LEASE

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





                                       -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





                                      -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





                                      -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,





                                      -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.





                                       -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.





                                       -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.





                                       -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




                                      -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:





                                      -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




                                      -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





                                      -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.





                                      -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





                                       -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.





                                      -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





                                      -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





                                      -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





                                      -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





                                      -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





                                      -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;


                                      -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





                                      -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





                                      -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





                                      -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.





                                      -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





                                      -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





                                      -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.





                                      -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)





                                  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.







                                  SCHEDULE "B"



                        [ FOURTH FLOOR PLAN MAP OMITTED ]




                                  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





                                       -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,





                                       -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





                                       -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.





                                  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








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


                                
 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



                                       -1-








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

                                
       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.



                                      -2-








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

                                
                                   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.



                                       -3-








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

                                
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



                                       -4-








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

                                
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.



                                      -5-







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

                                
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



                                      -6-








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



                                       -7-








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


                         * or as modified as per agreement between Landlord  and
                           Tenant

                                                -8-








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

                                   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



                                                -9-





                                           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)







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


                  [ SITE PLAN - PHASES 1 AND 2 MAP OMITTED ]






                                     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





                                   -31-

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







                                     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.





                               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.




                                        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.





                                        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]



                                  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.