  money of Canada in
       twelve (12) equal monthly  installments of $33,333.33,   in advance,  the
       first of such  instalment to become due and  payable on the first day of
       the sixth (6th) year following the Commencement Date (the "Base Rental").

       The  aforesaid  annual  Base  Rental  is  calculated  on the basis of the
       Rentable Area of the Leased Premises being 25,000 square feet at a yearly
       rate of $14.00 for each  square  foot of  Rentable  Area during the first
       five (5) years of the within Term and at a yearly rate of $16.00 for each
       square foot of Rentable Area during the last five (5) years of the within
       Term.

       The Landlord shall deliver to the Tenant a certificate  from an architect
       certifying  the area of the Leased  Premises in  accordance  with current
       BOMA Standards.

       IF THE TERM  COMMENCES  on any day other than the first day of a month or
       ends on any day other than the last day of the month, the Base Rental and
       additional rental for the fractions of a month at the commencement and at
       the end of the Term shall be adjusted pro rata. All Base Rental  payments
       shall be payable on the first of each month.

       If the  Leased  Premises  are  completed  by the  Landlord  prior  to the
       Commencement  Date,  the Tenant  shall be  entitled  to occupy the Leased
       Premises  prior to the  Commencement  Date for  purposes of readying  the
       Leased Premises for the Tenant's use. During such pre-term occupancy, the
       Tenant will only be responsible for paying for utilities  consumed in the
       Leased Premises.  However,  it is agreed and understood that the Landlord
       is not  representing  that it will complete the Leased  Premises prior to
       the Commencement Date.

       If for any reason the Landlord is delayed in  delivering  or is unable to
       give  possession  of the Leased  Premises to the Tenant in the  condition
       required   pursuant  to  the  terms  of  this  Lease  on  or  before  the
       Commencement  Date  then  the  Tenant  shall,  subject  to its  right  to
       terminate as  hereinafter  set out, take  possession on the date when the
       Landlord  delivers  possession  to the Tenant in the  condition  required
       pursuant  to the terms of this Lease and the  Commencement  Date shall be
       redefined as such date. Notwithstanding the foregoing, if the Landlord is
       unable to deliver  possession  of the Leased  Premises  in  substantially
       completed  condition to the Tenant in the condition  required pursuant to
       the terms of this Lease by a date which is six (6) months  subsequent  to
       the 15th of  December,  1999,  then within 3 days of such date the Tenant
       shall have the option in its sole  discretion  to declare this Lease null
       and void and the parties shall have no further obligation to one another.
       If the Tenant  does not deliver  such  notice in writing to the  Landlord
       within 3 days of such date,  then the Tenant shall have no further  right
       to terminate  this Lease and the  Commencement  Date shall mean that date
       when the Landlord actually delivers  possession of the Leased Premises to
       the Tenant in the condition required pursuant to the terms of this Lease.

2.4    Prepaid Rent. Deleted intentionally.

2.5    Security Deposit. Deleted intentionally.

2.6    Post-Dated Cheques

       The Tenant  shall  deliver to the  Landlord,  prior to the Tenant  taking
       possession of the Premises,  twelve (12)  post-dated  cheques each in the
       amount equal to the monthly Base Rental plus the Additional Rent payments
       required under this Lease.

<PAGE>

                                       -7-

       One month prior to the first and subsequent  anniversaries  of the Lease,
       the  Tenant  agrees to  deliver  twelve  (12)  post-dated  cheques to the
       Landlord.

       Notwithstanding  this  provision,  the Tenant  shall not be  obligated to
       provide postdated cheques unless it is habitually late in making payments
       pursuant to this Lease,  which shall mean three (3) late  payments in any
       twelve (12) month period.

ARTICLE 3.00 - LANDLORD AND TENANT COVENANTS

3.1    Landlord Covenants.        The Landlord covenants with the Tenant:

       (a)    Quiet Enjoyment. To provide for quiet enjoyment.

       (b)    Interior  Climate Control and Utilities.  To provide to the Leased
              Premises during Normal Business Hours, necessary utilities for the
              use of the Leased  Premises  by the Tenant  and  processed  air by
              means  of  a  system  for  heating  and  cooling,   filtering  and
              circulating,   processed   in   such   quantities,   and  at  such
              temperatures  as shall  be  reasonable  in  accordance  with  good
              standards of interior  climate  control  generally  pertaining  to
              normal  occupancy  of premises for office  purposes.  The Landlord
              shall have no responsibility  for inadequacy of the performance of
              the said  system if the  Leased  Premises  depart  from the design
              criteria.

       (c)    Elevators.  Subject to the  supervision of the Landlord and except
              when  repairs  are being  made  thereto, to furnish for use by the
              Tenant and its employees and invitees in common with other persons
              entitled  thereto  reasonable   standards  of  passenger  elevator
              service to the Leased  Premises.  The Tenant shall be  responsible
              for any  damages  caused  to the  elevator  as a result  of taking
              possession  or giving up  possession  of the Leased  Premises  and
              shall pay such costs forthwith upon demand as Additional Rent.

       (d)    Entrances, Lobbies,  Etc..  To permit the Tenant and its employees
              and  invitees  to have  the use in  common  with  others  entitled
              thereto  of the  Common  Areas,  Common  Area  Facilities,  common
              entrances,  lobbies,  stairways,  elevators  and  corridors of the
              Building  giving  access to the Leased  Premises  (subject  to the
              Rules and Regulations and such other reasonable limitations as the
              Landlord may from time to time impose).

       (e)    Washrooms. To permit the Tenant and its employees and invitees, in
              common with others entitled thereto to use the washrooms available
              to the  Leased  Premises on each floor of the Building upon which
              any part of the Leased Premises is located.

       (f)    Janitor Service.  To cause when reasonably  necessary from time to
              time the floors and windows of the Leased Premises to be swept and
              cleaned and the desks, tables and other furniture of the Tenant to
              be dusted, all in keeping with a first-class office building, such
              work   shall  be  done  at  the   Landlord's   direction   without
              interference by the Tenant, its servants or employees.

        (g)   Maintenance  of Common Areas.  To cause the Common  Areas,  Common
              Area Facilities,  elevators, common entrances, lobbies, stairways,
              corridors,  washrooms and other parts of the Building from time to
              time provided for common use and enjoyment to be swept, cleaned or
              otherwise  maintained  substantially in keeping with a first-class
              office building.

3.2    Tenant Covenants. The Tenant covenants with the Landlord:

       (a)    Rent. To pay Base Rental and Additional Rent.

<PAGE>

                                       -8-

       (b)    Permitted Use. To use the Leased  Premises only for the purpose of
              general  business  offices and any other uses allowed  pursuant to
              applicable  by-laws if approved by the Landlord acting  reasonably
              and not to use or permit  to be used the  Leased  Premises  or any
              part thereof for any other purpose or business.

       (c)    Waste and Nuisance.  Not to commit or permit any waste,  damage or
              injury to the Leased Premises including the Leasehold Improvements
              and trade fixtures therein, reasonable wear and tear excluded, any
              overloading of the floors thereof, any nuisance therein or any use
              or manner of use causing  unreasonable  annoyance to other tenants
              and occupants of the Building.

       (d)    Condition.  Not to permit the Leased Premises to become  hazardous
              or permit unreasonable quantities of waste or refuse to accumulate
              therein  and at the end of each  business  day to leave the Leased
              Premises  in a  condition  such as to  reasonably  facilitate  the
              performance  of  the  Landlord's  janitor  and  cleaning  services
              referred to herein.

       (a)    By-Laws. To comply at its own expense with all municipal, federal,
              provincial,  sanitary,  fire, building and safety statutes,  laws,
              by-laws, regulations, ordinances, orders or regulations pertaining
              to the operation and use of the Leased Premises,  the condition of
              the  Leasehold   Improvements,   trade  fixtures,   furniture  and
              equipment  installed  by the Tenant  therein and the making by the
              Tenant of any repairs, changes or improvements therein.

       (f)    Fire Exit Doors. To permit the installation by the Landlord of all
              doors in the  exterior  wall of the Leased  Premises  necessary to
              comply  with  the   requirements  of  any  statute,  law,  by-law,
              regulation, ordinance, order or regulation.

       (g)    Rules and  Regulations.  To  observe  and to cause its  employees,
              invitees  and  others  over  whom the  Tenant  can  reasonably  be
              expected to exercise  control,  the Rules and Regulations and such
              further and other reasonable rules and regulations and amendments
              and changes  therein as may  hereafter be made by the Landlord and
              notified to the Tenant.

       (h)    Overholding.  That  in  the  event  that  the  Tenant  remains  in
              possession of the Leased  Premises  after the  termination  of the
              original Term hereby created,  without other special agreement, it
              shall be at the monthly  Base Rental  equal to the Base Rental and
              Additional  Rent payable during the last month of the Term hereof,
              times two,  payable  on the first day of each and every  month and
              subject in other  respects to the terms of this  Lease,  including
              those  provisions   requiring  the  payment  of  Base  Rental  and
              Additional Rent in monthly installments.

 3.3   Signs and Directory. Subject to Section 13.8, the Tenant covenants not to
       permit, paint, display, inscribe, place or affix any sign, symbol, notice
       or lettering of any kind anywhere outside the Leased Premises (whether on
       the outside or inside of the  Building) or within the Leased  Premises so
       as to be  visible  from the  outside  of the  Leased  Premises,  with the
       exception only of an  identification  sign at or near the entrance to the
       Leased  Premises  and a  directory  listing  in  the  main  lobby  of the
       Building,  in each case  containing only the name of the Tenant and to be
       subject to the approval of the Landlord as to size, location, content and
       design criteria as established by the Landlord,  acting reasonably.  Such
       identification  sign and  directory  listing  shall be  installed  by the
       Landlord at the expense of the Tenant, which expense shall be the invoice
       cost plus 15% for an administration fee. The Landlord's acceptance of any
       name for  listing  upon the  directory  will not be  deemed,  nor will it
       substitute for the Landlord's consent if required by this Lease to any

<PAGE>

                                      -9-

       sublease, assignment or other occupancy of the Leased Premises.

3.4    Inspection  and Access.  The Landlord  shall be permitted to enter and to
       have its authorized  agents,  employees and contractors  enter the Leased
       Premises,  for the purpose of inspection,  window cleaning,  maintenance,
       providing janitor service, making repairs, alterations or improvements to
       the Leased  Premises or the Building,  or to have access to utilities and
       services and access panels which the Tenant agrees not to obstruct, or to
       determine the electric  light and power  consumption by the Tenant in the
       Leased  Premises and the Tenant shall provide free and unhampered  access
       for such  purposes  and shall not be  entitled  to  compensation  for any
       inconvenience,  nuisance,  discomfort  or loss  caused  thereby,  but the
       Landlord, in exercising its rights hereunder, shall proceed to the extent
       reasonably possible so as to minimize  interference with the Tenant's use
       and enjoyment of the Leased Premises.

3.5    Exhibiting Premises. The Landlord and its authorized agents and employees
       shall be permitted  entry to the Leased  Premises during the last six (6)
       months of the term for the  purpose  of  exhibiting  them to  prospective
       tenants or at any time for the  purposes of arranging  financing  for the
       Building, in each case, however, the Landlord shall proceed to the extent
       reasonably possible so as to minimize  interference with the Tenant's use
       and enjoyment of the Leased Premises.

3.6    Landlord's  Control.   The  Tenant  acknowledges  that  the  Common  Area
       Facilities  are  at  all  times  subject  to the  exclusive  control  and
       operation  of the  Landlord,  and the  Landlord  shall  have the right to
       construct improvements, alterations and additions thereto and to relocate
       the various facilities thereon.

3.7    Financial  Statements.  The Tenant will,  at the request of the Landlord,
       supply  copies of his  financial  statements  to the  Landlord  or to the
       mortgagees,  if any, on the said lands or a  prospective  mortgagee.  The
       Landlord  acknowledges that the only financial statements to be delivered
       are those which are public.

ARTICLE 4.00 - REPAIR AND DAMAGE

4.1    Tenant's Repairs. The Tenant covenants with the Landlord:

       (a)    to keep the Leased Premises in good and reasonable state of repair
              and consistent  with the general  standards of first-class  office
              buildings  in  Metropolitan  Toronto,  to perform  all repairs and
              replacements  as a prudent  tenant would do  (reasonable  wear and
              tear  excepted) to the Leased  Premises  including  all  Leasehold
              Improvements and all trade fixtures therein and all glass therein;

       (b)    that the Landlord may enter and view the state of repair from time
              to time and that the  Tenant  will  repair  if  required  to do so
              pursuant  to the  terms of this  Lease,  according  to  notice  in
              writing  and that the Tenant  will leave the Leased  Premises in a
              good and reasonable state of repair; and

       (c)    that if any part of the  Building  other than the Leased  Premises
              becomes out of repair, damaged or destroyed through the negligence
              or misuse of the Tenant or its employees,  invitees or others over
              whom the Tenant can  reasonably  be expected to exercise  control,
              the  expense  of  repairs  or  replacements  thereto  necessitated
              thereby shall be the responsibility of the Tenant.

4.2    Abatement  and  Termination.  It is agreed  between the  Landlord and the
       Tenant that:

<PAGE>

                                      -10-

       (a)    In the event of damage to the Leased  Premises or to the  Building
              affecting access or services  essential to the conduct of business
              in the Leased  Premises  and if the damage is such that the Leased
              Premises  or  any   substantial   part  thereof  is  rendered  not
              reasonably  capable  of use and  occupancy  by the  Tenant for the
              purposes  of its  business  for any period of time in excess of 10
              days, then

              (i)    unless  the  damage  was  caused  by  the  misuse,   fault,
                     negligence  of the  Tenant or its  employees,  invitees  or
                     others  under  its  control,  from  and  after  the date of
                     occurrence of the damage and until the Leased  Premises are
                     again reasonably capable of use and occupancy as aforesaid,
                     Base  Rental and  Additional  Rent shall abate from time to
                     time in  proportion  to the  part or  parts  of the  Leased
                     Premises not reasonably  capable of such use and occupancy,
                     and

              (ii)   unless this Lease is  terminated as  hereinafter  provided,
                     the Landlord or the Tenant as the case may be (according to
                     the nature of the damage and their  respective  obligations
                     to repair as provided herein,  it being understood that the
                     Tenant shall have the  obligation to repair and replace all
                     Leasehold  Improvements  and all Tenant's  trade  fixtures)
                     shall repair such damage with all reasonable diligence, but
                     to the extent  that any part of the Leased  Premises is not
                     reasonably  capable of such use and  occupancy by reason of
                     damage which the Tenant is  obligated to repair  hereunder,
                     any  abatement  of Rent to which the  Tenant  is  otherwise
                     entitled  hereunder shall not extend later than the time by
                     which  repairs by the Tenant  ought to have been  completed
                     with reasonable diligence; and

       (b)    if either the entire or substantially  all of the Leased Premises,
              or premises whether of the Tenant or other tenants of the Building
              comprising  in the  aggregate  50% or more of the Rentable Area of
              the Building are  substantially  damaged or destroyed by any cause
              to such an extent in the reasonable opinion of the Landlord cannot
              be repaired or rebuilt within 160 days after the occurrence of the
              damage or destruction, the Landlord may at its option, exercisable
              by  written  notice to the Tenant  given  within 30 days after the
              occurrence of such damage or  destruction  terminate this Lease in
              which event  neither the Landlord nor the Tenant shall be bound to
              repair as provided  herein and the Tenant shall instead deliver up
              possession of the Leased  Premises to the Landlord with reasonable
              expedition  but in any event within 60 days after delivery of such
              notice of termination  and rent shall be  apportioned  and paid to
              the date upon which possession is so delivered up (but, subject to
              any abatement to which the Tenant may be entitled under  paragraph
              (a) of this  clause  4.2 by reason of the Leased  Premises  having
              been  rendered in whole or in part not  reasonably  capable of use
              and  occupancy),  but  otherwise the Landlord or the Tenant as the
              case may be  (according  to the  nature  of the  damage  and their
              respective  obligations to repair described in 4.2 (a) (ii)) shall
              repair such damage with reasonable diligence.

ARTICLE 5.00 - TAXES AND OPERATING COSTS

5.1    Net Net Lease.  The Tenant  acknowledges  and agrees  that it is intended
       that this Lease is a completely  carefree net net lease to the  Landlord,
       except as expressly  herein set out, that the Landlord is not responsible
       during  the Term for any  costs,  charges,  expenses  and  outlays of any
       nature whatsoever arising from or relating to the Leased Premises, or the
       use and  occupancy  thereof,  or the  contents  thereof  or the  business
       carried on therein,  except as expressly  set out herein,  and the Tenant
       shall pay all  charges,  impositions,  costs and expenses of every nature
       and kind

<PAGE>

                                      -11-

       relating to the Leased Premises, except as expressly set out herein.

5.2    Landlord's  Tax  Obligations.  The  Landlord  covenants  with the Tenant,
       subject to the provisions  herein,  to pay all Taxes promptly when due to
       the taxing authority or authorities having jurisdiction.

5.3    Tenant's Tax Obligations. The Tenant covenants with the Landlord:

       (i)    to pay promptly  when due to the taxing  authority or  authorities
              having   jurisdiction  all  taxes,  rates,   duties,   levies  and
              assessments  whatsoever,   whether  municipal,   parliamentary  or
              otherwise, levied, imposed or assessed in respect of any and every
              business carried on by the Tenant, subtenants, licensees, or other
              occupants  of the  Leased  Premises  or in  respect  of the use or
              occupancy thereof (including license fees);

       (ii)   to pay promptly to the  Landlord  when  demanded or otherwise  due
              hereunder:

              (1)    all Taxes charged in respect of all Leasehold  Improvements
                     and trade  fixtures and all furniture  and equipment  made,
                     owned or  installed  by or on behalf  of the  Tenant in the
                     Leased Premises as Additional Rent;

              (2)    if by reason of the act, election or religion of the Tenant
                     or any  subtenant,  licensee  or  occupant  of  the  Leased
                     Premises,  the Leased Premises or any part of them shall be
                     assessed for the support of Separate Schools, the amount by
                     which the Taxes so payable  exceed  those  which would have
                     been payable if the Leased  Premises had been  assessed for
                     the support of Public Schools; and

              (3)    the Tenant's  Proportionate  Share of Taxes  as  Additional
                     Rent in the manner stipulated herein; and

       (iii)  notwithstanding   any  other  provisions  of  this  Lease  to  the
              contrary,  the Tenant shall pay to the Landlord, at such times and
              in such manner as the Landlord may direct, without duplication, an
              amount  equal  to  all  goods  and  service  taxes,  sales  taxes,
              value-added  taxes or any other taxes imposed with respect to Base
              Rental,  Additional Rent or other amounts payable by the Tenant to
              the  Landlord   under  this  Lease,   howsoever   such  taxes  are
              characterized.  The amount payable by the Tenant  hereunder  shall
              not be  deemed  to be  Base  Rental  or  Additional  Rent  but the
              Landlord  shall  have  all of the same  rights  and  remedies  for
              recovery  of same  as it has  for  recovery  of  Base  Rental  and
              Additional Rent hereunder.

       Whenever requested by the Landlord the Tenant will deliver to it receipts
       for payment of all taxes, rates,  duties,  levies and assessments payable
       by the Tenant  hereof and furnish such other  information  in  connection
       therewith as the Landlord may reasonably require.

5.4    Method of Payment of Taxes.  The Tax payments  required to be made by the
       Tenant to the Landlord  under the  provisions of 5.3 (ii) herein shall be
       estimated  by the  Landlord,  and the Tenant shall pay to the Landlord in
       addition to the monthly  payments of Base Rental  hereinbefore  reserved,
       one-ninth of the  estimated  annual tax payments in the months of January
       to September,  both  inclusive,  in each calendar year with an adjustment
       being made when the property tax bill respecting the Building is received
       by the Landlord for each year. The Tenant shall within sixty (60) days of
       being  invoiced  pay to  the  Landlord  such  additional  sums  as may be
       required  in order  that out of such  monthly  additional  payments,  the
       Landlord  may pay the whole  amount of the  annual  taxes  payable by the
       Tenant  as  the  installments  thereof  fall  due;  and  if  the  monthly
       additional payments so paid by the

<PAGE>

                                      -12-

       Tenant to the Landlord exceed in total the Tenant's  Proportionate  Share
       of the annual property tax bill with respect to the Building and Lands of
       which the Leased Premises form part, then the excess shall be adjusted by
       the  Landlord in favour of the Tenant by applying  such excess on account
       of the next  ensuing  rental  payments  due  (following  the issue of the
       yearly  statement) and such next ensuing rental payments shall be reduced
       by such excess  accordingly,  unless it is the last year of the Term,  in
       which case, such excess shall be paid by the Landlord to the Tenant which
       obligation  to pay  shall  survive  any  termination  of  this  Lease  or
       expiration of the Term.  The Landlord  shall forward to the Tenant copies
       of all notices or tax bills  relating to the imposition of property taxes
       or other charges required  hereunder to be paid as to part or all thereof
       by the  Tenant.  In the event  that the  Landlord  is unable to obtain or
       determine a separate allocation of taxes payable by the Tenant under this
       Lease, the Landlord shall have the right to make an allocation, but shall
       be obligated to act reasonably and not arbitrarily.

5.5    Operating  Costs.  During the Term of this Lease, the Tenant shall pay to
       the Landlord its  Proportionate  Share of Operating  Costs.  Prior to the
       commencement  of the  Term of this  Lease  and the  commencement  of each
       fiscal period selected by the Landlord  thereafter which commences during
       the Term the Landlord  shall  estimate the amount of Operating  Costs and
       the Tenant's Proportionate Share thereof for the ensuing fiscal period or
       (if applicable)  broken portion  thereof,  as the case may be, and notify
       the Tenant in writing of such estimate.  The amount so estimated shall be
       payable in equal monthly  installments  in advance over the fiscal period
       or broken  portion  thereof  in  question,  each such  installment  being
       payable on each monthly  rental  payment date provided in clause 2.3. The
       Landlord may from time to time alter the fiscal period selected, in which
       case,  and in the case where only a broken  portion of a fiscal period is
       included with the Term, the  appropriate  adjustment in monthly  payments
       shall be made.  From time to time during a fiscal period the Landlord may
       re-estimate the amount of Operating Costs and the Tenant's  Proportionate
       Share  thereof,  in which event the  Landlord  shall notify the Tenant in
       writing of such  re-estimate and fixed monthly  installments for the then
       remaining  balance of such fiscal period or broken  portion  thereof such
       that,  after  giving  credit for  installments  paid by the Tenant on the
       basis  of  the  previous  estimate  or  estimates,  the  Tenant's  entire
       Proportionate  Share of  Operating  Costs will have been paid during such
       fiscal period or broken period thereof.  As soon as practicable after the
       expiration  of  each  fiscal  period  the  Landlord  shall  make a  final
       determination  of Operating  Costs and the Tenant's  Proportionate  Share
       thereof for such fiscal period or (if applicable)  broken portion thereof
       and shall  provide a statement  to the Tenant and the parties  shall make
       the appropriate  readjustment.  Each 12 month period ending December 31st
       shall be deemed to be an accounting year for adjusting the said Operating
       Costs and within 120 days after the end of each such accounting year, the
       Landlord  shall compute the said costs for such  accounting  year and the
       Proportionate Share of the Tenant therefor and shall submit to the Tenant
       a statement to reflect the Operating Costs  specifically  permitted under
       this Lease,  and the said  Proportionate  Share thereof shall be borne by
       the Tenant. To the extent that the Tenant's  Proportionate  Share of such
       costs for such  accounting  year shall be greater  than the total  amount
       actually  paid by the Tenant by said monthly  payments in respect of such
       year the  difference  shall be paid by the Tenant to the Landlord  within
       thirty  (30) days  after  receipt by the  Tenant of such  statement.  Any
       excess  payments  shall be applied by reducing  the next  ensuing  rental
       payment(s)  by the amount of such  excess,  unless it is the last year of
       the Term, in which case, such excess shall be paid by the Landlord to the
       Tenant which  obligation  to pay shall  survive any  termination  of this
       Lease or  expiration  of the  Term.  The said  accounting  period  may be
       modified by the  Landlord  if  reasonably  necessary.  The Tenant may not
       claim a readjustment  in respect to the Tenant's  Proportionate  Share of
       Operating  Costs  based upon any error of  assessment,  determination  or
       calculation  thereof unless claimed in writing prior to the expiration of
       one year after the fiscal period to which the Operating Costs relate.

<PAGE>

                                      -13-

5.6    Payment of Additional  Rent. Any Additional  Rent provided for under this
       Lease  unless  otherwise  provided  herein,  shall  become  due with each
       instalment of monthly Base Rental.

ARTICLE 6.00 - UTILITIES AND ADDITIONAL SERVICES

6.1    Water and Telephone.  The Landlord shall furnish appropriate openings for
       bringing  telephone services to the Leased Premises and shall provide hot
       and cold water to  washrooms  in the  Leased  Premises  and to  washrooms
       available for the Tenant's use in common with others entitled thereto.

6.2    Electricity.  The Tenant  shall pay  throughout the Term  promptly to the
       Landlord (unless paid directly to Hydro authorities  pursuant to separate
       billing) as Additional Rent when demanded:

       (i)    the cost of  electric  light  and  power  supplied  to the  Leased
              Premises   monthly   based  on  the   electric   light  and  power
              requirements  of the Tenant on a pro rata basis as determined from
              time to time during the Term by the  Landlord  acting  reasonably;
              and

       (ii)   the cost of cleaning,  maintaining  and  servicing in all respects
              all electric  lighting  fixtures in the Leased Premises  including
              the cost of replacement of electric light bulbs,  tubes,  starters
              and ballasts used to replace those  installed at the  commencement
              of the Term. Such cleaning, maintaining, servicing and replacement
              shall  be  within  the  exclusive  right  of the  Landlord.  It is
              understood and agreed that the costs described in this sub-section
              (ii)  shall be  charged  to the  Tenant as an  Additional  Service
              payable upon receipt of invoice from the Landlord.

6.3    Additional  Services.  The  Landlord,  if it shall  from  time to time so
       elect, shall have the exclusive right, by way of Additional Services,  to
       provide or have its designated agents or contractors  provide any janitor
       or cleaning  service to the Leased  Premises  and Common Area  Facilities
       required  by the Tenant  which are  additional  to those  required  to be
       provided by the Landlord  hereunder,  including the  Additional  Services
       which the Landlord agrees to provide by arrangement, and to supervise the
       moving of furniture or equipment of the Tenant in and out of the Building
       where such moving of furniture or equipment  would be  disruptive  to the
       normal business of the Building, and the making of repairs or alterations
       conducted  within the Leased Premises  affecting Base Building,  building
       systems or Leasehold  Improvements.  The  reasonable  cost of  Additional
       Services provided to the Tenant,  whether the Landlord shall be obligated
       hereunder or shall elect to provide them as Additional Services, shall be
       paid to the  Landlord by the Tenant from time to time within  thirty (30)
       days following receipt of invoices  therefor from the Landlord.  Costs of
       Additional  Services  charged  directly  to the Tenant and other  tenants
       shall be credited in computing Operating Costs.

ARTICLE 7.00 - ASSIGNING AND SUBLETTING

7.1    Assignments and Sublettings.  The Tenant covenants with the Landlord that
       it will not assign,  sublet,  license or part with the  possession of the
       Leased  Premises  or any part  thereof,  or share the  occupation  of the
       Leased Premises, or any part thereof, without the consent of the Landlord
       in writing first had and obtained such consent not to be  unreasonably or
       arbitrarily  withheld or  delayed.  Provided  that as a condition  of the
       granting  of  its  consent,   the  Landlord  may  require  any  assignee,
       subtenant,  licensee  or  occupant  of the Leased  Premises to execute an
       agreement  whereby he, it or they attorn to and become the tenants of the
       Landlord as if he, it or they had executed this Lease,  or, except in the
       case of an absolute assignment

<PAGE>

                                       -14-

       of this Lease, to execute an acknowledgement  that all the sublessee's or
       undertenant's  estate,  right and interest in and to the Leased  Premises
       absolutely terminates upon the surrender,  release,  disclaimer or merger
       of this Lease  notwithstanding  the provisions of the Landlord and Tenant
       Act of Ontario,  R.S.O.  1980,  Chapter 232 and  amendments  thereof with
       specific reference to Paragraphs 21 and 39 (2) thereof,  or other similar
       statute.  The  Tenant  shall  furnish  to  the  Landlord  copies  of  any
       assignment,  sublease,  license or other agreement  herein  contemplated.
       Notwithstanding  any other  provision  in this  section,  no  assignment,
       subletting,  licensing or parting with  possession of the Leased Premises
       shall in any way  release  or be deemed to  release  the  Tenant  (or any
       guarantor  hereof) from their  obligations under the terms of this Lease.
       Provided  further  that the  proposed  assignee,  subtenant,  licensee or
       occupant of the Leased  Premises  shall be required to provide  financial
       statements or other financial information as the Landlord may require. It
       is agreed that the Landlord may consider in determining  whether to grant
       consent among other  matters,  the  following:  the personal and business
       history  of the  proposed  assignee,  occupant,  sublessee  and  its  key
       employees.  The  Tenant  agrees to pay the  reasonable  legal fees of the
       Landlord's  solicitor  relating  to the  preparation  of  the  Landlord's
       consent, and determination as to whether to give the consent.

       If by sale,  transfer or other disposition of its shares,  the control of
       the Tenant is altered  so that 51% of the shares are  transferred  in any
       manner,  then same shall be deemed as an assignment and the provisions of
       this paragraph shall apply. The Tenant covenants and agrees to advise the
       Landlord  forthwith if such a transfer is  contemplated.  This  provision
       shall not apply if the Tenant is a public company.

       Notwithstanding the foregoing, the Tenant shall not be required to obtain
       the consent of the Landlord in the event of a sublease or  assignment  to
       any of its parent,  subsidiaries,  or  affiliated  companies  (within the
       meaning of the Ontario Business  Corporations Act, as amended or replaced
       from time to time)  provided  the Tenant  provides  the Landlord at least
       fifteen  (15) days prior  written  notice and  provided  further that the
       assignee or sublessee signs an acknowledgement In the Landlord's standard
       form that it will be bound by all the terms and conditions of this Lease.
       Furthermore,  upon Landlord's  acceptance of the sublessee or assignee as
       such,  the Tenant shall not be released from any  obligations  under this
       Lease.

       In the  event of any  subletting  by the  Tenant  by  virtue of which the
       Tenant  receives  rent in the  form of  cash,  goods,  services  or other
       considerations  from the subtenant  which is higher than the rent payable
       hereunder to the  Landlord  for the premises so sublet,  the Tenant shall
       pay any such  excess to the  Landlord,  in addition to all rent and other
       costs  payable  hereunder,  for the period of time during  which the said
       subtenant remains in possession of the premises sublet to it.

       If the Tenant  herein  shall  receive  from any  assignee  of this Lease,
       either directly or indirectly, any Consideration (as hereinafter defined)
       for the  assignment of this Lease,  either in the form of cash,  goods or
       services,  the Tenant shall  forthwith  pay an amount  equivalent to such
       Consideration  to the  Landlord  and same  shall be deemed to be  further
       Additional Rent hereunder.  For greater certainty and notwithstanding the
       foregoing,   "Consideration"  shall  only  include  actual  consideration
       received by the Tenant (in the form of cash,  goods or services)  for the
       assignment  of the  Tenant's  interest  in the  Lease  only and shall not
       include  any  consideration  received  by the Tenant for any  assignment,
       transfer or sale of the Tenant's  business or the Tenant's  other assets,
       whether  related to, located at or associated with the Leased Premises or
       the business of the Tenant conducted therein.

       In calculating whether there is any additional  consideration  payable by
       an assignee or sublessee as hereinbefore  provided, no deduction shall be
       made for any commission payable to any agent or other party.

<PAGE>

                                      -15-

       If the Landlord has granted to the Tenant, named on page 1 of this Lease,
       any first  rights  of  refusal,  exclusive  rights  or  options  to lease
       additional  space or to purchase,  it is agreed and understood  that upon
       the Tenant assigning, subletting, licensing or parting with possession of
       the Leased Premises or any part thereof, the aforesaid rights referred to
       shall automatically become null and void.

       Notwithstanding the above provisions, within ten (10) business days after
       the  receipt by the  Landlord  of such  request  for  consent  and of all
       information  which the  Landlord  shall  have  requested  hereunder,  the
       Landlord  shall  have  the  right  upon  written  notice  of  termination
       submitted  to the  Tenant to, if the  request is to assign  this Lease or
       sublet the whole of the Leased Premises, cancel and terminate this Lease,
       or to, if the  request is to sublet a part of the Leased  Premises  only,
       cancel and  terminate  this Lease with respect to such part, in each case
       as of a termination  date to be  stipulated in the notice of  termination
       which shall be ninety (90) days following giving of such notice. However,
       if such notice of termination is given by the Landlord,  the Tenant shall
       have five (5) days from  receipt  thereof to  withdraw  the  request  for
       consent, in which event, the notice of termination shall be nullified. If
       the request for consent is not withdrawn by the Tenant as aforesaid, then
       the Tenant shall  surrender the whole or part, as the case may be, of the
       Leased  Premises in accordance  with such notice of termination  and Base
       Rental and Additional  Rent shall be apportioned  and paid to the date of
       surrender and, if only a part of the Leased Premises is surrendered, Base
       Rental and  Additional  Rent shall,  after the date of  surrender,  abate
       proportionately. If the Landlord does not elect to terminate as aforesaid
       and if consent to  sublease  or assign  will be  granted,  the Tenant may
       assign  or  sublet,  as the case may be,  only  upon the terms and to the
       party set out in the offer submitted to the Landlord as aforesaid.

ARTICLE 8.00 - FIXTURES AND IMPROVEMENTS

8.1    Installation  of Fixtures  and  Improvements.  The Tenant shall not make,
       erect, install or alter any Leasehold Improvements in the Leased Premises
       without  having  requested  and obtained  the  Landlord's  prior  written
       approval which the Landlord shall not unreasonably delay or withhold.  In
       making,  erecting,  installing or altering any Leasehold Improvements the
       Tenant will not alter or interfere with any installations which have been
       made by the Landlord  without the prior written  approval of the Landlord
       and in no event shall it alter or  interfere  with window  coverings  (if
       any) installed by the Landlord on exterior windows.  The Tenant's request
       for any  approval  hereunder  shall be in writing and  accompanied  by an
       adequate  description of the  contemplated  work and, where  appropriate,
       working drawings and specifications  thereof. All work to be performed in
       the Leased Premises shall be performed by reputable  contractors approved
       by the Landlord. The Landlord reserves the right to require the Tenant to
       utilize the  contractor(s) of the Landlord where Base Building,  building
       systems and/or  warranties may be affected  provided the Landlord  agrees
       that charges by such  contractors  shall be in keeping with that which an
       arms length  contractor would charge.  The cost of all such work shall be
       estimated  by the Landlord in advance and such  estimate  approved by the
       Tenant prior to work commencing.  All such work shall be performed at the
       Tenant's  expense and the Tenant shall be responsible for application and
       payment of all fees in  connection  with any permits  required.  All such
       work shall be subject to inspection by and the reasonable  supervision of
       the  Landlord,  as an  Additional  Service,  and  shall be  performed  in
       accordance with any reasonable  conditions or regulations  imposed by the
       Landlord and  completed in a good and  workmanlike  manner in  accordance
       with the  description of the work approved by the Landlord.  The Landlord
       shall  be  entitled  to  supervise  the  work  and  charge  the  Tenant a
       reasonable  supervision  fee.  The Tenant  shall be  obligated to pay any
       reasonable  consultant's  fees  incurred by the  Landlord  for review and
       approval of plans for  construction of any nature after the  Commencement
       Date as Additional Rent. The Landlord shall not charge any fees to review
       any plans and specifications save and except for reasonable out-of-pocket
       expenses including

<PAGE>

                                      -16-

       third party consultants.

 8.2   Liens and Encumbrances on Fixtures and  Improvements.  In connection with
       the  making,   erection,   installation   or   alteration   of  Leasehold
       Improvements  and  all  other  work or  installations  made by or for the
       Tenant in the  Leased  Premises  the  Tenant  shall  comply  with all the
       provisions of the Construction Lien Act (Ontario) and other statutes from
       time to time  applicable  thereto  and shall  promptly  pay all  accounts
       relating  thereto.  The Tenant will not create or cause to be created any
       mortgage,  conditional sale agreement or other  encumbrance in respect of
       its Leasehold Improvements or permit any such mortgage,  conditional sale
       agreement or other encumbrance to attach to the Leased Premises or to the
       Building and Common Area Facilities.  If and whenever any construction or
       other lien for work, labour, services or materials supplied to or for the
       Tenant  for the cost of which  the  Tenant  may be in any way  liable  or
       claims therefor shall arise or be filed or any such mortgage, conditional
       sales  agreement  or other  encumbrance  shall  attach,  the Tenant shall
       within  ten (10)  days  after  receipt  of  notice  thereof  procure  the
       discharge  thereof,  including any  certificate  of action  registered in
       respect  of any lien,  by  payment  or giving  security  or in such other
       manner as may be required or permitted by law failing  which the Landlord
       may in  addition  to all other  remedies  hereunder  avail  itself of its
       remedy  hereunder  and may make any  payments  required  to  procure  the
       discharge of any such liens or  encumbrances  and shall be entitled to be
       reimbursed   by  the  Tenant  as   provided   herein  and  its  right  to
       reimbursement  shall not be affected or impaired if the Tenant shall then
       or  subsequently  establish  or claim  that any  lien or  encumbrance  so
       discharged  was without  merit or excessive or subject to any  abatement,
       set-off or defense.

 8.3   Removal of Fixtures and  Improvements.  All Leasehold  Improvements in or
       upon the Leased Premises shall immediately upon the expiry of the Term or
       earlier  termination of this Lease, be and become the Landlord's property
       without  compensation  therefor  to the  Tenant.  Except  to  the  extent
       otherwise  expressly  agreed by the  Landlord  in  writing  no  Leasehold
       Improvements,  trade fixtures, furniture or equipment shall be removed by
       the Tenant from the Leased Premises either during or at the expiration or
       earlier  termination  of the Term except that (1) the Tenant shall at the
       end of the Term  remove  its trade  fixtures,  and (2) the  Tenant  shall
       remove its  furniture and equipment at the end of the Term and may remove
       its  furniture  and  equipment  during  the Term in the usual and  normal
       course of its  business  where such  furniture  or  equipment  has become
       excess for the Tenant's  purposes or the Tenant is substituting  therefor
       new  furniture  and  equipment.  The Tenant  shall,  in the case of every
       removal  either  during or at the end of the Term,  make good any  damage
       caused to the Leased Premises by the installation  and removal.  Provided
       that upon the termination of this Lease, the Tenant,  if requested by the
       Landlord, shall restore the interior of the Leased Premises to its former
       condition  immediately  prior to the  installation of such alterations or
       changes,  including the restoration of such standard fixtures as may have
       been installed by the Landlord, and if not so requested, any such changes
       or   alterations   shall  become  the  property  of  the   Landlord,   or
       alternatively,  the Tenant  shall  install such  comparable  fixtures and
       materials  as may then be in use.  Notwithstanding  any of the  foregoing
       provisions or any other  provisions in this Lease,  it is understood  and
       agreed that the Tenant  shall not be required to remove  those  Leasehold
       Improvements approved by the Landlord prior to their construction.

8.4    Occupational  Health and Safety.  The Tenant covenants and agrees that it
       will ensure that a  comprehensive  and rigorous health and safety program
       to protect  workers in the Leased  Premises is implemented to ensure that
       no accidents or injuries occur in connection  with the performance of any
       Tenant's  work.  The Tenant will indemnify the Landlord in respect of all
       claims, infractions, prosecutions, alleged infractions, losses, costs and
       expenses and any fines or proceedings relating to fines or other offenses
       under all occupational health and safety and any similar legislation that
       might be brought, or imposed against or suffered by the Landlord or

<PAGE>

                                      -17-

       any of its  officers,  directors  and  employees in  connection  with the
       performance of any Tenant's work.  Without  limiting the  obligations set
       out above in this Section 8.4, the Tenant will do at least the following:

       (a)    ensure that all obligations imposed by statute,  law or regulation
              on "constructors" or other persons completing or co-ordinating any
              Tenant's work are diligently and properly completed;

       (b)    co-operate   with  the  Landlord  in  having  any  Tenant's   work
              designated  as a separate  project so that the  Landlord  does not
              incur any  obligations as a constructor or obligations  similar to
              those  of a  constructor  at  law  or  by  regulation  imposed  in
              connection with the performance of any Tenant's work;

       (c)    comply  with  all  directions  that the  Landlord  may give to the
              Tenant in  connection  with the  performance  of any Tenant's work
              having regard to construction health and safety requirements; and

       (d)    provide to the Landlord whatever rights of access, inspection, and
              whatever  information,  documents  and other  matters the Landlord
              requires in order to ensure that the  Tenant's  obligations  under
              this Section are complied with.

ARTICLE 9.00 - INSURANCE AND LIABILITY

9.1    Landlord's Insurance. The Tenant will during the whole of the Term hereby
       granted as part of Operating  Costs, pay its  Proportionate  Share of all
       premiums  with  respect to  insurance  to be placed by the  Landlord  and
       described in this Section 9.1. The Landlord agrees to maintain during the
       Term, insurance coverages as follows:

       (i)    Property of Every Description (Building and Equipment) against the
              perils of  "All-Risks",  under form  providing  coverage  at least
              equivalent to Commercial  Building Broad Form I.A.O.  Form No. 700
              including "Building By-Laws  Endorsements",  and to be insured for
              the Replacement  Value,  without  allowance for  depreciation  and
              Stated Amount, and with no co-insurance requirement;

       (ii)   "Rental  Income" for the gross annual rental income on "All-Risks"
              basis,  as provided  under  Commercial  Building Broad Form I.A.O.
              Form 700  including  "Building  By-Laws  Endorsements",  providing
              coverage at least  equivalent to I.A.O.  Profits Form No. 551 with
              an eighteen (18) month indemnity period;

       (iii)  Broad  Form  Boiler  and   Machinery   Policy  on  a  blanket  and
              replacement  basis with limits for each  accident in an amount not
              less than the  replacement  cost of the  Building  containing  the
              Leased  Premises  and  which  shall  cover all  boilers,  pressure
              vessels, air conditioning  equipment and miscellaneous  electrical
              apparatus  owned by the  Landlord  and  which  shall  include  PCB
              coverage. It shall also include "Rental income" for the full gross
              annual income  equivalent  to I.A.O.  Profits Form No. 551 with an
              eighteen  (18) month  indemnity  period.  This policy  should also
              provide "Building By-Laws Endorsements";

       (iv)   "General  LiabIlity  Insurance" on a Comprehensive  Form and on an
              "occurrence"  basis without  deductible with retroactive  coverage
              against  claims for  Personal  and Bodily  Injury and Death and/or
              Property  Damage  occurring upon or about the Leased  Premises and
              for  a  limit  no  less  than  $5,000,000.00   inclusive  for  one
              occurrence; and

       (v)    such other insurance coverage or coverages as a prudent owner of a
              first

<PAGE>

                                      -18-

              class office building would obtain for protection  respecting loss
              of, or damage to the Building,  the Lands or the Leased  Premises,
              or liability arising therefrom.

       All  such  insurance  coverages  shall  be  kept  and  maintained  by the
       Landlord,  and in no event  shall the  coverage  be less than the  amount
       required by any  institution  then holding a mortgage on the Building and
       Common Area Facilities.  The Tenant shall pay to the Landlord, as part of
       Operating Costs, its Proportionate Share of the Landlord's insurance. The
       Tenant  shall  not do or  permit  to be  done  any act or  thing  whereby
       insurance  coverage,  premiums or any of them hereinbefore  contemplated,
       may be increased or  cancelled  by the  insurer,  or the Leased  Premises
       shall  be  rendered  uninsurable,  and if by  reason  of any act  done or
       permitted  or  omission,  as the case  may be,  by the  Tenant,  the said
       insurance coverage,  premiums or any of them shall be increased, then the
       Tenant,  if it  shall  fail  to  rectify  the  event  giving  rise to the
       increased  premium after written notice thereof from the Landlord,  shall
       be liable to pay all of such  increase  in premium,  with  respect to the
       entire coverages,  and this notwithstanding that the Tenant occupies only
       a portion of the Building covered by such insurance coverages, and if the
       Leased Premises shall be rendered  uninsurable,  or if the said insurance
       coverages,  or any of them,  shall be  cancelled  by reason of any act or
       omission as the case may be by the Tenant and shall not be susceptible of
       being  replaced,  after  the  Landlord's  reasonable  efforts  under  the
       circumstances  to do so, then the  Landlord,  after  giving the Tenant at
       least fourteen (14) days written notice within which to replace insurance
       coverage or coverages shall, at its absolute  discretion,  have the right
       to  determine  that the term  hereof  has  expired  and in such event the
       Tenant shall deliver up possession of the Leased  Premises as if the Term
       of this Lease had expired.

       PROVIDED that  no  act  required to be done by the Tenant nor any payment
       required to be made by the Tenant,  including reimbursements of insurance
       premiums  paid  by the  Landlord,  shall  relieve  the  Tenant  from  any
       liability  for damage  incurred  by the  Landlord as result of any act or
       omission of the Tenant.

       If any  other  tenant  of the  Building  has his own  insurance  premiums
       increased  by his  insurers as a result of the use or  occupation  by the
       Tenant herein of the within  Leased  Premises,  the Tenant  covenants and
       agrees  with  the  Landlord  after  written  notice  thereof,  to pay the
       additional cost forthwith upon demand as Additional Rent.

       The Landlord's  insurance policy shall contain a waiver of subrogation in
       favour of the Tenant or those for whom the Tenant is in law responsible.

 9.2   Agents. The Tenant  acknowledges,  covenants and agrees that every right,
       exemption  from  liability,  defense and  immunity of  whatsoever  nature
       applicable to the Landlord or to which the Landlord is entitled hereunder
       shall also be available  and shall extend to protect  every such agent of
       the  Landlord  acting  (in  the  course  of or  in  connection  with  his
       employment  or  otherwise)  and for the purposes of all of the  foregoing
       provisions  of this  clause,  the  Landlord  is or shall be  deemed to be
       acting as agent or  trustee  on behalf of and for the  benefit of persons
       who are or might be his servants, employees or agents from time to time.

 9.3   Tenant's  Insurance.  The Tenant  covenants to insure and to keep insured
       during the whole of the Term,  with an insurance  company or companies in
       good  standing  and upon terms and  conditions  all  satisfactory  to the
       Landlord:

       (i)    "All-Risks" insurance upon all property owned by the Tenant or for
              which it is legally liable or installed or affixed by or on behalf
              of the  Tenant and which is  located  in the  Building  including,
              without   limitation,    furniture,    fittings,    installations,
              alterations, additions, partitions and fixtures or anything in the
              nature  of a  Leasehold  Improvement  made or  installed  by or on
              behalf of the  Tenant in an amount  equal to the full  replacement
              cost thereof; if there is a

<PAGE>

                                      -19-

              dispute as to the amount which comprises full replacement cost the
              decision of the Landlord's Architect shall be conclusive;

       (ii)   all parties  hereto on a Comprehensive  Form for bodily injury and
              property  damage,  general  liability  coverage arising out of the
              use,  maintenance  or repair of the  Leased  Premises  and/or  the
              business of the Tenant or any subtenant, licensees or occupiers of
              the Leased  Premises;  such insurance  shall be for a limit of not
              less than $2,000,000.00 inclusive for any one occurrence,  or such
              higher limits as the Landlord, acting reasonably, or any mortgagee
              requires from time to time,  and shall contain a  severability  of
              interest clause, and a cross liability clause;

       (iii)  glass coverage for the replacement of all glass broken, cracked or
              damaged in, on and about the Leased Premises; and

       (iv)   any other form of insurance that the Landlord or any mortgagee may
              reasonably  require,  from time to time in form,  amounts  and for
              insurance risks acceptable to the Landlord and any mortgagee.

       The Tenant  covenants and agrees to provide the Landlord with evidence of
       insurance as required under this provision. Such evidence shall be by way
       of a  certified  copy of the  policy if  available  in timely  fashion or
       failing  which a  certificate  of insurance at such  time or times as the
       Landlord may require.  The Tenant  agrees to provide same to the Landlord
       forthwith  after  notice has been given by the  Landlord to the Tenant of
       its request. The Tenant's policy shall contain a waiver of subrogation in
       favour  of the  Landlord  and  those  for  whom  the  Landlord  is in law
       responsible.

 9.4   Limitation of Landlord's Liability. The Tenant agrees that:

       (i)    save and except for any injury,  loss, damages,  costs or expenses
              arising as a result of the negligence of the Landlord or those for
              whom the Landlord is in law responsible, the Landlord shall not be
              liable for any bodily injury or death of, or loss or damage to any
              property  belonging to the Tenant or its employees,  invitees,  or
              licensees  or any other  person in, on or about the  Building  and
              Common Area Facilities howsoever occurring and save and except for
              any injury,  loss, damages,  costs or expenses arising as a result
              of the  negligence  of the Landlord or those for whom the Landlord
              is in law  responsible,  in no event shall the  Landlord be liable
              for:

              (1)    any damage  which is caused by steam,  water,  rain or snow
                     which  may leak  into,  issue or flow from any part of the
                     Building  or Common  Area  Facilities  or from the pipes or
                     plumbing  works  thereof or from any other place or quarter
                     or  for  any  damage  caused  by  or  attributable  to  the
                     condition or arrangement of any electric or other wiring or
                     for any damage  caused by  anything  done or omitted by any
                     other tenant;

              (2)    any act or omission (including theft or malfeasance) on the
                     part of any agent,  contractor  or person from time to time
                     employed  by  it  to  perform  janitor  services,  security
                     services, maintenance,  supervision or any other work in or
                     about the Leased  Premises  or the  Building or Common Area
                     Facilities; and

              (3)    loss or  damage,  however  caused,  to  money,  securities,
                     negotiable  instruments,  papers or other  valuables of the
                     Tenant; and

       (ii)   save and except for any injury,  loss, damages,  costs or expenses
              arising as a result of the negligence of the Landlord or those for
              whom the Landlord is in law  responsible,  the Landlord shall have
              no  responsibility or liability for the failure to supply interior
              climate  control or elevator  service when prevented from doing so
              by strikes, the necessity of repairs, any order or regulation of

<PAGE>

                                      -20-

              any body  have  jurisdiction,  the  failure  of the  supply of any
              utility  required  for the  operation  thereof or any other  cause
              beyond the Landlord's  reasonable  control,  and shall not be held
              responsible  for any bodily  injury,  death or damage to  property
              arising  from  the use  of,  or any  happening  in or  about,  any
              elevator.

              Respecting  any negligent act referred to in this Section 9.4, the
              Landlord's liability shall be limited to the amount of proceeds of
              insurance  it has  received  in  respect  thereto  or  would  have
              received if it had  maintained  insurance  as required  under this
              Lease.

 9.5   Indemnity of Landlord.  The Tenant  agrees to indemnify and save harmless
       the  Landlord  in  respect  of all  claims  for  bodily  injury or death,
       property  damage or other loss or damage  arising from the conduct of any
       work by or any act or omission of the Tenant or any assignee,  subtenant,
       agent,  employee,  contractor,  invitee or licensee of the Tenant, and in
       respect of all costs,  expenses and liabilities  incurred by the Landlord
       in  connection  with or arising  out of all such  claims,  including  the
       expenses of any action or proceeding  pertaining thereto,  and in respect
       of any loss, cost, expense or damage suffered or incurred by the Landlord
       arising  from  any  breach  by the  Tenant  of any of its  covenants  and
       obligations under this Lease.

ARTICLE 10.00 - SUBORDINATION,  ATTORNMENT AND CERTIFICATES

 10.1  Subordination  and Attornment.  The Tenant agrees that this Lease and all
       the rights of the Tenant  hereunder  are subject and  subordinate  to all
       mortgages  now or hereafter  existing  (including  deeds of trust and all
       instruments  supplemental  thereto) which may now or hereafter affect the
       Building or Common Area  Facilities  and to all renewals,  modifications,
       consolidations,  replacements and extensions  thereof,  provided that the
       Tenant whenever requested by any mortgagee (including any trustee under a
       deed of trust and mortgage)  shall attorn to such mortgagee as the Tenant
       upon all the terms of this Lease.  Subject to the  foregoing,  the Tenant
       agrees to execute promptly whenever  requested by the Landlord or by such
       mortgagee such instrument of subordination or attornment, as the case may
       be, as may be  required  of it. At the  Tenant's  cost and  request,  the
       Landlord  will  use  its  reasonable   commercial  efforts  to  obtain  a
       non-disturbance agreement from existing or future encumbrancers.

 10.2  Certificates.  The  Tenant  shall  promptly  whenever  requested  by  the
       Landlord  from time to time execute and deliver to the  Landlord  (and if
       required by the Landlord, to any mortgagee [including any trustee under a
       deed of trust and mortgage]  designated by the Landlord) a certificate in
       writing as to the then status of this Lease,  including  as to whether it
       is in full force and effect,  is modified or  unmodified,  confirming the
       rent payable hereunder and the state of the accounts between the Landlord
       and Tenant,  the existence or  non-existence  of defaults,  and any other
       matters pertaining to this Lease as to which the Landlord shall request a
       certificate.

ARTICLE 11.00 - EVENTS OF DEFAULT AND REMEDIES

11.1   Events of Default and Remedies.  In the event of the happening of any one
       of the following events (hereinafter referred to as a "Default"):

       (a)    the Tenant shall have failed to pay an  instalment of Base Rental
              or of Additional  Rent or any other amount payable  hereunder when
              due and such default shall be continuing for a period of more than
              two (2) days after written notice by the Landlord to the Tenant of
              the amount due;

<PAGE>
                                      -21-

       (b)    there  shall  be a  default  of or with any  condition,  covenant,
              agreement  or other  obligation  on the part of the  Tenant  to be
              kept,  observed or performed  hereunder (other than the obligation
              to pay Base Rental,  Additional Rent or any other amount of money)
              and such Default shall be continuing for a period of more than ten
              (10) days  after  written  notice by the  Landlord  to the  Tenant
              specifying the Default and requiring that it discontinue;

       (c)    if any policy of  insurance  upon the Building or any part thereof
              from time to time  affected by the Landlord  shall be cancelled or
              about to be  cancelled  by the  insurer  by  reason  of the use or
              occupation  of the Leased  Premises by the Tenant or any assignee,
              sub-tenant  or licensee of the Tenant or anyone  permitted  by the
              Tenant  to be upon  the  Leased  Premises  and the  Tenant,  after
              receipt of notice in writing from the Landlord,  shall have failed
              to take such immediate  steps in respect of such use or occupation
              as shall enable the  Landlord to  reinstate or avoid  cancellation
              (as the case may be) of such policy of insurance;

       (d)    the Leased  Premises  shall,  without the prior written consent of
              the Landlord,  be used by any other persons than the Tenant or its
              permitted  assigns or  sub-tenants  or for any purpose  other than
              that for which  they were  leased or  occupied  or by any  persons
              whose occupancy is prohibited by this Lease;

       (e)    the  Leased  Premises  shall be vacated  or  abandoned,  or remain
              unoccupied,  without the prior written consent of the Landlord for
              seven  (7)  consecutive  days  or  more  while  capable  of  being
              occupied;

       (f)    the  balance  of the Term of this  Lease or any of the  goods  and
              chattels of the Tenant  located in the Leased  Premises,  shall at
              any time be seized in execution or attachment; or

       (g)    the Tenant shall make any  assignment for the benefit of creditors
              or become bankrupt or insolvent or take the benefit of any statute
              for bankrupt or insolvent debtors or, if a corporation, shall take
              any steps or suffer  any  order to be made for its  winding-up  or
              other  termination  of  its  corporate  existence;  or a  trustee,
              receiver or  receiver-manager  or agent or other like person shall
              be appointed of any of the assets of the Tenant;

       the Landlord  shall have the  following  rights and remedies all of which
       are cumulative and not  alternative and not to the exclusion of any other
       or  additional  rights and  remedies  in law or equity  available  to the
       Landlord by statute or otherwise:

       (i)    to remedy or attempt to remedy any Default of the  Tenant,  and in
              so doing  to make any  payments  due or  alleged  to be due by the
              Tenant to third  parties and to enter upon the Leased  Premises to
              do any  work  or  other  things  therein,  and in such  event  all
              reasonable  expenses of the Landlord in remedying or attempting to
              remedy such Default shall be payable by the Tenant to the Landlord
              on demand;

       (ii)   with respect to unpaid  overdue Rent, to the payment by the Tenant
              of the Rent and of interest  (which said interest  shall be deemed
              included  herein in the term  "Rent")  thereon at a rate per annum
              equal to three percent (3%) above the prime  commercial  loan rate
              charged to borrowers having the highest credit rating from time to
              time by the Landlord's principal bank from the date upon which the
              same was due until actual  payment  thereof and the maximum amount
              allowed under the laws of the  jurisdiction  in which the Building
              is located;

       (iii)  to  terminate  this Lease  forthwith  by  leaving  upon the Leased
              Premises or by

<PAGE>

                                      -22-

              affixing  to an  entrance  door  to  the  Leased  Premises  notice
              terminating  the  Lease  and to  immediately  thereafter  cease to
              furnish any services  hereunder and enter into and upon the Leased
              Premises or any part thereof in the name of the whole and the same
              to have  again,  repossess  and  enjoy  as of its  former  estate,
              anything in this Lease contained to the contrary  notwithstanding;
              and

       (iv)   to enter the  Leased  Premises  as agent of the Tenant and as such
              agent to re-let them and to receive the rent  therefor  and as the
              agent of the Tenant to take  possession  of any furniture or other
              property  thereon and upon giving ten (10) days' written notice to
              the Tenant to store the same at the expense and risk of the Tenant
              or to sell or  otherwise  dispose of the same at public or private
              sale without further notice and to apply the proceeds  thereof and
              any rent  derived from  re-letting  the Leased  Premises  upon the
              account of the Rent due and to become due under this Lease and the
              Tenant shall be liable to the Landlord for the deficiency if any.

11.2   Payment of Rent, etc. on Termination.

       (a)    Upon the giving by the Landlord of a notice in writing terminating
              this Lease under sub-paragraph 11.1 (iii) of this paragraph,  this
              Lease and the term shall  terminate,  Rent and any other  payments
              for which the Tenant is liable under this Lease shall be computed,
              apportioned  and  paid  in full  to the  date of such  termination
              forthwith,  and there  shall  immediately  become due and  payable
              forthwith in one lump sum, the next immediately  ensuing three (3)
              months'  Rent  (calculated  as if full Base Rental and  Additional
              Rent are owing and not giving credit for any  scheduled  free Rent
              period).  Upon  termination of this Lease and the Term, the Tenant
              shall immediately  deliver up possession of the Leased Premises to
              the Landlord, without compensation to the Tenant, and the Landlord
              may forthwith re-enter and take possession of them.

       (b)    The Tenant  shall pay to the  Landlord  on demand  all  reasonable
              costs  and  expenses,   including  reasonable  lawyers'  fees  and
              disbursements  incurred by the  Landlord in  enforcing  any of the
              obligations of the Tenant under this Lease.

       (c)    The Tenant shall pay to the  Landlord,  for any monetary  Default,
              interest  at a fixed rate per annum  equal to the most  favourable
              rate which the Landlord's  principal bank will lend money on prime
              loans to commercial  customers at the date when interest commences
              to run plus three percent (3%) per annum.  Such interest shall run
              from the due date of such sum  without the  necessity  of a demand
              until payment and shall be compounded semi-annually.

11.3   Renunciation.  The Tenant waives and renounces the benefit of any present
       or  future  statute  taking  away or  limiting  the  Landlord's  right of
       distress.

ARTICLE 12.00 - MISCELLANEOUS

12.1   Registration.  The Tenant  agrees with the Landlord not to register  this
       Lease,  but  nevertheless  if the Tenant  desires to register a notice of
       this Lease,  the Landlord agrees to execute a notice or  acknowledgement,
       if required,  sufficient for the purpose in such form as the Landlord and
       Tenant mutually  approve  provided in no event shall rental rates of this
       Lease be shown.

12.2   Notice.  Any notice  required or  contemplated  by any  provision of this
       Lease shall be given in writing, and if to the Landlord, either delivered
       to an executive officer of

<PAGE>

                                      -23-

       the Landlord or by facsimile transmission or mailed by prepaid registered
       mail addressed to the Landlord at 3650 Victoria Park Avenue,  Suite #500,
       North York  (Toronto),  Ontario,  M2H 3P7,  and if to the Tenant,  either
       delivered  to the Tenant (or to an officer of the Tenant if the Tenant is
       a firm or corporation) or by facsimile  transmission or mailed by prepaid
       registered  mail  addressed to the Tenant at the Leased  Premises.  Every
       such  notice  shall be deemed to have been  given when  delivered  or, if
       mailed as  aforesaid  in  Canada,  upon the day when it was  mailed.  The
       Landlord  may  from  time to time by  notice  in  writing  to the  Tenant
       designate  another  address in Canada as the address to which notices are
       to be mailed to it.

12.3   Extraneous  Agreements.   The  Tenant  acknowledges  that  there  are  no
       covenants,   representations,   warranties,   agreements   or  conditions
       expressed or implied  relating to this Lease or the Leased  Premises save
       as  expressly  set out in this  Lease  and in any  agreement  to Lease in
       writing  between the Landlord and the Tenant pursuant to which this Lease
       has been executed.  This Lease may not be modified except by an agreement
       in writing executed by the Landlord and the Tenant.

12.4   Construction.  All of the provisions of this Lease are to be construed as
       covenants  and  agreements.  If any provision of this Lease is illegal or
       unenforceable  it shall be  considered  separate and  severable  from the
       remaining  provisions  of this Lease,  which shall remain in force and be
       binding  as though  the said  provision  had  never  been  included.  The
       headings and marginal  sub-headings  of clauses and  sub-clauses  are for
       convenience  of  reference  and are not  intended  to limit,  enlarge  or
       otherwise affect their meanings.

12.5   Non-Waiver. No condoning,  excusing or overlooking by the Landlord or the
       Tenant of any  default,  breach or  non-observance  by the  Tenant or the
       Landlord,  as the case may be,  at any  time or times in  respect  of any
       covenant,  agreement, proviso or condition herein contained shall operate
       as a waiver of the Landlord's or the Tenant's rights hereunder in respect
       of any continuing or subsequent  default,  breach or non-observance or so
       as to  defeat or affect  in any way the  rights  of the  Landlord  or the
       Tenant in respect of any such continuing or subsequent  default or breach
       and no waiver shall be inferred or implied by anything done or omitted by
       the Landlord or the Tenant save only express waiver in writing.

12.6   Accord  and  Satisfaction.  No  payment  by the  Tenant or receipt by the
       Landlord of a lesser amount than the Base Rental and Additional Rent from
       time to time due  shall be  deemed  to be other  than on  account  of the
       earliest  stipulated  Base Rental and Additional  Rent due, nor shall any
       endorsement  or  statement on any cheque or any letter  accompanying  any
       cheque or payment of Base Rental or  Additional  Rent be deemed an accord
       and  satisfaction,  and the  Landlord  may accept  such cheque or payment
       without  prejudice to the Landlord's right to recover the balance of such
       Base Rental or  Additional  Rent or pursue any other  remedy  provided in
       this Lease.

12.7   Governing  Law.  This  Lease  shall  be  governed  by  and  construed  in
       accordance with the laws of the Province of Ontario.

12.8   Time of the Essence. Time shall be of the essence of this Lease and every
       part hereof.

12.9   No Partnership.  Nothing contained herein shall be deemed or construed by
       the parties hereto,  nor any third party, as creating the relationship of
       principal and agent,  or a  partnership,  or a joint venture  between the
       parties  hereto,  it  being  understood  and  agreed  that  none  of  the
       provisions  contained  herein nor any acts of the parties hereto shall be
       deemed to create any  relationship  between the parties hereto other than
       the relationship of Landlord and Tenant.

12.10  Force Majeure.  Except as herein  otherwise  expressly  provided,  if and
       whenever

<PAGE>

                                      -24-

       and to the  extent  that the  Landlord  shall be  prevented,  delayed  or
       restricted in the  fulfilment  of any  obligations  hereunder  other than
       because of a lack of financial resources on the part of the Landlord,  in
       respect of the supply or provision of any service or utility,  the making
       of any  repair,  the doing of any  work or any  other  thing by reason of
       strikes  or work  stoppages  or being  unable  to  obtain  any  material,
       service,  utility or labour  required  to fulfill such  obligation  or by
       reason of any statute,  law or  regulation  of or inability to obtain any
       permission from any  governmental  authority  having lawful  jurisdiction
       preventing,  delaying or  restricting  such  fulfilment,  or by reason of
       other unavoidable  occurrence,  other than because of a lack of financial
       resources on the part of the  Landlord,  the time for  fulfilment of such
       obligation shall be extended during the period in which such circumstance
       operates to prevent,  delay or restrict  the  fulfilment  thereof and the
       Tenant  shall not be  entitled  to  compensation  for any  inconvenience,
       nuisance or discomfort thereby occasioned.

12.11  Contra  Proferentem.  The Parties acknowledge and agree that both parties
       have  participated  in the  drafting of this  Lease,  and any rule of law
       providing that ambiguities shall be construed against the drafting party,
       shall be of no force or effect.

12.12  Planning Act. This Lease is expressly  conditional  upon  compliance with
       the land division  provisions of the Planning Act R.S.O.  1990 (as it may
       be amended from time to time), if applicable.

12.13  Access.  The Tenant,  its  employees,  invitees and customers and persons
       connected with the Tenant  (subject and except as in this Lease provided)
       shall have the right in common with others entitled  thereto from time to
       time to use the parking areas, driveways, walkways, lawns, ramps (if any)
       and other Common Areas in and about the Building  from time to time.  The
       Tenant shall not unreasonably block or in any manner hinder the Landlord,
       other tenants or other persons  claiming  through or under them or any of
       them who may be  authorized  by the  Landlord to utilize the Common Areas
       from so doing.  The Landlord may,  acting  reasonably,  from time to time
       permit the Tenant to have the  exclusive  use of  portions of the parking
       area which forms part of the Common Areas and to permit other  tenants or
       other persons to have exclusive use of portions thereof.

12.14  Transfers by the Landlord. The Landlord at any time and from time to time
       may sell,  transfer,  lease,  assign or otherwise dispose of the whole or
       any part of its  interest in the Leased  Premises or in the  Building and
       lands of which the Leased Premises form a part, at any time and from time
       to time,  may enter into any mortgage of the whole or any of its interest
       in the  Building  and  Lands  or in the  Leased  Premises.  If the  party
       acquiring  such  interest  shall have  agreed to assume and so long as it
       holds such interest,  to perform each of the covenants,  obligations  and
       agreements of the Landlord under this Lease in the same manner and to the
       same extent as if  originally  named as the  Landlord in this Lease,  the
       Landlord  shall,  thereupon  be released  from all of its  covenants  and
       obligations under this Lease.

       The  Landlord  may  assign  its  rights  under  this  Lease to a  lending
       institution as collateral security for a loan. If such assignment is made
       and  executed by the Landlord  and  notification  thereof is given to the
       Tenant by or on behalf of the Landlord  this Lease shall not be cancelled
       or modified for any reason whatsoever except as provided for by the terms
       hereof  or by  law  without  the  consent  in  writing  of  such  lending
       institution.

12.15  Occupancy Permit.  Provided further that notwithstanding the Commencement
       Date of the  Lease as  hereinbefore  set out,  the  Tenant  shall  not be
       permitted  to enter  into  possession  of the Leased  Premises  until the
       Tenant has obtained at its sole  expense,  an  occupancy  permit from the
       proper governmental authority. The Landlord, in its sole discretion,  may
       waive this provision. Provided further, the Tenant agrees to use its best
       efforts to obtain same prior to occupancy.

<PAGE>

                                      -25-

12.16  Leased  Premises.  Save and  except for any work to be  performed  by the
       Landlord as specifically set out herein,  the taking of possession of the
       Leased  Premises  by the Tenant  shall be  conclusive  evidence  that the
       Tenant  accepts the  Premises in an "as is"  condition  and that the said
       Leased  Premises  were in good  and  satisfactory  condition  at the time
       possession was so taken.

12.17  Successors and Assigns.  This Lease and everything herein contained shall
       enure to the benefit of and be binding upon the successors and assigns of
       the  Landlord  and the  permitted  successors  and assigns of the Tenant.
       References to the Tenant shall be read with such changes in gender as may
       be  appropriate,  depending upon whether the Tenant is a male or a female
       person  or a firm or  corporation,  and if the  Tenant  is more  than one
       person or entity,  the covenants of the Tenants shall be deemed joint and
       several.  All  obligations of the Tenant or the Landlord under this Lease
       shall be deemed to be  covenants  whether or not  expressed  as same.  No
       rights of the Tenant in this Lease  shall be deemed to be  personal,  but
       shall  accrue  to the  benefit  of  the  Tenant's  successors,  permitted
       subtenants and assigns.

12.18  Area Determination. In the event that any calculation or determination by
       the Landlord of the Rentable Area of any premises  (including  the Leased
       Premises)  or the  Building is  disputed  or called into  question by the
       Tenant, it shall be calculated or determined by the Landlord's  architect
       from time to time appointed for the purpose,  whose  certificate shall be
       conclusive and the cost of such certificate  shall be borne by the Tenant
       and the Landlord equally.

ARTICLE 13.00 - OTHER PROVISIONS

13.1   Common Areas. The Tenant acknowledges that the Common Area Facilities are
       at all times  subject  to the  exclusive  control  and  operation  of the
       Landlord,   and  the   Landlord   shall  have  the  right  to   construct
       improvements,  alterations  and  additions  thereto and to  relocate  the
       various facilities thereon.

13.2   Parking.  The Landlord shall provide the Tenant with surface parking at a
       ratio of four (4) stalls per 1,000  square feet of rentable  space leased
       during  the  initial  Term and any  subsequent  extension  terms  free of
       charge.  The Tenant further  acknowledges that the parking  facilities in
       the Common Area  Facilities are on a non-exclusive  "first come",  "first
       serve  basis"  and  may be  altered  or  diminished  during  the  term or
       extension  thereof  and the manner in which  access is  permitted  may be
       altered.

13.3   Window  Coverings.  The Tenant  acknowledges  that as at the date of this
       Lease the  Landlord  does not intend to require the Tenant to install and
       maintain window coverings. Provided however, that the Landlord shall have
       the right at any future time to  prescribe  a uniform  pattern for window
       coverings  to be  utilized  in the  Leased  Premises.  In the  event  the
       Landlord so  prescribes  same,  the Tenant  shall  permit the Landlord to
       install  window  coverings  at the cost of the  Tenant  which cost or the
       current  portion thereof shall form part of Operating  Costs.  Until such
       time,  no window  coverings  may be  installed  or utilized by the Tenant
       without  the  written  consent  of the  Landlord,  which  consent  may be
       unreasonably or arbitrarily withheld.

13.4   Extension.  Provided  that the Tenant is not  habitually in default under
       the terms of this Lease and the Tenant is not in material  default at the
       time of the exercise of the option herein,  then the Landlord  shall,  at
       the  expiration of the Term hereof,  upon written  request of the Tenant,
       grant to the Tenant an  extension  of this Lease for a further  period of
       five (5) years (the "Extension  Term") upon the same terms and conditions
       as  contained  herein,  save as to the Base Rental  rate,  save as to the
       Leasehold Improvement allowance,  save as to any Landlord's Work and save
       as to  any  further  right  of  extension  and in an  "as-is"  condition.
       Provided always that the

<PAGE>

                                      -26-

       Tenant  shall  have  given to the  Landlord  180 days'  notice in writing
       before the  expiration of the Term of its desire to have such  extension.
       The Base Rental rate for the Extension  Term shall be at the then current
       market rate for premises of comparable  type,  location and condition and
       as mutually agreed between the Landlord and the Tenant. In the event that
       the Landlord and the Tenant are unable to agree upon the Base Rental rate
       for the Extension Term by 120 days prior to the maturity date, the matter
       shall be submitted to  arbitration by notice given by either party to the
       other.  Upon such notice being given,  the dispute shall be determined by
       the award of 3 arbitrators,  or by a majority of them, one to be named by
       the Landlord  and one by the Tenant  within 30 days of the giving of such
       notice,  and the 3rd to be selected by these 2 arbitrators  within 7 days
       after  both have been  nominated.  If either the  Landlord  or the Tenant
       shall neglect or refuse to name its  arbitrator in the time  specified or
       to proceed with the arbitration,  the arbitrator named by the other party
       shall  proceed  with the  arbitration,  and the award of such  arbitrator
       shall  be final  and  binding  upon  the  Landlord  and the  Tenant.  The
       Arbitrators  shall have all the power  given by the  Arbitrations  Act of
       Ontario  and may at any time  proceed  in such  manner as they see fit on
       such notice as they deem  reasonable in the absence of either  party,  if
       such party fails to attend.  Each party shall pay its own costs and shall
       share equally the costs of arbitration.  The award and  determination  of
       the  arbitrators  shall be final and binding upon both parties hereto and
       each party agrees not to appeal any such award or determination.

       In no event shall the Base Rental for the Extension Term be less than the
       highest Base Rental payable under the original Term thereof.

       If the award of the arbitrators is not given before the commencement date
       of the Extension  Term, then the Tenant shall commence paying rent at the
       market rate as determined by the Landlord  together with Additional Rent,
       which shall be adjusted  forthwith after the award of the arbitrators has
       become final and binding,  to be calculated from the commencement date of
       the Extension Term.

       Interest at the rate set out herein  shall be  calculated  monthly on the
       difference  between  the Base  Rental  paid by the  Tenant and the actual
       amount awarded by the arbitrators and shall be paid forthwith upon demand
       when the arbitrators' decision has been made.

       The  extension  of lease form shall be  prepared  by the  Landlord at the
       Tenant's cost and the Tenant  covenants and agrees to pay to the Landlord
       said costs forthwith upon demand.

 13.5  Leasehold Improvement Allowance

       The Landlord shall provide and pay to the Tenant a leasehold  improvement
       allowance on or before the  Commencement  Date in the amount of $6.25 per
       rentable  square  foot plus G.S.T.  for the first  5,000  square feet and
       $26.25  per  rentable  square  foot plus  G.S.T.  for the  balance of the
       Premises (collectively the "Leasehold Improvement Allowance").

 13.6  Leasehold Improvements

       Any  Leasehold  Improvements  shall be completed by the Tenant at its own
       cost,   subject  to   approval   by  the   Landlord   of  all  plans  and
       specifications,  such  approval  not  to be  unreasonably  withheld.  The
       Landlord   shall  not   charge   any  fees  to  review   such  plans  and
       specifications save and except for reasonable out of pocket expenses.

       The Landlord shall act as General Contractor in completing the Leasehold

<PAGE>

                                      -27-

       Improvements.  The Landlord  shall ensure that all work be completed in a
       good and efficient manner and in compliance with all applicable  building
       and  fire  codes.   The  Landlord's  fee  for  completing  the  Leasehold
       Improvements  shall  not  exceed  8% of the  cost  of  construction.  The
       Landlord shall tender out all construction work to a minimum of three (3)
       subcontractors  and shall make  available  in writing to the Tenant  upon
       reasonable  request all costs,  fees,  and permits etc.  relating to such
       construction.  Further,  the Landlord shall deliver the completed  Leased
       Premises to the Tenant no later than December 15, 1999,  subject to Force
       Majeure and delay caused directly or indirectly by the Tenant.

 13.7  Base Building

       Subject to Force  Majeure and delay caused  directly or indirectly by the
       Tenant,  the Landlord at its sole cost and expense  shall ensure that all
       Base Building  items are  completed  prior to the  Commencement  Date, in
       accordance with the Development Schedule attached hereto as Schedule "E".
       Base  Building  shall  include,  but not  necessarily  be  limited to the
       exterior  walls  including  drywall  complete with skim coat painted with
       primer,  washroom,  stairs,  lobby,  common ground floor  service  rooms,
       electrical  distribution for lighting  purposes,  sprinkler drops to suit
       Tenant's final plan, fully  operational HVAC up to an including main high
       pressure line, all life safety systems in the Leased Premises, and sealed
       concrete floor.

       The Landlord shall also provide skylights in the Leased Premises in areas
       designated by the Tenant on plans  submitted to the Landlord,  subject to
       final approval of the Landlord.

       Further,  the Landlord will ensure that all of the above shall conform to
       all current building and fire codes, laws, rules and regulations.

       Attached hereto as Schedule "D", is a complete performance  specification
       outlining  the  construction  of the  Base  Building  and  what  is to be
       included as part of the Base Building.

 13.8  Signage

       The Landlord  will allow the Tenant at the Tenant's  sole cost to erect a
       ground level podium sign,  subject to all requisite  municipal  approvals
       and design, size and placement of said signage to be mutually agreed upon
       between the Landlord and the Tenant, both parties acting reasonably.

       The Landlord further agrees to use its best commercial  efforts,  subject
       to any rights granted to other tenants, and subject to municipal approval
       and at the  Tenant's  sole  cost,  to allow the  Tenant  exterior  fascia
       mounted corporate signage on the face of the Building,  the design,  size
       and placement of same to be mutually agreed upon between the Landlord and
       the Tenant, both acting reasonably.

       If any current northern  exterior fascia mounted  corporate  signage (the
       "Additional  Signage Lights") become available at any time from execution
       of this Lease and  throughout  the Term,  the  Landlord  will  notify the
       Tenant of such  availability  and the Tenant will have seven (7) business
       days from  receipt of  notification  to accept or decline the  Additional
       Signage Rights.

       In  addition,  the  Tenant at its sole cost shall have the right to erect
       exclusive  corporate signage on a Building podium with prominent exposure
       to Highway 401, in the Building directory,  and/or near the main entrance
       doors to the Leased Premises.  The design of such signage is to be agreed
       upon between the Landlord and the Tenant, both parties acting reasonably,
       and subject to compliance with municipal authorities.

<PAGE>

                                      -28-

13.9   Year 2000 Compliance

       The Landlord will ensure that any services it is personally  obligated to
       provide to the Tenant under the terms of this Lease which  involve or are
       dependent upon any computer  hardware or software or any other  automated
       equipment or devices  are, or will be by December  31,  1999,  millennium
       compliant  such that  there  will be no  interruption  of  service to the
       Tenant.  The  Tenant  acknowledges  that  the  Landlord  cannot  be  held
       responsible for provision of services or products beyond its control (eg.
       Hydro).

 13.10 24-Hour Access

       It is understood  and agreed that the Tenant,  its employees and invitees
       shall have the right,  subject to  emergencies,  and reasonable  security
       regulations,  twenty-four  (24)  hours  per day,  seven (7) days per week
       throughout  the Term and any  extension  term(s),  to have  access to the
       Premises  and parking  facilities  for the Building and to use the common
       areas of the  Building  and the  property  for its  intended  purposes in
       common with others entitled thereto. The foregoing access to the Premises
       shall include,  but not be limited to, continuous supply to the Tenant of
       electric power, hot and cold running water,  heating,  air  conditioning,
       lighting  within the Premises  and  elevator  services to the Premises as
       outlined in the Lease.

       The Tenant  acknowledges  that the Additional Rent estimates of Operating
       Costs and Utilities contained in this Lease are based on normal operating
       hours of 7:00 am to 6:00  p.m.,  Monday  to  Friday  (Statutory  Holidays
       excepted)  and that any after hours  access  will affect said  estimates.
       Tenant  agrees  to  provide  reasonable  notice to the  Landlord  when it
       requires after hours HVAC.

13.11  Riders

       The Riders attached form part of the within Lease.

IN WITNESS  WHEREOF the Landlord and Tenant have executed this Lease.

              AIRPORT  CORPORATE CENTRE OFFICE PARK INC.

              Per:         Name Illegible
                  --------------------------------------------
                 (I/We have authority to bind the Corporation)

              CERTICOM CORP.

              Per:        /s/ B. MacInnis
                  --------------------------------------------
                  (I/We have authority to bind the Corporation)

<PAGE>

                                  SCHEDULE "A"

Part of Block 5, Plan 43M-793, designated as Parts 3,4,5,8,9 and 10, on Plan 43R
-18324 City of Mississauga, in the Regional Municipality of Peel.

The Parties  acknowledge  that the above parcel contains lands in excess of that
required  for the Property and that this  schedule  will be replaced  with a new
schedule when a new reference plan is registered on title  delineating the lands
that are intended to comprise the subject Property.

<PAGE>

                                  SCHEDULE "B"

                        [ FOURTH FLOOR PLAN MAP OMITTED ]

<PAGE>
                                  SCHEDULE "C"

                              RULES AND REGULATIONS

The  Rules  and  Regulations  may  differentiate   between  different  types  of
businesses  in the  Building but the Rules and  Regulations  will be adopted and
promulgated  by the  Landlord  acting  reasonably  and in such manner as would a
prudent Landlord of a reasonably similar office building.  The Tenant's  failure
to keep and observe the Rules and Regulations  now or from time to time in force
constitutes  a  default  under  this  Lease in such  manner  as if the same were
contained herein as covenants. The Landlord reserves the right from time to time
to amend or  supplement  the  Rules and  Regulations  applicable  to the  Leased
Premises or the Building as in the Landlord's absolute and unfettered discretion
are  from  time to time  needed  for the  safety,  care,  cleanliness  and  more
efficient  operation  of the  Building  and for the  preservation  of good order
therein. Notice of the Rules and Regulations and amendments and supplements,  if
any, shall be given to the Tenant and the Tenant shall thereupon comply with and
observe all such Rules and  Regulations  provided  that no Rules and Regulations
shall  contradict any terms,  covenants and conditions of this Lease.  The Rules
and Regulations as at the Commencement Date are as follows:

1.     The Tenant shall not place any debris, garbage, trash or refuse or permit
       same to be placed or left in or upon any part of the Building  outside of
       the Leased Premises and the Tenant shall not allow any undue accumulation
       of any  debris,  garbage,  trash or refuse in or  outside  of the  Leased
       Premises.

2.     The Landlord  shall permit the Tenant and the Tenant's  employees and all
       Persons lawfully requiring communication with them to have the use during
       such  hours as the  Landlord  deems  reasonable  in  common  with  others
       entitled thereto of the main entrance and stairways, corridors, elevators
       or other mechanical  means of access leading to the Leased  Premises.  At
       times other than during such hours as the Landlord  deems  reasonable the
       Tenant and the  employees of the Tenant shall have access to the Building
       and to the  Leased  Premises  only  in  accordance  with  the  Rules  and
       Regulations and shall be required to satisfactorily  identify  themselves
       and to register in any book which may at the Landlord's option be kept by
       the Landlord for such purpose. If identification is not satisfactory, the
       Landlord is entitled to prevent the Tenant or the  Tenant's  employees or
       other  Persons  lawfully  requiring  communication  with the Tenant  from
       having access to the Building. In addition,  the Landlord is not required
       to open the door to the Leased  Premises  for the  purpose of  permitting
       entry therein to any Person not having a key to the Leased Premises.

3.     The Landlord  shall permit the Tenant and the  employees of the Tenant in
       common with others entitled thereto, to use the washrooms on the floor of
       the  Building  on which the  Leased  Premises  are  situated  or, in lieu
       thereof, those washrooms designated by the Landlord, save and except when
       the  general  water  supply may be turned off from the public  main or at
       such other times when repair and  maintenance  undertaken by the Landlord
       shall necessitate the non-use of the facilities.

4.     The Tenant  shall  permit  window  cleaners  to clean the  windows of the
       Leased Premises during such hours as the Landlord deems reasonable.

5.     The sidewalks, entrances, passages, elevators and staircases shall not be
       obstructed  or used by the  Tenant,  its agents,  servants,  contractors,
       invitees or  employees  for any purpose  other than ingress to and egress
       from the offices.  The Landlord  reserves  entire control of all parts of
       the Building employed for the

<PAGE>

                                       -2-

       common benefit of the tenants and without  restricting  the generality of
       the  foregoing,  the  sidewalks,  entrances,  corridors  and passages not
       within  the  Leased  Premises,  washrooms,  lavatories,  air-conditioning
       closets,  fan rooms,  janitor's  closets,  electrical  closets  and other
       closets,  stairs,  elevator shafts,  flues, stacks, pipe shafts and ducts
       and shall have the right to place such signs and appliances  therein,  as
       it deems  advisable,  provided that ingress to and egress from the Leased
       Premises is not unduly impaired thereby.

6.     The Tenant,  its agents,  servants,  contractors,  invitees or employees,
       shall not bring in or take out, position,  construct, install or move any
       safe,  business  machinery  or other  heavy  machinery  or  equipment  or
       anything  liable to injure or destroy  any part of the  Building  without
       first  obtaining the consent in writing of the  Landlord.  In giving such
       consent, the Landlord shall have the right in its absolute and unfettered
       discretion,  to prescribe the weight permitted and the position  thereof,
       and the use and design of planks,  skids or platforms,  to distribute the
       weight  thereof.  All damage done to the  Building by moving or using any
       such heavy  equipment  or other office  equipment  or furniture  shall be
       repaired at the expense of the Tenant.  The moving of all heavy equipment
       or  other  office  equipment  or  furniture  shall  occur  only by  prior
       arrangement  with the  Landlord.  No Tenant shall employ anyone to do its
       moving  in the  Building  other  than the staff of the  Building,  unless
       permission  to  employ  anyone  else is  given  by the  Landlord  and the
       reasonable  cost of such moving  shall be paid by the  Tenant.  Safes and
       other heavy office  equipment  and  machinery  shall be moved through the
       halls and corridors only upon steel bearing  plates.  No freight or bulky
       matter of any  description  will be received into the Building or carried
       in the elevators except during hours approved by the Landlord.

 7.    The  Tenant  shall not place or cause to be placed any  additional  locks
       upon  any  doors of the  Leased  Premises  without  the  approval  of the
       Landlord and subject to any conditions imposed by the Landlord.  Two keys
       shall be  supplied  to the  Tenant for each  entrance  door to the Leased
       Premises  and all  locks  shall  be  standard  to  permit  access  to the
       Landlord's  master key. If additional  keys are  requested,  they must be
       paid for by the Tenant. No one, other than the Landlord's staff will have
       keys to the outside entrance doors of the Building.

 8.    The water  closets  and other water  apparatus  shall not be used for any
       purpose  other  than  those  for  which  they  were  constructed,  and no
       sweepings,  rubbish,  rags,  ashes or other  substances  shall be  thrown
       therein. Any damage resulting from misuse shall be borne by the Tenant by
       whom or by whose agents,  servants,  or employees the same is caused. The
       Tenant  shall not (a) let the water run unless it is in actual  use,  (b)
       deface or mark any part of the Building,  (c) drive nails,  spikes, hooks
       or screws into the walls or woodwork of the Building,  or (d) bore, drill
       or cut into the walls or  woodwork  of the  Building in any manner or for
       any reason.

 9.    No  one  shall  use  the  Leased  Premises  for  sleeping  apartments  or
       residential  purposes, or for the storage of personal effects or articles
       other than those required for business purposes.

10.    The Tenant  shall not permit any  cooking or any  heating of any foods or
       liquids in the  Leased  Premises,*  without  the  written  consent of the
       Landlord.

11.    Canvassing,  soliciting  and peddling in or about the Building and in the
       parking facilities of the Building are prohibited.

12.    It shall be the duty of the  Tenant to  assist  and  co-operate  with the
       Landlord in preventing injury to the Leased Premises.

                  *other  than the heating of foods or liquids by  microwave  or
                  similar device as is normal and typical for office premises,

<PAGE>

                                       -3-

13.    No flammable  oils or other  flammable,  dangerous or explosive  material
       save those approved in writing by the  Landlord's  insurers shall be kept
       or permitted to be kept in the Leased Premises.

14.    No  bicycles  or other  vehicles  shall be brought  within  the  building
       without the consent of the Landlord.

15.    No  animals or birds  shall be  brought  into the  Building  without  the
       consent of the Landlord.

 16.   The Tenant  shall not  install or permit the  installation  or use of any
       machine  dispensing goods for sale in the Leased Premises or the Building
       or permit the  delivery of an food or  beverage to the Leased  Premises,*
       without  the  approval  of the  Landlord,**  or in  contravention  of any
       regulations fixed or to be fixed by the Landlord. Only Persons authorized
       by the Landlord  shall be permitted to deliver or to use the elevators in
       the  Building  for the purpose of  delivering  foods or  beverages to the
       Leased Premises.
                           * other than normal take-out food,
                           ** which approval shall not be unreasonably withheld,

 17.   If the Tenant desires telegraphic or telephonic connections, the Landlord
       will  direct  the  electricians  as to where  and how the wires are to be
       introduced.  No gas pipe or electric wire will be permitted which has not
       been ordered or authorized by the Landlord.

 18.   The Tenant shall not cover or obstruct any of the  skylights  and windows
       that reflect or admit light into any part of the Building  except for the
       proper use of approved window coverings.

 19.   Any hand trucks,  carryalls,  or similar  appliances used in the Building
       with the consent of the  Landlord,  shall be equipped  with rubber tires,
       slide guards and such other safeguards as the Landlord requires.

 20.   The Tenant shall not place or maintain any supplies, merchandise or other
       articles  in any  vestibule  or  entry  of the  Leased  Premises,  on the
       footwalks  adjacent  thereto or  elsewhere  on the exterior of the Leased
       Premises or the Building.

 21.   The Tenant shall not commit or suffer or permit to be committed any waste
       upon,  or damage  to, or  disfiguration  of the  Leased  Premises  or any
       nuisance or other act or thing which disturbs the quiet  enjoyment of any
       other tenant in the Building or which unreasonably disturbs or interferes
       with or annoys any Person, nor perform any acts or carry on any practices
       which may damage the building.

 22.   The Tenant  shall not refer to the  Building  by any name other than that
       designated  from time to time by the Landlord,  nor use such name for any
       purpose other than that of the business  address of the Tenant,  provided
       that the Tenant may use the municipal number of the Building  assigned to
       it by the Landlord instead of the name of the Building.

 23.   The  Tenant  shall  not  install  or allow  on the  Leased  Premises  any
       transmitting  device, nor erect any aerial on the roof of the Building or
       on any  exterior  walls of the Leased  Premises.  Any such  installations
       shall be subject to removal by the  Landlord  without  notice at any time
       and such removal  shall be done and all damage as a result  thereof shall
       be made  good,  in each  case,  at the  cost of the  Tenant,  payable  as
       Additional Rent forthwith on demand.

24.    The Tenant shall not use any  travelling  or flashing  lights or signs or
       any loudspeakers, television, phonographs, radio or other audio-visual or
       mechanical  devices in a manner so that they can be heard or seen outside
       of the Leased

<PAGE>

                                       -4-

       Premises.  If the Tenant uses any such  equipment  without  receiving the
       prior written consent of the Landlord,  the Landlord shall be entitled to
       remove such  equipment  without notice at any time and such removal shall
       be done and all damage as a result  thereof  shall be made good,  in each
       case, at the cost of the Tenant,  payable as Additional Rent forthwith on
       demand.

25.    The Landlord shall have the right to restrict access to the elevators for
       move-in and move-out  purposes.  The Tenant shall consult prior to taking
       or giving up  occupation  of the  Leased  Premises  in order to obtain an
       elevator schedule from the Landlord.

26.    If the Tenant  requires the supply of water,  electricity,  heating,  air
       conditioning  or any other  utility  or service  after the  normal  hours
       during which the Landlord  supplies same or on a weekend or holiday,  the
       Tenant shall purchase its  requirements  for those  utilities or services
       from the Landlord and the Tenant shall pay to the Landlord as  Additional
       Rent  forthwith  upon demand the cost of same at the rates  current  from
       time to time set by the Landlord.*

27.    There shall be no smoking  allowed in any part of the Building  including
       the Leased Premises and all public areas which shall include,  but not be
       limited to washrooms,  elevators, elevator lobbies, common area hallways,
       stairwells, etc.

       *  The Tenant  acknowledges  that in order for the Tenant to  requisition
          the supply of  utilities  after the hours that the  Landlord  normally
          supplies  same,  notice  will  have  to be  given  to  the  Landlord's
          representative at least one (1) hour prior to 5:00 p.m. Monday through
          Friday (excluding  Statutory  Holidays). The Tenant shall be obligated
          to give not less than one (1) hour's  notice  during such time periods
          and if  notice  is  given  outside  of such  time  periods  or  during
          Statutory  Holidays,   the  Tenant  shall  be  obligated  to  pay  any
          out-of-pocket  expenses which the Landlord  incurs in order to turn on
          the supply of utilities.

<PAGE>

                                  SCHEDULE "D"

                           5520 & 5560 EXPLORER DRIVE
                              MISSISSAUGA, ONTARIO
--------------------------------------------------------------------------------
                                 SPECIFICATION
                                  BASE BUILDING
--------------------------------------------------------------------------------
                                      INDEX
                                      -----

DESCRIPTION                                                              SECTION
-----------                                                              -------
GENERAL DESCRIPTION & CLARIFICATIONS ...................................    1
SITE WORK ..............................................................    2
CONCRETE ...............................................................    3
MASONRY ................................................................    4
METALS .................................................................    5
WOOD & PLASTIC .........................................................    6
THERMAL & MOISTURE PROTECTION ..........................................    7
DOORS& WINDOWS .........................................................    8
FINISHES ...............................................................    9
SPECIALTIES ............................................................   10
EQUIPMENT ..............................................................   11
FURNISHING AND FIXTURES ................................................   12
SPECIAL CONSTRUCTION ...................................................   13
CONVEYING SYSTEMS ......................................................   14
MECHANICAL .............................................................   15
ELECTRICAL .............................................................   16
TENANT IMPROVEMENTS ....................................................   17

<PAGE>

<TABLE>
<CAPTION>

BASE BUILDING SPECIFICATION                                               MENKES
--------------------------------------------------------------------------------
 PROJECT:     5520 & 5560 EXPLORER DRIVE, MISSISSAUGA, ONTARIO
                                                                  MARCH 30, 1999
--------------------------------------------------------------------------------

<S>                                <C>
 1.1   GENERAL DESCRIPTION

       i.    OFFICE:               o  25,000 sq. ft. (approx,) per floor times 4 floors
                                   o  9 ft. clear to ceiling, all floors
                                   o  10 ft. clear to ceiling, ground floor lobby
                                   o  Smooth, white precast concrete and reflective
                                      glass facade
                                   o  30ft. x 30ft. bays

       ii.   GFA:                  o  100,000 sq. ft.

       iii.  SITE:                 o  Fully landscaped including all service connections.
                                   o  4 car per 1,000 sq.ft. rentable

       iv.   OCCUPANCY:            o  Group "D"
                                   o  Based  on  the  Ontario   Building   Code,
                                      current revision.

       v.    SCOPE OF WORK:        o  All materials, labour, Building Permits, Fees &
                                      Deposits, Occupancy Permit, applicable taxes,
                                      design costs, inspection and testing costs.
                                   o  GST is additional  to any quoted;  purchase
                                      prices,  optional costs, unit rates,  lease
                                      rates, etc.

 1.2   GENERAL CLARIFICATIONS

       i.    DESIGN:               Shall comply with the requirements of  the local
                                   Municipal Building Codes and By-Laws in effect at
                                   date of the execution of the contract, including
                                   ASHRAE 90.1
</TABLE>

                                       -1-

<PAGE>

<TABLE>
<CAPTION>

BASE BUILDING SPECIFICATION                                               MENKES
--------------------------------------------------------------------------------
 PROJECT:     5520 & 5560 EXPLORER DRIVE, MISSISSAUGA, ONTARIO
                                                                  MARCH 30, 1999
--------------------------------------------------------------------------------

<S>                                <C>
       ii.   ENGINEERING:          All of the architectural and professional engineering
                                   fees for the complete design and supervision of the
                                   facilities, including but not limited to:
                                   o  Geotechnical
                                   o  Quality control
                                   o  Architectural
                                   o  Structural
                                   o  Mechanical
                                   o  Electrical
                                   o  Sprinkler Protection
                                   o  Landscape

       iii.  WORK EXCLUDED:        (Tenant supplied items)
                                   o  Communication systems
                                   o  Data networks
                                   o  Special floor loading (not specified)
                                   o  Process  services  and/or  equipment  (not specified)
                                   o  Security systems
                                   o  Department of Labour Approval
                                   o  Furniture and furnishings

       iv.   WORKMANSHIP           o  Materials used shall be new and free from
             & GUARANTEES:            defects.
                                   o  All work shall meet industry standards for
                                      detail and quality.
                                   o  All  workmanship  and material  guaranteed
                                      for a period of one (1) year from the date
                                      of substantial completion.

2 SITE WORK

                                   Excavation and backfill for foundations.

                                   Complete   underground  storm  drain  system,
                                   sanitary sewer system,  domestic water system
                                   and natural gas connection.
</TABLE>

                                      -2-

<PAGE>

<TABLE>
<CAPTION>

BASE BUILDING SPECIFICATION                                               MENKES
--------------------------------------------------------------------------------
 PROJECT:     5520 & 5560 EXPLORER DRIVE, MISSISSAUGA, ONTARIO
                                                                  MARCH 30, 1999
--------------------------------------------------------------------------------

<S>                                <C>
                                   Municipal water and sewer connection  charges
                                   included.

                                   Firemain and yard hydrants to meet applicable
                                   fire code.

                                   Landscaping (trees, shrubs, pavers for patio, design,
                                   borders, etc.) included  to Municipal standards.

                                   No.1 grade sod for front yard. Three (3) inch of
                                   topsoil throughout.

                                   Irrigation system for landscaped areas.

                                   Heavy duty asphalt throughout trucking areas.

                                   Concrete curbs, sidewalks and curb cuts.

3            CONCRETE

                                   Foundation to suit site conditions.

                                   48  inch   (Forty-Eight)   high   formed  and
                                   poured-in    place,    reinforced    concrete
                                   dockwall.

                                   Office Floors:

                                   o  4 inch slab on grade  with one coat of cure
                                      and  seal  on  ground   floor

                                   o  reinforced concrete,  poured  in  place  for all  floors
                                      above grade to accommodate a live load of 100 psf.
                                      (including 20 lb. partition load)

                                   Minimum under slab granular fill materials to be 8"

                                   Poured  in  place  elevator  shaft  and  core walls.

                                   Precast concrete stairs.

                                   Uninsulated   concrete   panels   for  office fascia.
</TABLE>

                                       -3-

<PAGE>

<TABLE>
<CAPTION>

BASE BUILDING SPECIFICATION                                               MENKES
--------------------------------------------------------------------------------
 PROJECT:     5520 & 5560 EXPLORER DRIVE, MISSISSAUGA, ONTARIO
                                                                  MARCH 30, 1999
--------------------------------------------------------------------------------

<S>                                <C>
4            MASONRY

                                   o  block wall for service areas

5            METALS

       i.    STRUCTURAL STEEL:     Framing to roof screen(s).

                                   Fabrication   and  erection  to  comply  with
                                   C.S.A.  Specifications  S-16 and inspected by
                                   an independent company.

                                   Structural steel to received one shop coat of
                                   red oxide primer.

       ii.   MISCELLANEOUS:        o  stair handrails

       iii.  METAL SIDING:         o  26 gauge flat metal siding to roof screen painted
                                      to match windows.
                                   o  26 GA coloured roof flashings.
6            WOOD & PLASTIC
                                   Washroom vanities.

7            THERMAL AND MOISTURE PROTECTION

       i.    ROOFING:              Built-up with vapour barrier, 4 ply asphalt and gravel.
                                   FM Class 1 materials, I60 rating.

                                   Installation inspected by independent company.

       ii.   INSULATION            To meet ASHRAE 90.1 energy standards.

                                                      Insulation Value
                                                      ----------------
                                   Walls                  R12
                                   Roof                   R20
</TABLE>

                                       -4-

<PAGE>

<TABLE>
<CAPTION>

BASE BUILDING SPECIFICATION                                               MENKES
--------------------------------------------------------------------------------
 PROJECT:     5520 & 5560 EXPLORER DRIVE, MISSISSAUGA, ONTARIO
                                                                  MARCH 30, 1999
--------------------------------------------------------------------------------

<S>                                <C>
8            DOORS AND WINDOWS

       i.    METAL DOORS           Insulated hollow metal doors in hollow metal frames
             AND FRAMES            (HMPS) on exterior to code (in numbers and location).

                                   Uninsulated HMPS for interior of Service Rooms,
                                   washrooms and stairs.

       ii.   OVERHEAD DOORS:       1 total 8' x 10' steel, insulated, manually operated,
                                   truck-level doors.

       iii.  GLAZING:              Office glazing to be thermally broken clear anodized
                                   frames with double  sealed units (clear glass
                                   inside, reflective outside).

                                   Full height mirrors over vanities.

9            FINISHES

       i.    OFFICE:               Painted insulated drywall on 3 5/8" studs, full height
                                   for perimeter walls, lobby.

                                   1/2 inch painted drywall on 3 5/8" metal studs with
                                   sound insulation, full height for washrooms.

                                   20" x 60" acoustic ceiling at 9 ft height.

       ii.   PAINTING:             3 coats latex on: all misc, steel, stairs, washrooms,
                                   overhead doors, epoxy drywall.

       iii.  FLOORING:             Ceramic washrooms, granite/quarry lobby.
</TABLE>

                                      -5-

<PAGE>

<TABLE>
<CAPTION>

BASE BUILDING SPECIFICATION                                               MENKES
--------------------------------------------------------------------------------
 PROJECT:     5520 & 5560 EXPLORER DRIVE, MISSISSAUGA, ONTARIO
                                                                  MARCH 30, 1999
--------------------------------------------------------------------------------

<S>                                <C>
10           SPECIALTIES

       i.    WASHROOM              Plastic laminate ceiling mounted partitions for each
             PARTITIONS:           stall.

       ii.   WASHROOM              Double toilet paper dispensers in each stall.
             ACCESSORIES:

                                   Recessed  combination paper towel dispenser /
                                   disposal in each washroom.

                                   Surface mount soap dispenser for each basin.

                                   Sanitary   napkin  disposal  in  each  female
                                   washroom stall.

 11    EQUIPMENT

       i.    DOCK PACKAGE:         Dock bumpers, dock levelers (27,000 lb., 6 ft. x 6 ft.
                                   platform, mechanically operated).

       ii.   PROCESS:              Excluded are Client supplied process items such as:
                                   kitchen, cafeteria, water treatment, refrigeration, air
                                   filters, dust collection, waste collection, compaction
                                   equipment, cranes, make up air and exhaust, etc.

12           FURNISHINGS AND FIXTURES

                                   Excluded

13           SPECIAL CONSTRUCTION

                                   Excluded
</TABLE>

                                      -6-

<PAGE>

<TABLE>
<CAPTION>

BASE BUILDING SPECIFICATION                                               MENKES
--------------------------------------------------------------------------------
 PROJECT:     5520 & 5560 EXPLORER DRIVE, MISSISSAUGA, ONTARIO
                                                                  MARCH 30, 1999
--------------------------------------------------------------------------------
<S>                                <C>
14           CONVEYING SYSTEMS
                                   3 total, 150 fpm. hydraulic elevators, 3000 lb. one 10
                                   ft. cab for freight.

                                   Granite/quarry flooring to match lobby.

 15          MECHANICAL

       i.    PLUMBING:             Complete plumbing system with wall hung fixtures for
                                   eight washrooms as follows:

                                                Gr. Floor             2nd Floor
                                                ---------             ---------
                                                M      F              M     F

                                   Water        2      4              3     5
                                   closets
                                   Urinal       2     --              3     --
                                   Basin        6      4              4      5
                                                (vanity)              (Vanity)

       ii.   FIRE PROTECTION:      Light hazard including fire hose cabinet.

                                   Excluded are: loop main, smoke vents,  foam, chemical
                                   or CO(2) systems.

       iii.  HEATING AND           All finished office areas are to be heated by gas fired,
             AIR-CONDITIONING:     electric cooling, packaged rooftop units. Unit
                                   selections shall conform to the following design
                                   criteria:

                                   o  Summer Design: indoor 24(degrees)C at 30(degrees)C outside ambient
                                      temperature.
                                   o  Winter Design: Indoor 24(degrees)C at -20(degrees)C outside ambient
                                      temperature.
                                   o  Minimum Fresh Air Rate: 20 cfm. Per person, based on 150
                                      square foot per person
</TABLE>

                                       -7-

<PAGE>

<TABLE>
<CAPTION>

BASE BUILDING SPECIFICATION                                               MENKES
--------------------------------------------------------------------------------
 PROJECT:     5520 & 5560 EXPLORER DRIVE, MISSISSAUGA, ONTARIO
                                                                  MARCH 30, 1999
--------------------------------------------------------------------------------
<S>                                <C>
                                   o  Internal Lighting Load: 1.5 watts per square foot*

                                   o  Office Equipment Load: 3.0 watts per square foot

                                   Control system to be Variable Volume and
                                   Temperature (V.V.T.). All internal rooftop unit
                                   control components required for the V.V.T.
                                   control system interface and the main trunk
                                   ductwork greater than 36" x 16" and the Master
                                   controllers, supplemental electric baseboard
                                   heaters shall be provided under the base
                                   building.

16           ELECTRICAL
                                   Main service to be 1600 amp., 3 phase, 600 volt
                                   service, taken from Public Utilities pad mounted
                                   transformer.

                                   Hydro utility charges included.

                                   Subtransformation and branch wiring is included to
                                   service:

                                      o  600v  equipment  (RTU,  door  openers)

                                      o  347v lighting

                                      o  120v  distribution part of Section 17.0 (capacity
                                          to provide 3 watts/s.f. "clean" power and 2
                                          watts/s.f. "regular" power available at each floor)

                                   Telephone outlets (part of Section 17.0).

                                   The following illumination is provided:

                                   Office:
                                   o 50 fc. In ceiling by fluorescent*
                                   o 35 fc. In washrooms by fluorescent

                                   Fire alarm included.
</TABLE>

                         * or as modified as per agreement between Landlord  and
                           Tenant

                                                -8-

<PAGE>

<TABLE>
<CAPTION>

BASE BUILDING SPECIFICATION                                               MENKES
--------------------------------------------------------------------------------
 PROJECT:     5520 & 5560 EXPLORER DRIVE, MISSISSAUGA, ONTARIO
                                                                  MARCH 30, 1999
--------------------------------------------------------------------------------
<S>                                <C>

                                   Exterior building and parking lot lighting to
                                   Municipal standards.

                                   Emergency  lighting by battery  packs to code
                                   requirements to suit open floor.

17           TENANT IMPROVEMENTS

       17.1  OFFICE FINISHES:      The Unfinished Office Premises (excludes exit stairs,
                                   main lobby, washrooms) shall be improved via a
                                   Tenant Improvement Allowance as set out in the
                                   Lease which shall provide for:
                                    o  Partitioning
                                    o  Special ceilings
                                    o  Special lighting
                                    o  Floor coverings
                                    o  Wall coverings
                                    o  Power distribution
                                    o  HVAC Distribution and controls
                                    o  Power and Raceways for Communication
                                    o  Security
                                    o  Doors and frames
                                    o  Hardware
                                    o  Millwork
                                    o  Miscellaneous  plumbing  fixtures
                                    o  Interior design
                                    o  Permits and Municipal Fees
                                    o  Management Fees
</TABLE>

                                                -9-

<PAGE>

                                           SCHEDULE "E"

                                       DEVELOPMENT SCHEDULE

JULY 15, 1999              Final Space Plan approved by Certicom

AUGUST 6, 1999             Equipment Lists, Power and Data requirements provided
                           by Certicom

SEPTEMBER 3,1999           Final Interior Working Drawings approved by Certicom,
                           ready for tender

                           - Details and finish materials
                           - Complete mechanical and electrical

SEPTEMBER 28, 1999         Submit  Construction Cost  Summary to  Certicom for
                           approval

OCTOBER 1, 1999            Final Approval of Construction Costs by Certicom  and
                           Direction to proceed

OCTOBER 18, 1999           Start Construction of Interior Finishes

DECEMBER 15, 1999          Substantial Completion
                           (Ready to start furniture and equipment installation)

<PAGE>

                                    SCHEDULE "F"
                                    ------------

                  [ SITE PLAN - PHASES 1 AND 2 MAP OMITTED ]

<PAGE>

                                     SCHEDULE "G"

                           EXCLUSIONS FROM OPERATING COSTS

There shall also be deducted  or  excluded,  as the case may be, from the costs,
taxes,  premiums,  fees,  outlays and expenses  referred to in the definition of
Operating Costs, the following:

       (i) all income tax or similar taxes,  corporation  taxes,  profits taxes,
excess  profits  taxes,  place of  business  taxes,  gift taxes,  estate  taxes,
succession taxes,  inheritance  taxes,  franchise taxes, land transfer taxes and
non-resident  sales  taxes,  business  taxes  (other than those  business  taxes
specifically  payable by the Tenant  pursuant to this lease) and any other taxes
personal to the Landlord other than capital taxes;

       (ii)  ground  rent (if any),  amortization  and  interest  on and capital
retirement of debt, affecting all or any of the lands and building;

       (iii) all recoveries  which reduce the expenses  incurred by the Landlord
in operating,  repairing and maintaining  the lands and building  (including the
common areas and  facilities)  received by the Landlord from tenants as a result
of any act,  omission,  default or  negligence of such tenants or by reason of a
breach of such tenants of provisions in their respective leases;

       (iv) any amounts directly chargeable to other tenants in the building for
services,  costs  and  expenses  solely  attributable  to the  accounts  of such
tenants;

       (v) any loss or damage to all or any part of the building or any personal
injury for which the Landlord is or ought to have been  insured  under the terms
of this lease;

       (vi) any cost or expense  which is normally  treated in  accordance  with
generally  accepted  accounting  principles  as being of a capital  nature which
shall be  amortized  over  useful  life of the item and charged to the Tenant in
accordance with G.A.A.P. as part of the Operating Costs;

       (vii) costs  recovered  by the  Landlord  in  exercising  the  Landlord's
construction warranties;

       (viii) commissions,  advertising costs, the costs of any market research,
traffic consumer attitude study or legal expenses in connection with leasing the
building or any part thereof;

       (ix) all penalties or carrying  charges relating to late payment of taxes
and any  capital,  interest  or  other  carrying  charges  on any  mortgages  or
equipment head or land lease or equipment lease payments or other financing with
respect to the building or any part thereof;

       (x) all fines,  suits,  claims,  demands,  actions,  costs,  charges  and
expenses of any kind or nature for which the Landlord is or may become liable by
reason of any  negligent  or wilful acts or  omissions to act on the part of the
Landlord or those for whom it is in law  responsible  or by reason of any breach
or  violation  or  non-performance  by the  Landlord  of any  covenant,  term or
provision  contained  in the leases  and other  agreements  entered  into by the
Landlord in respect of the building or the lands;

       (xii) the expenses incurred by the Landlord in respect of installation or
removal of any  tenant's  improvements  or any sum paid by the  Landlord  to any
tenant in the building for any tenant allowance;

       (xiii)  all  work to the  leased  premises  or the  building  or any part
thereof made necessary by the Landlord's  non-compliance  with governing  codes,
by-laws, regulations and ordinances relating to the construction by the Landlord
of the building or the Leased Premises; and

<PAGE>

                                   -31-

       (xiv) the cost of construction and reconstruction of the building.

<PAGE>

                                     RIDER 1

Notwithstanding  the foregoing  provisions or any other provision of this Lease,
the Landlord  shall provide the Tenant a gross Rent free period for the first 12
months of the Term on five thousand  (5,000) square feet of Rentable Area,  such
that the Tenant shall not be obligated to pay Base Rental or Additional Rent for
the first 12 months of the Term on five thousand (5,000) square feet of Rentable
Area.

<PAGE>

                               AMENDING AGREEMENT

THIS AMENDING AGREEMENT made this 25th day of April, 2000,

BETWEEN:

              AIRPORT CORPORATE CENTRE OFFICE PARK INC.

              (the "Landlord")

                                                               OF THE FIRST PART

AND:

              CERTICOM CORP.

              (the "Tenant")

                                                              OF THE SECOND PART

WHEREAS the Landlord and the Tenant entered into a Lease dated March 29th,  1999
(the "Lease") when the Tenant leased certain  premises  located at 5520 Explorer
Drive, in the City of Mississauga (the "Premises") as more  particularly set out
in the Lease;

AND WHEREAS the  Landlord has agreed to lease to the Tenant  certain  additional
premises known as Suite 202 containing 5,344 square feet at 5520 Explorer Drive,
in the City of Mississauga (the "Additional Premises");

AND WHEREAS the Landlord and the Tenant have agreed to enter into this  Amending
Agreement to amend the terms of the Lease in accordance with the terms herein;

NOW  THEREFORE   WITNESSETH  that  in  consideration  of  the  mutual  covenants
hereinafter exchanged, the parties agree as follows;

1.     The Landlord does hereby lease to the Tenant the Additional  Premises for
       a term of five (5) years commencing June 1st, 2000 and expiring May 31st,
       2005.

2.     The Tenant  covenants  and agrees to pay to the  Landlord as Base Rental,
       yearly and every year during the Term for the  Additional  Premises,  the
       sum of  $96,192.00  of lawful  money of Canada  in twelve  equal  monthly
       installments of $8,016.00 in advance,  the first of such  installments to
       become due and payable on the 1st of June, 2000. The Base Rental has been
       calculated on the basis of $18.00 per square foot of Rentable Area.

3.     The Tenant shall be entitled to enter the Additional Premises immediately
       for completion of its Tenant  improvements and shall not  be obligated to
       pay any Base Rental or Additional Rent until June 1st, 2000.

4.     The  Landlord  agrees to pay a one time cash payment of $20.00 per square
       foot of Rentable  Area plus  G.S.T.  for the  purpose of  permitting  the
       Tenant to perform its leasehold  improvements.  The payment shall be made
       upon  completion of the Tenant  improvements  and receipt by the Landlord
       of:

       (a)    satisfactory evidence of completion;

       (b)    a Workmen's Compensation clearance;

       (c)    evidence  that  there  are no  liens  attached  to the  Additional
              Premises or the lands thereunder; and

       (d)    subject to final  inspection  of the  Additional  Premises  by the
              Landlord.

<PAGE>

                                        2

       The  Landlord's  payment shall be subject to any required  holdback under
       the applicable legislation.

5.     It is agreed that the Landlord and Tenant's Work will include those items
       in accordance with the attached  Memorandum from Guy Belanger dated March
       7th, 2000 and be in compliance with same and the tenant shall be bound to
       comply with the terms  thereof.  It is agreed that the Landlord  will not
       charge  supervision  cost should the Tenant utilize the  Landlord's  base
       building engineers.

6.     The  Landlord  and  Tenant  agree  and  acknowledge  that  the  following
       provisions of the Lease are not  applicable to the  Additional  Premises:
       13.5 (leasehold improvement  allowance),  13.6 (leasehold  improvements),
       13.7 (base building) and Rider 1.

7.     The  capitalized  terms herein shall have the same  meanings  ascribed to
       them in the Lease unless specified otherwise herein.

8.     The Landlord and the Tenant hereby agree that the  definitions of "Leased
       Premises" and "Commencement  Date" in Article 1.1 of the Lease are hereby
       deleted and replaced with the following:

       "Leased Promises" means approximately 25,248 square feet of Rentable Area
       on the  fourth  floor of the  Building  as  outlined  in red on the plans
       attached as Schedule "B".

       "Commencement Date" means December 25th, 1999.

9.     The Landlord and the Tenant  hereby  agree  that the first two paragraphs
       and the fourth  paragraph of Article 2.3 of the Lease are hereby  deleted
       and replaced with the following:

       THE TENANT  SHALL PAY  yearly  and every  year  during the first five (5)
       years of the within Term the sum of $353,472.00 of lawful money of Canada
       in twelve (12) equal monthly installments of $29,456.00,  in advance, the
       first of such  installment  to become due and payable on the Commencement
       Date (the "Base Rental").

       THE TENANT SHALL PAY yearly and every year during the last five (5) years
       of the within Term the sum of  $403,968.00  of lawful  money of Canada in
       twelve (12) equal monthly  installments  of  $33,664.00, in advance,  the
       first of such  installment to become due and payable on the  Commencement
       Date (the "Base Rental").

       The  aforesaid  annual  Base  Rental  is  calculated  on the basis of the
       Rentable Area of the Leased  Premises  being 25,248 square feet at a rate
       of $14.00 for each  square  foot of  Rentable  Area per annum  during the
       first  five (5) years of the  within  Term and at the rate of $16.00  for
       each  square  foot of  Rentable  Area per annum  during the last five (5)
       years of the within Term.

10.    The Landlord and the Tenant agree that the terms of the Lease are amended
       as required  to give full force and effect to the terms of this  Amending
       Agreement.

11.    The  Landlord  and the Tenant  agree to execute  such  further  and other
       documentation  as may be necessary to give this Amending  Agreement  full
       force and effect.

12.    This Amending Agreement shall enure to and be binding upon the respective
       successors and assigns of the parties hereto.

<PAGE>

                                        3

IN WITNESS WHEREOF the parties hereto have executed this Amending Agreement as
of the day, month and year noted above.

                                       AIRPORT CORPORATE CENTRE OFFICE PARK INC.

                                       Per: ____________________________________
                                               [Authorized Signing Officer]

                                       CERTICOM CORP.

                                       Per: ____________________________________
                                               [Authorized Signing Officer]

<PAGE>

                                  SCHEDULE "A"

                  Memorandum from Guy Belanger dated March 7th, 2000.

March 7, 2000

Certicom Corporation
5520 Explorer Dr. -- 2nd Floor

Re: Tenant Improvements

The following base building work is in place:

Ceiling grid installed
Baseboard heaters installed
Sprinkler System installed
Supply only of light fixtures on floor within space
All mechanical and electrical rough-in

The only base building work not complete is the supply of ceiling tile

Specifications for Tenant Work:

All  mechanical  and  electrical  work  must be  designed  by the base  building
engineers. It is the Tenant's responsibility to ensure that all OBC requirements
are co-ordinated with the base building  architect where applicable.  A complete
set of drawings including mechanical,  electrical,  architectural, and sprinkler
must be approved by Menkes prior to the start of Construction.

It  will be the  Tenants  responsibility  to  obtain  and  pay for all  required
permits.  A copy of the permit must be forwarded to Menkes prior to the start of
any construction.

It is our preference to use base building  mechanical,  electrical and sprinkler
contractors.  All  contractors  must be  approved  by  Menkes  before  any  work
commences.

The base building  distribution  system  including VVT zone dampers and controls
supplied by Lennox must be used (same as 4th floor).  Base building air troffers
and perimeter  air boots must also be used.  VVT controls  including  base board
heaters and tie-in to base  building  system must be  implemented  in accordance
with base building  control  system.  A portion of the controls  related to this
tenant  space have already  been  installed.  The value of this work is $5,500 +
gst.

Menkes  reserves the right to review the completed  construction  and direct the
tenants to correct deficiencies to the landlords' satisfaction.  Upon completion
the  tenant  is to  provide  as built  drawings  approved  by the base  building
engineers. Provide 2 prints and CAD files of each. The tenant is also to provide
written  confirmation from the City of Mississauga  building department and fire
department that all permit requirements are satisfied.

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