<PAGE>   1
                                                                   EXHIBIT 10.27

                                 LEASE AGREEMENT







                                    LANDLORD


                            MARCO PLAZA ENTERPRISES,

                        a California general partnership



                                     TENANT


                              TRITEAL CORPORATION,

                             a Delaware corporation



<PAGE>   2






                               TABLE OF CONTENTS
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                                                                                                               Page
                                                                                                               ----
<S>                                                                                                         <C>
SUMMARY OF BASIC LEASE INFORMATION................................................................................i

ARTICLE 1 -- DEFINITIONS..........................................................................................1
         1.1      Acceleration Estimate...........................................................................1
         1.2      Additional Rent.................................................................................1
         1.3      Base Annual Rent................................................................................1
         1.4      Base Monthly Rent...............................................................................1
         1.5      Basic Terms.....................................................................................1
         1.6      Business Days...................................................................................1
         1.7      Commencement of Construction....................................................................1
         1.8      Common Area.....................................................................................1
         1.9      Common Area Maintenance Charges.................................................................1
         1.10     CPI.............................................................................................1
         1.11     Declarations....................................................................................1
         1.12     Fair Market Rent................................................................................2
         1.13     Excess Operating Costs Rent.....................................................................2
         1.14     Hazardous Materials.............................................................................2
         1.15     Insurance Charges...............................................................................2
         1.16     Hazardous Materials Laws........................................................................2
         1.17     Landlord's Indemnitees..........................................................................2
         1.18     Lease Term......................................................................................2
         1.19     Lease Year......................................................................................2
         1.20     Operating Costs.................................................................................2
         1.21     Premises........................................................................................3
         1.22     Profit..........................................................................................3
         1.23     Project.........................................................................................3
         1.24     Property Taxes..................................................................................3
         1.25     Rentable........................................................................................3
         1.26     Rent............................................................................................3
         1.27     Rules and Regulations...........................................................................3
         1.28     Site Amenities..................................................................................3
         1.29     Site Plan.......................................................................................3
         1.30     Target Commencement Date........................................................................3
         1.31     Tenant's Indemnitees............................................................................3
         1.32     Tenant Improvements.............................................................................3
         1.33     Tenant's Proportional Share.....................................................................3
         1.34     Usable..........................................................................................4
         1.35     Work Letter.....................................................................................4

ARTICLE 2 -- PREMISES.............................................................................................4
         2.1      Lease...........................................................................................4
                  2.1.1    Premises...............................................................................4
                  2.1.2    Site Plan..............................................................................5
         2.2      Lease of the Premises...........................................................................5
         2.3      Suitability of Premises.........................................................................5
         2.4      Landlord's Work in the Premises and Project.....................................................5

ARTICLE 3 -- LEASE TERM...........................................................................................5
         3.1      Lease Term......................................................................................5
         3.2      Commencement Date...............................................................................5
</TABLE>


                                     I-(i)
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<TABLE>
<S>                                                                                                         <C>
         3.3      Delay in Commencement...........................................................................5
                  3.3.1    Acceptance Letter......................................................................5
                  3.3.2    Acceleration Estimate..................................................................6
                  3.3.3    LIQUIDATED DAMAGES.....................................................................6
                  3.3.4    Early Completion.......................................................................6
         3.4      Early Occupancy.................................................................................6
         3.5      Option(s) to Extend Term........................................................................7
                  3.5.1    Extension Notice.......................................................................7
                  3.5.2    Base Monthly Rent During Extension.....................................................7

ARTICLE 4 -- RENTAL AND OTHER PAYMENTS............................................................................8
         4.1      Base Monthly Rent...............................................................................8
         4.2      Interest on Past Due Obligations................................................................8
         4.3      Late Charges....................................................................................8
         4.4      Security Deposit; Additional Security and Loans.................................................8
                  4.4.1    Deposit of Funds.......................................................................8
                  4.4.2    Return of Security Deposit.............................................................8
                  4.4.3    Additional Security and Loans..........................................................9
                  4.4.4    Transfer of Security Deposit and Additional Security...................................9

ARTICLE 5 -- OTHER CHARGES PAYABLE BY TENANT......................................................................9
         5.1      Rent............................................................................................9
         5.2      Common Area Maintenance Charges.................................................................9
                  5.2.1    Tenant to Bear Proportional Share of Common Area Maintenance Charges...................9
                  5.2.2    Landlord's Common Area Maintenance Charges.............................................9
                  5.2.3    Exclusions from Common Area Maintenance Charges.......................................10
                  5.2.4    Repairs Due to Misuse.................................................................10
         5.3      Payment of Excess Operating Costs Rent.........................................................10
                  5.3.1    Previous Charges......................................................................10
                  5.3.2    Year-End Adjustments..................................................................11
                  5.3.3    Audit.................................................................................11
         5.4      Personal Property Taxes........................................................................11

ARTICLE 6 -- USE OF PROPERTY.....................................................................................11
         6.1      Permitted Uses.................................................................................11
         6.2      Manner of Use..................................................................................11
                  6.2.1    Interference with Use/Nuisance........................................................11
                  6.2.2    Violation of Law/Insurance Provisions.................................................12
                  6.2.3    Permits...............................................................................12
         6.3      Rules and Regulations..........................................................................12
         6.4      Landlord's Access..............................................................................12
         6.5      Quiet Possession...............................................................................12

ARTICLE 7 -- HAZARDOUS MATERIALS.................................................................................13
         7.1      Prohibition....................................................................................13
                  7.1.1    Use...................................................................................13
                  7.1.2    Normal Usage..........................................................................13
         7.2      Disclosure and Warning Obligations.............................................................13
         7.3      Notice of Actions..............................................................................13
         7.4      Hazardous Materials Indemnity..................................................................14
         7.5      Assignment and Subletting......................................................................14
         7.6      Environmental Tests and Audits.................................................................14
         7.7      Lease "As Is"..................................................................................14
         7.8      Survival.......................................................................................14
</TABLE>
                                     I-(ii)
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<TABLE>
<S>                                                                                                         <C>
ARTICLE 8 -- UTILITIES...........................................................................................15
         8.1      Payment and Arrangement........................................................................15
         8.2      Interruption of Services and Utilities.........................................................15
         8.3      Operating Hours................................................................................15

ARTICLE 9 -- PARKING AND CONTROL OF COMMON AREAS.................................................................15
         9.1      Control of Common Areas by Landlord............................................................15
         9.2      License........................................................................................16

ARTICLE 10 -- ALTERATIONS, IMPROVEMENTS AND SIGNAGE..............................................................16
         10.1     Changes/Alterations............................................................................16
         10.2     Manner of Construction.........................................................................16
                  10.2.1  Conditions to Consent..................................................................16
                  10.2.2  Cost...................................................................................16
                  10.2.3  Good and Workmanlike Manner............................................................16
         10.3     Construction Insurance.........................................................................17
         10.4     Liens..........................................................................................17
         10.5     Signage........................................................................................17

ARTICLE 11 -- INSURANCE AND INDEMNITY............................................................................17
         11.1     Insurance to be Obtained by Landlord...........................................................17
                  11.1.1  Fire and Casualty Insurance............................................................17
                  11.1.2  Liability Insurance....................................................................17
         11.2     Insurance to be Obtained by Tenant.............................................................18
                  11.2.1  Liability Insurance....................................................................18
                  11.2.2  Insurance of Personal Property.........................................................18
                  11.2.3  Additional Insurance Obligations.......................................................18
         11.3     Waiver of Subrogation..........................................................................18
         11.4     Form of Policies...............................................................................18
         11.5     Indemnification................................................................................19
                  11.5.1  Indemnification of Landlord............................................................19
                  11.5.2  Landlord's Nonliability................................................................19
                  11.5.3  Indemnification of Tenant..............................................................19

ARTICLE 12 -- ASSIGNMENT AND SUBLETTING..........................................................................19
         12.1     Landlord's Consent Required....................................................................19
                  12.1.1  Transfer...............................................................................19
                  12.1.2  Procedure..............................................................................20
                  12.1.3  Affiliates.............................................................................20
         12.2     Recapture Right................................................................................20
         12.3     Transfer Without Consent.......................................................................20
         12.4     No Release of Tenant...........................................................................20
         12.5     Effect of a Transfer...........................................................................20
         12.6     Event of Bankruptcy............................................................................21
         12.7     No Merger......................................................................................21
         12.8     Assignment Fees and Procedures.................................................................21

ARTICLE 13 -- DAMAGE OR DESTRUCTION..............................................................................21
         13.1     Repair of Damage by Landlord...................................................................21
         13.2     Rent Abatement Due to Casualty.................................................................22
         13.3     Landlord's Option to Repair....................................................................22
         13.4     Damage Near End of Term........................................................................22
         13.5     Waiver of Statutory Provisions.................................................................22
</TABLE>
                                    I-(iii)
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<TABLE>
<S>                                                                                                         <C>
ARTICLE 14 -- CONDEMNATION.......................................................................................22
         14.1     Total Condemnation.............................................................................22
         14.2     Partial Condemnation...........................................................................22
         14.3     Condemnation of Parking Area...................................................................23
         14.4     Distribution of Condemnation Award.............................................................23
         14.5     Waiver.........................................................................................23

ARTICLE 15 -- DEFAULTS; REMEDIES.................................................................................23
         15.1     Covenants and Conditions.......................................................................23
         15.2     Defaults by Tenant.............................................................................23
         15.3     Remedies.......................................................................................24
         15.4     The Right to Relet the Premises................................................................25
         15.5     Waiver of Rights of Redemption.................................................................25
         15.6     Cumulative Remedies............................................................................25
         15.7     Additional Remedies Upon Default...............................................................25
                  15.7.1  Assumption or Rejection of Lease.......................................................25
                  15.7.2  Assignment.............................................................................26
                  15.7.3  Other Matters..........................................................................26
         15.8     Default by Landlord............................................................................26
         15.9     Landlord's Cure................................................................................26

ARTICLE 16 -- PROTECTION OF CREDITORS............................................................................27
         16.1     Subordination..................................................................................27
         16.2     Attornment.....................................................................................27
         16.3     Signing of Documents...........................................................................27
         16.4     Estoppel Certificates..........................................................................27
                  16.4.1  Request................................................................................27
                  16.4.2  Failure to Respond.....................................................................27
         16.5     Tenant's Financial Condition...................................................................27
         16.6     Mortgagee Protection Clause....................................................................28

ARTICLE 17 -- TERMINATION OF LEASE...............................................................................28
         17.1     Condition Upon Termination.....................................................................28
         17.2     Non-Removal by Tenant..........................................................................28
         17.3     Abandoned Property.............................................................................28
         17.4     Landlord's Actions on Premises.................................................................29
         17.5     Holding Over...................................................................................29

ARTICLE 18 -- MISCELLANEOUS PROVISIONS...........................................................................29
         18.1     Right of First Refusal.........................................................................29
         18.2     Successors; No Third Party Beneficiaries.......................................................29
         18.3     Severability...................................................................................30
         18.4     Interpretation.................................................................................30
         18.5     Other Tenancies................................................................................30
         18.6     Entire Agreement...............................................................................30
         18.7     Landlord's Liability...........................................................................30
         18.8     Notices........................................................................................30
         18.9     Waivers........................................................................................30
         18.10    No Recordation.................................................................................31
         18.11    Choice of Law..................................................................................31
         18.12    Corporate Authority; Partnership Authority.....................................................31
         18.13    No Partnership.................................................................................31
         18.14    Joint and Several Liability....................................................................31
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                                     I-(iv)
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<S>                                                                                                         <C>
         18.15    Attorneys' Fees................................................................................31
         18.16    Lender Modification............................................................................31
         18.17    Brokers........................................................................................31
         18.18    Force Majeure..................................................................................32
         18.19    Tenant Obligations Survive Termination.........................................................32
         18.20    Tenant's Waiver................................................................................32
         18.21    Submission of Lease............................................................................33
||
                                    EXHIBITS

         Exhibit "A"......................................................................................Site Plan

         Exhibit "B"..........................................................................Rules and Regulations

         Exhibit "C"....................................................................................Work Letter

         Exhibit "D"....................................................................................Definitions

         Exhibit "E" .............................................................................Acceptance Letter
</TABLE>



                                     I-(v)
<PAGE>   7






                                 LEASE AGREEMENT

                       SUMMARY OF BASIC LEASE INFORMATION


<TABLE>
<S>                                         <C>
1.       Lease Date:                            April ___, 1997

2.       Landlord:                              Marco Plaza Enterprises, a California general partnership

3.       Address of Landlord:                   c/o Newport National Corporation
                                                5050 Avenida Encinas, Suite 350
                                                Carlsbad, CA 92008
                                                Attn:  Mr. Jeffry Brusseau

4.       Tenant:                                Triteal Corporation, a Delaware corporation

5.       Address of Tenant:                     2011 Palomar Airport Road, Suite 200
                                                Carlsbad, CA 92009-1431
                                                Attn: General Counsel

6.       Premises (Section                      Project Rentable Area:  Approximately 51,000 square feet
         2.1 of Lease):                         (as of Lease Date)

                                                Building Rentable Area:  Approximately 51,000 square feet

                                                Premises Rentable Area: Approximately 51,000 square feet

7.       Project:                               Cornerstone Corporate Centre

         Building:                              Building D

8.       Lease Term
         (Article 3 of Lease):                  Lease Term:  Ten (10) years

                                                Target Commencement Date:  Subject to Section 1.30, April 15, 1998

                                                Target Expiration Date:  Subject to Section 1.30, April 14,  2008

                                                Liquidated Damages for Substantial Completion of Premises after
                                                Target Commencement Date:  Tenant's actual hold-over rents, not
                                                to exceed $1,000/day.

                                                Incentive Fee for Substantial Completion of Premises prior to
                                                Target Commencement Date:  Subject to provisions of Section
                                                3.3.4, cash equal to the Acceleration Estimate

                                                Options to Extend:  Two (2) for five (5) years each
</TABLE>


4/15/97                     II-(i)                    Landlord Initials: _______
                                                        Tenant Initials: _______


<PAGE>   8


<TABLE>
<S>                                         <C>
9.       Rent                                   Base Monthly Rent:

         (Article 4 of Lease)                          $1.64 per Rentable square foot of the Premises per month,
                                                       which shall increase as follows:
</TABLE>
<TABLE>
<CAPTION>
                                                                                Base Monthly Rent
                                                     Lease Years              (Per Rentable Sq. Ft.
                                                                                   of Premises)
                                              ------------------------------------------------------------
<S>                                                                         <C>
                                                         1-3                          $1.64
                                              ------------------------------------------------------------
                                                         4-6                           1.79
                                              ------------------------------------------------------------
                                                         7-9                           1.95
                                              ------------------------------------------------------------
                                                          10                           2.12
                                              ------------------------------------------------------------
</TABLE>
<TABLE>
<S>                                          <C>
                                                Initial Base Monthly Rent:  $83,640 (assumes Premises = 51,000)

                                                Initial Base Annual Rent:  $1,003,680 (assumes Premises = 51,000)

                                                Base Monthly Rent During Extensions: At commencement of each 
                                                Extension Term, Fair Market Rent to be increased by 9% (nine
                                                percent) after three (3) years of such Extension Term.

                                                First Month's Base Monthly Rent due upon execution of Lease:
                                                $83,640

                                                Late Charge:  Ten percent (10%) of the overdue amount

                                                Lease Interest Rate:  Twelve percent (12%)

10.      Operating Costs Allowance              Operating Costs during first (1st) Lease Year
         (Article 5 of Lease):

11.      Use (Article 6 of Lease):              General office and other uses consistent with a computer software
                                                development company, in conformance with the Declarations and all
                                                laws, ordinances, and regulations.

12.      Security Deposit                       $83,640
         (Article 4 of Lease):

13.      Brokers (Section                       Landlord's Broker:  Business Real Estate
         19.17 of Lease):                       Tenant's Broker:  The Irving Hughes Group, Inc.

14.      Lease Guarantors:                      None

15.      Tenant Improvement Allowance           Up to Thirty Dollars ($30) per Usable   (See Work Letter -
                                                Exhibit "C") square foot of the Premises

16.      Tenant Contingency Allowance:          Up to Two Dollars ($2) per Usable square foot of the Premises.
         (See Work Letter -- Exhibit "C")

17.      Right of First Refusal to Lease:       All or any portion of Building C in the Project, within five (5)
                                                Business Days after notice.
</TABLE>


4/15/97                                               Landlord Initials: _______
                                    II-(ii)             Tenant Initials: _______
                                    
<PAGE>   9
<TABLE>
<S>                                                                                     <C>
18.      The following exhibits are attached hereto and incorporated into this Lease:

         Exhibit "A"......................................................................................Site Plan

         Exhibit "B"..........................................................................Rules and Regulations

         Exhibit "C"....................................................................................Work Letter

         Exhibit "D"....................................................................................Definitions

         Exhibit "E" .............................................................................Acceptance Letter
</TABLE>


         The foregoing Summary of Basic Lease Information is hereby incorporated
into and made a part of this Lease. Each reference in this Lease to the Summary
of Basic Lease Information shall mean the information set forth above and shall
be construed to incorporate all of the terms provided under the particular lease
paragraph pertaining to such information. In the event of a conflict between the
Summary of Basic Lease Information and the Lease, the terms of the Lease shall
prevail.

                       LANDLORD:

                       MARCO PLAZA ENTERPRISES, a California general partnership


                       By:               /s/ Robert Kronick
                          ------------------------------------------------------
                       Name:             Robert Kronick
                            ----------------------------------------------------
                       Title:            Partner
                             ---------------------------------------------------

                       TENANT:


                       TRITEAL CORPORATION, a Delaware corporation


                       By:               /s/ Gregory Jay White
                          ------------------------------------------------------
                       Name:             Gregory Jay White
                            ----------------------------------------------------
                       Title:            TriTeal Corporation
                             ---------------------------------------------------


4/15/97                                               Landlord Initials: _______
                                    II-(iii)            Tenant Initials: _______

<PAGE>   10
                                 LEASE AGREEMENT


         This Lease Agreement, which includes the Basic Terms (as hereinafter
defined) ("Lease"), is made as of the date shown in the Basic Terms, by and
between the Landlord shown in the Basic Terms and the Tenant shown in the Basic
Terms.

                            ARTICLE 1 -- DEFINITIONS

         In addition to the defined terms set forth in the Basic Terms or
elsewhere in this Lease, unless the context otherwise requires, the following
terms shall have the meanings set forth below.

         1.1      ACCELERATION ESTIMATE. "Acceleration Estimate" means an 
estimate Landlord shall obtain promptly after Commencement of Construction 
(i) if Commencement of Construction occurs after August 1, 1997, and (ii) of the
additional costs of construction (both hard costs such as materials and soft
costs such as engineering and architectural fees) which Landlord reasonably
anticipates incurring in order to achieve Substantial Completion of the
Improvements by the Target Commencement Date.

         1.2      ADDITIONAL RENT. "Additional Rent" refers collectively to
Excess Operating Costs Rent and any other charges due and payable by Tenant
under this Lease other than Base Monthly Rent.

         1.3      BASE ANNUAL RENT. "Base Annual Rent" shall mean the sum of the
twelve (12) Base Monthly Rent amounts due in any Lease Year.

         1.4      BASE MONTHLY RENT. "Base Monthly Rent" means the rental
specified in Article 4 of this Lease.

         1.5      BASIC TERMS. "Basic Terms" means the Summary of Basic Lease
Information set forth at the beginning hereof.

         1.6      BUSINESS DAYS. "Business Days" means any day on which business
is conducted by federal savings banks in San Diego County, California.

         1.7      COMMENCEMENT OF CONSTRUCTION. "Commencement of Construction"
means the date on which Landlord's Contractor (as defined in the Work Letter)
commences the foundation for the Building.

         1.8      COMMON AREA. "Common Area" means all areas, space, equipment
and special services in the Building and in the Project which are from
time-to-time provided by Landlord for the common or joint use and benefit of the
occupants of the Project and Building, their employees, agents, servants,
customers and other invitees, including without limitation, parking areas,
access roads, driveways, retaining walls, landscaped areas, truck service-ways,
stairs, ramps, sidewalks, pools, patios, hardscapes, electrical rooms,
mailrooms, common area restrooms and locker rooms and hallways.

         1.9      COMMON AREA MAINTENANCE CHARGES. "Common Area Maintenance
Charges" means the costs and expenses described in Section 5.4.2 of this Lease.

         1.10     CPI. "CPI" shall mean the Consumer Price Index published by 
the United States Bureau of Labor Statistics, Los Angeles-Anaheim-Riverside, All
Urban Consumers (1982 - 84 = 100), or a successor or similar statistic selected
by Landlord in the event the present index is no longer published.

         1.11     DECLARATIONS. "Declarations" means any Declaration or 
Declarations of Covenants, Conditions and Restrictions which have been or may be
recorded against the Building or all or a portion of the Project, including, but
not limited to, (i) that certain Declaration of Covenants, Conditions, and
Restrictions, Carlsbad Airport Centre, dated September 4, 1986, recorded
September 12, 1986, in the San Diego County Recorder's Office, Document No.

4/17/97                                               Landlord Initials: _______
                                   1                    Tenant Initials: _______

<PAGE>   11
86-401456, as amended by a First Amendment dated January 15, 1987, recorded
January 28, 1987, as Document No. 87-048040, and (ii) that certain Mutual
Easement Agreement between Carlsbad Airport Centre and Opus Southwest
Corporation dated January 27, 1987, recorded in the San Diego County Recorder's
Office on January 28, 1987, as Document No. 87-048043.

         1.12     FAIR MARKET RENT. "Fair Market Rent" shall mean the price 
that a ready and willing single tenant would pay, as of the commencement of the
Extension Term, as annual rent to a ready and willing landlord for property
comparable to the Premises on the terms of this Lease, if such property were
exposed for lease on the open market for a reasonable period of time. As used
herein, "comparable property" shall mean an office building similar to the
Building in a project similar to the Project located in the Carlsbad, California
area, with improvements similar in age and character to the Premises, which has
been improved with tenant improvements comparable to those constructed in the
Building; provided, however, that the value of the equipment which Tenant is
entitled to remove at the expiration or termination of the Term of this Lease
shall be disregarded. All relevant factors shall be considered, including,
without limitation, the fact that this Lease is a full service, modified gross
lease, net of concessions and tenant improvement allowances generally being
offered by landlords of comparable properties, the age of the improvements, the
condition of the Premises, the rental market conditions then in existence,
whether Landlord will or will not be required to pay a real estate brokerage
commission.

         1.13     EXCESS OPERATING COSTS RENT. "Excess Operating Costs Rent"
means Tenant's Proportional Share of the amount by which the Operating Costs for
each calendar year exceeds the Operating Costs Allowance (as set forth in the
Basic Terms).

         1.14     HAZARDOUS MATERIALS. The term "Hazardous Material(s)" shall 
mean any toxic or hazardous substance, material or waste or any pollutant or
contaminant or infectious or radioactive material which are, or in the future
become, regulated under applicable local, state or federal law for the
protection of health or the environment, or which are classified as hazardous or
toxic substances, materials or wastes, pollutants or contaminants, as defined,
listed or regulated by any federal, state or local law, regulation or order or
by common law decision, including, without limitation, (i) trichloroethylene,
tetrachloroethylene, perchloroethylene and other chlorinated solvents, (ii)any
petroleum products or fractions thereof, (iii)asbestos, (iv)polychlorinated
biphenyls, (v) flammable explosives, (vi) urea formaldehyde and (vii)
radioactive materials and waste.

         1.15     INSURANCE CHARGES. "Insurance Charges" shall mean any and all
premiums and other costs for insurance policies insuring the Premises, Building,
Project and Common Area, required by this Lease and paid by Landlord.

         1.16     HAZARDOUS MATERIALS LAWS. The term "Hazardous Materials 
Law(s)" shall mean any federal, state or local laws, ordinances, codes,
statutes, regulations, administrative rules, policies and orders, and other
authority, existing now or in the future, which classify, regulate, list or
define hazardous substances, materials, wastes contaminants, pollutants and/or
the Hazardous Materials.

         1.17     LANDLORD'S INDEMNITEES. "Landlord's Indemnitees" shall refer
collectively to Landlord's agents, partners, members, managers, shareholders,
officers, directors, employees, successors and/or assigns.

         1.18     LEASE TERM. "Lease Term" means the entire period commencing
with the Commencement Date and continuing for the period specified in Item 8 of
the Basic Terms, plus any extensions, renewals or holding over periods.

         1.19     LEASE YEAR. "Lease Year" or "lease year" shall mean a 
consecutive twelve (12) month period during the Lease Term commencing on the
Commencement Date; provided that the Lease Year may be adjusted by Landlord to
commence on the first day of a calendar month after the Commencement Date.

         1.20     OPERATING COSTS. "Operating Costs" means all of the Common
Area Maintenance Charges, Property Taxes, and Insurance Charges.


4/15/97                                               Landlord Initials: _______
                                   2                    Tenant Initials: _______

<PAGE>   12

         1.21     PREMISES. "Premises" means the space described in Section 2.1
and delineated on the Site Plan.

         1.22     PROFIT. "Profit" shall mean rent and all other amounts paid or
payable by a transferee to Tenant pursuant to a Transfer (as defined in Article
11 herein) which is in excess of the scheduled Base Monthly Rent and all other
Rent due hereunder.

         1.23     PROJECT. "Project" means the project at the address set forth
in the Basic Terms, and more particularly described in the Site Plan, together
with all fixtures, equipment and personal property owned by Landlord, now or
hereafter situated or located therein or thereupon and used in connection with
the operation and maintenance thereof.

         1.24     PROPERTY TAXES. "Property Taxes" means: (i) general real
property and improvements taxes, any form of assessment, special assessment or
reassessment, any fee, license fee, license tax, business license fee,
commercial rental tax, levy, charge, assessment, penalty or other tax imposed by
any authority having the direct or indirect power to tax, including any city,
county, state or federal government, or any school, agriculture, lighting,
drainage or other improvement district thereof, as against any legal or
equitable interest of Landlord in the Project; (ii) any tax on the Landlord's
right to receive, or the receipt of, rent or income from the Project or against
Landlord's business of leasing the Project; (iii) any tax or charge for fire
protection, streets, sidewalks, road maintenance, refuse or other services
provided to the Project by any governmental agency; (iv) any tax imposed upon
this transaction or based upon a reassessment of the Project due to a change in
ownership or transfer of all or part of Landlord's interest in the Project; and
(v) any charge or fee replacing any tax previously included within the
definition of Property Taxes. "Property Taxes" does not, however, include
Landlord's Federal or State income, franchise, inheritance or estate taxes.

         1.25     RENTABLE. "Rentable" area or "Rentable" square feet shall mean
the square footage determined according to the definitions set forth on Exhibit
"D" attached hereto.

         1.26     RENT. "Rent" and/or "rent" shall mean the Base Monthly Rent,
Additional Rent and any other amounts Tenant is required to pay under this
Lease.

         1.27     RULES AND REGULATIONS. "Rules and Regulations" mean the rules
and regulations set forth in Exhibit "B" attached to this Lease.

         1.28     SITE AMENITIES. "Site Amenities" shall mean the sand 
volleyball court, barbeque area, lap pool, spa/jacuzzi, lunch patio, jogging
trail, and one-half court for basketball (over portions of the Project parking
lot) to be constructed by Landlord at its sole cost in a location selected by
Landlord in the Common Area, for the non-exclusive use of Tenant and other
occupants of the Project, in accordance with this Lease.

         1.29     SITE PLAN. "Site Plan" refers to the Site Plan attached as
Exhibit "A."

         1.30     TARGET COMMENCEMENT DATE. "Target Commencement Date" means 
April 15, 1998; provided, however, that if the Commencement of Construction
occurs after August 1, 1997 and Tenant disapproves the Acceleration Estimate
pursuant to Section 3.3.2, then the Target Commencement Date shall be April 15,
1998 plus the number of days after August 1, 1997, that the Commencement of
Construction occurred.

         1.31     TENANT'S INDEMNITEES. "Tenant's Indemnitees" shall refer
collectively to Tenant's agents, partners, members, managers, shareholders,
officers, directors, employees, successors and/or assigns.

         1.32     TENANT IMPROVEMENTS. "Tenant Improvements" shall refer to the
Tenant Improvements as defined in the Work Letter attached hereto as Exhibit
"C."

         1.33     TENANT'S PROPORTIONAL SHARE. "Tenant's Proportional Share"
shall mean all of Tenant's Building Proportional Share, Tenant's Project
Proportional Share and Tenant's Site Amenities Proportional Share.

4/15/97                                               Landlord Initials: _______
                                   3                    Tenant Initials: _______
<PAGE>   13

Tenant's Building Proportional Share shall be calculated from time to time as
determined by Landlord and shall be the percentage obtained by dividing the
rentable square footage of the Premises by the total rentable square footage of
the Building. Tenant's Project Proportional Share shall be calculated from time
to time as determined by Landlord and shall be the percentage obtained by
dividing the rentable square footage of the Premises by the total rentable
square footage of the Project as then constructed. Tenant's Site Amenities
Proportional Share shall be an amount rather than a fraction, shall be
calculated from time to time as determined by Landlord, and shall be calculated
pursuant to the following:

  If A          =        Total Common Area Maintenance Charges allocable to
                         the Site Amenities in excess of the Operating Costs
                         Allowance allocable to the Site Amenities; and
     B          =        Total Rentable square footage of the Project leased and
                         occupied by tenants with rights to use the Site
                         Amenities; and
     C          =        Total Rentable square footage of the Premises within
                         the Building;
     D          =        Total Rentable square footage of the Project planned;
                         and
     X          =        Tenant's share of Common Area Maintenance Charges for
                         the Site Amenities;


B - C
-----
D - C



Tenant's Building Proportional Share, Tenant's Project Proportional Share and
Tenant's Site Amenities Proportional Share shall initially be calculated using
the numbers set forth in Item 6 of the Basic Terms.

         1.34     USABLE. "Usable" square feet shall mean the square footage
determined according to the definitions set forth on Exhibit "D."

         1.35     WORK LETTER. "Work Letter" means the Work Letter which is
attached to this Lease as Exhibit"C."

                              ARTICLE 2 - PREMISES

         2.1 LEASE. Upon and subject to the terms, covenants and conditions
hereinafter set forth, Landlord hereby leases to Tenant and Tenant hereby leases
from Landlord the Premises. By execution of this Lease, the parties acknowledge
that the Option to Lease entered into as of January 29, 1997, by and between
Landlord and Tenant ("Option to Lease"), has been exercised by Tenant and the
Option to Lease shall be deemed terminated and superseded in its entirety by the
terms and provisions of this Lease. Notwithstanding the foregoing, concurrently
with the execution of this Lease, Tenant shall pay to Landlord all amounts of
the Option Consideration (as defined in the Option to Lease) which have not been
paid as of such date of execution. Landlord's concurrent receipt of such amounts
is a condition precedent to the effectiveness of this Lease, which condition is
to Landlord's benefit only.

         2.1.1 PREMISES. The Premises will be the Building. The Building will
be, in turn, located in and constitute a portion of the Project. Landlord
reserves the right to change the shape, size, location, number and extent of the
improvements shown on the Site Plan and eliminate or add any improvements to any
portion of the Project as provided in Article 5, provided there is no change to
the Site Amenities (except in accordance with this Lease) and no material
adverse impact on access to the Premises. Upon Substantial Completion (as
defined in the Work Letter) of the Building, the Rentable area of the Premises
shall be determined in accordance with the Work Letter and Exhibit "D." In the
event that Landlord determines that the Rentable area of any of the Premises,
Building or the Project differ from the amount set forth in the Basic Terms, all
amounts, percentages and figures appearing or referred to in this Lease,
including, without limitation, Tenant's Proportional Share, based upon such
amount shall be revised accordingly and such revised figures shall be deemed to
be the Rentable area of the Premises, Building or Project, respectively. In such
case, the Base Monthly Rent and any other payments due hereunder which are based
on a Rentable square footage basis shall be increased or decreased accordingly.

4/15/97                                               Landlord Initials: _______
                                   4                    Tenant Initials: _______

<PAGE>   14

                  2.1.2 SITE PLAN. The purpose of the Site Plan is to show the
approximate location of the Premises. Notwithstanding any other provision
contained in this Lease, Landlord reserves the right at any time to vary and
adjust the size of the various buildings (other than the Building), the location
of any other tenant automobile parking areas, the Site Amenities (except in
accordance with this Lease), and other common areas as shown on said Site Plan,
provided, however, that said parking area (including landscaped common areas)
shall at all times provide for not less than the minimum parking required by the
local jurisdiction in which the Project is located.

         2.2 LEASE OF THE PREMISES. Tenant acknowledges that this Lease is
subordinate and subject to the Declarations, all liens, encumbrances, deeds of
trust, reservations, restrictions and other matters affecting the Project or the
Premises and any law, regulation, rule, order or ordinance of any governmental
entity applicable to the Project or the Premises or the use or occupancy
thereof, in effect on the execution of this Lease or thereafter promulgated.
Landlord grants Tenant during the Lease Term the concurrent right to use the
Common Area and the Site Amenities on a nonexclusive basis and subject to the
provisions of this Lease; provided, however, that so long as Tenant is the only
occupant or tenant of the Building, Tenant shall have the exclusive right to use
the Common Area within the Building on an exclusive basis. Easements for light
and air are not included in the leasing of these Premises to Tenant. Landlord
further reserves the exclusive right of access to the roof, except for any
rights of access specifically granted to Tenant under the terms of this Lease or
any rights of access approved by Landlord, in its sole discretion, in writing.

         2.3 SUITABILITY OF PREMISES. Tenant acknowledges that, except as
expressly set forth herein, Landlord has made no representation or warranty
regarding the condition of the Premises or the Project or the suitability of
such Premises or the Project for the operation or conduct of Tenant's business
thereon or for any other purpose. The taking of possession of the Premises by
Tenant shall conclusively establish that the Premises and the Project were
acceptable to Tenant and in satisfactory condition to conduct business at such
time.

         2.4 LANDLORD'S WORK IN THE PREMISES AND PROJECT. The Premises shall be
completed as set forth in the Work Letter. Except as specifically set forth in
this Lease and the Work Letter, Landlord shall not provide or pay for any
interior improvement work or services related to the improvement of the Premises
or the construction of the Project. Tenant specifically acknowledges that
Landlord is under no obligation to construct all or any portion of the Project
except as set forth in this Lease, and Tenant will have no claim against
Landlord should Landlord decide for any reason or no reason to not build any
improvements or the Project except as set forth herein.

                             ARTICLE 3 - LEASE TERM

         3.1 LEASE TERM. The term of this Lease ("Lease Term") shall be for the
period of time specified in the Basic Terms, but shall be extended to include
any fraction of a calendar month between the commencement of the Lease Term and
the first day of the first full calendar month thereafter. Notwithstanding the
Lease Term, this Lease is a binding contract between Landlord and Tenant from
and after the date of full execution and delivery hereof by both parties,
enforceable in accordance with its terms.

         3.2 COMMENCEMENT DATE. The commencement date of the Lease Term
("Commencement Date") shall be the earlier of the date of the Substantial
Completion of the Premises or the date Tenant occupies the Premises in
accordance with the Work Letter.

         3.3 DELAY IN COMMENCEMENT. Landlord will use its diligent, good faith
efforts to Substantially Complete the Premises by the Target Commencement Date
(as such date may be extended due to a Tenant Delay [as defined in the Work
Letter]) or as set forth anywhere in this Lease or the Work Letter. If Landlord
cannot Substantially Complete the Premises by the Target Commencement Date, this
Lease shall not be void or voidable, nor shall Landlord be liable to Tenant for
any loss or damage resulting therefrom except as specifically set forth in
Section 3.3.3 below.

                  3.3.1    ACCEPTANCE LETTER. Upon Substantial Completion of the
Premises, Tenant shall, within five (5) days of request therefor by Landlord,
execute an acceptance letter ("Acceptance Letter") in substantially the form


4/15/97                                               Landlord Initials: _______
                                   5                    Tenant Initials: _______

<PAGE>   15

of the Acceptance Letter attached hereto as Exhibit "E"; provided, however, that
the failure of Tenant to execute such Acceptance Letter shall not affect any
obligation of Tenant hereunder or Landlord's determination of the Commencement
Date. If the Tenant fails to execute and deliver such Acceptance Letter in the
form proposed by Landlord, then Landlord and any prospective purchaser or
encumbrancer may conclusively presume and rely upon the following facts: (i)
that the Premises were in an acceptable condition and were delivered in
compliance with all requirements of the Work Letter and (ii) the Commencement
Date is the date specified in the Acceptance Letter proposed by Landlord.

                  3.3.2 ACCELERATION ESTIMATE. If the Commencement of
Construction occurs after August 1, 1997, Landlord shall deliver the
Acceleration Estimate to Tenant within thirty (30) days after the Commencement
of Construction. Tenant shall have ten (10) days to either approve or disapprove
the Acceleration Estimate by written notice to Landlord. Failure of Tenant to
timely deliver such written notice to Landlord shall be deemed Tenant's
disapproval of the Acceleration Estimate.

                  3.3.3 LIQUIDATED DAMAGES. IF LANDLORD DOES NOT SUBSTANTIALLY
COMPLETE THE PREMISES BY THE TARGET COMMENCEMENT DATE, THEN TENANT, AS ITS SOLE
AND EXCLUSIVE REMEDY, WILL BE ENTITLED TO RECEIVE LIQUIDATED DAMAGES IN AN
AMOUNT EQUAL TO THE AMOUNT SET FORTH IN ITEM 8 OF THE BASIC TERMS FOR EACH DAY
OF DELAY BETWEEN THE TARGET COMMENCEMENT DATE AND THE DATE LANDLORD
SUBSTANTIALLY COMPLETES THE PREMISES. IN THE EVENT OF SUCH A DELAY, TENANT WILL
BE DAMAGED AND WILL BE ENTITLED TO COMPENSATION FOR THOSE DAMAGES. SUCH DAMAGES
WILL, HOWEVER, BE EXTREMELY DIFFICULT AND IMPRACTICAL TO ASCERTAIN BECAUSE THE
PROOF OF THE AMOUNT OF SUCH DAMAGES WILL BE BASED ON OPINIONS OF SUCH DAMAGES,
WHICH CAN VARY IN SIGNIFICANT AMOUNTS, AND IT IS IMPOSSIBLE TO PREDICT AS OF THE
DATE ON WHICH THIS LEASE IS MADE THE AMOUNT OF SUCH DAMAGES. LANDLORD DESIRES TO
LIMIT THE AMOUNT OF DAMAGES FOR WHICH LANDLORD MIGHT BE LIABLE SHOULD LANDLORD
FAIL TO SUBSTANTIALLY COMPLETE THE PREMISES AS AFORESAID. LANDLORD AND TENANT
WISH TO AVOID THE COST AND LENGTHY DELAYS WHICH WOULD RESULT IF TENANT FILED A
LAWSUIT TO COLLECT ITS DAMAGES FOR SUCH FAILURE TO TIMELY DELIVER. THEREFORE, IF
LANDLORD FAILS TO TIMELY SUBSTANTIALLY COMPLETE THE PREMISES AS DESCRIBED ABOVE,
THE FOREGOING AMOUNT OF LIQUIDATED DAMAGES SHALL BE DEEMED TO CONSTITUTE A
REASONABLE ESTIMATE OF TENANT'S DAMAGES UNDER THE PROVISIONS OF SECTION 1671 OF
THE CALIFORNIA CIVIL CODE, AND TENANT'S SOLE AND EXCLUSIVE REMEDY IN THE EVENT
OF A DELAY IN THE SUBSTANTIAL COMPLETION OF THE PREMISES. IN CONSIDERATION OF
THE PAYMENT OF SUCH LIQUIDATED DAMAGES, TENANT WILL BE DEEMED TO HAVE WAIVED ALL
OTHER CLAIMS FOR DAMAGES OR RELIEF AT LAW OR IN EQUITY INCLUDING ANY RIGHTS
TENANT MAY HAVE PURSUANT TO SECTION 1680 OR SECTION 3389 OF THE CALIFORNIA CIVIL
CODE. LANDLORD SHALL PAY SUCH LIQUIDATED DAMAGES TO TENANT WITHIN TEN (10) DAYS
AFTER LANDLORD SUBSTANTIALLY COMPLETES THE PREMISES IN ACCORDANCE WITH THE WORK
LETTER.


           --------                          ------
           LANDLORD                          TENANT




                  3.3.4 EARLY COMPLETION. If (i) Commencement of Construction
occurs after August 1, 1997, and (ii) Tenant approves the Acceleration Estimate
pursuant to Section 3.3.2 above, and (iii) Landlord Substantially Completes the
Premises prior to the Target Commencement Date, Tenant has agreed to pay to
Landlord an incentive fee in an amount equal to the amount set forth in Item 8
of the Basic Terms ("Incentive Fee"). Tenant shall pay the Incentive Fee to
Landlord within ten (10) days after the Substantial Completion of the Premises.

         3.4      EARLY OCCUPANCY. If Tenant enters or occupies the Premises
prior to the Commencement Date

4/17/97                                               Landlord Initials: _______
                                   6                    Tenant Initials: _______

<PAGE>   16

solely for the purpose of preparing the Premises for the conduct of business
thereon and not for the purposes of conducting business thereon, Tenant's entry
and/or occupancy of the Premises shall be subject to all of the provisions of
this Lease and the Work Letter with the exception of the payment of Base Monthly
Rent and Additional Rent, which obligations shall commence as of the
Commencement Date. If requested by Landlord, Tenant shall execute a hold
harmless agreement in a form prepared by Landlord. Early occupancy of the
Premises shall not advance the expiration date of this Lease. Landlord shall
have the right to charge Tenant for any utility or other costs incurred by
Tenant during such early occupancy period.

         3.5      OPTION(S) TO EXTEND TERM. Tenant shall have the options to
extend ("Extension Option") the Term as set forth in the Basic Terms (as
exercised, each is an "Extension Term"), on the following terms and conditions:

                  3.5.1    EXTENSION NOTICE. Tenant's option to extend the Term
shall be subject to satisfaction of each of the following conditions precedent,
which are solely for the benefit of Landlord:

                           3.5.1.1  Each Extension Option shall be exercised by
written notice ("Extension Notice") delivered by Tenant to Landlord not sooner
than eighteen (18) months and not later than fifteen (15) months prior to the
then scheduled end of the Term ("Extension Deadline"); and

                           3.5.1.2  The Lease shall be in effect and Tenant
shall not be in default under any of Sections 15.2.1, 15.2.2, 15.2.3, 15.2.4, or
15.2.6, or any material default under Section 15.2.5 (beyond any applicable
period of cure) both on the day of the Extension Notice and on the last day of
the Term.

                  3.5.2    BASE MONTHLY RENT DURING EXTENSION. In the event the
Term is extended following exercise by Tenant of an Extension Option, then all
of the terms, covenants and conditions of the Lease shall remain in full force
and effect, except that Base Monthly Rent to be applicable during the Extension
Term shall be adjusted to the Base Monthly Rent During Extensions as described
in Item 9 of the Basic Terms and as further described below.

                           3.5.2.1  As part of the Extension Notice, Tenant
shall notify Landlord of Tenant's proposed Base Monthly Rent During Extension
for the first Lease Year of such Extension Term, which proposal shall be based
on Tenant's good faith estimate of the Fair Market Rent. Landlord shall have
fifteen (15) days after receipt of Tenant's Extension Notice to either accept
Tenant's proposed Base Monthly Rent During Extension for the first Lease Year of
such Extension Term or deliver written notice to Tenant of Landlord's proposed
Base Monthly Rent During Extension for the first Lease Year of such Extension
Term. Landlord's failure to respond within such 15-day period shall be deemed
acceptance of Tenant's proposal.

                           3.5.2.2  If Landlord does not initially accept
Tenant's proposal and timely delivers to Tenant written notice of Landlord's
proposed Base Monthly Rent During Extension for the first Lease Year of such
Extension Term, Tenant shall have ten (10) days after receipt thereof to either
accept or reject Landlord's proposal. Tenant's failure to respond within such
10-day period shall be deemed Tenant's acceptance of Landlord's proposal.

                           3.5.2.3  If Tenant timely rejects Landlord's
proposal, the parties shall meet within fifteen (15) days to negotiate and
attempt to agree in good faith on an appropriate Base Monthly Rent During
Extension. If the parties do not agree on a Base Monthly Rent During Extension
within ten (10) days of such meeting, Tenant shall have the right to either
rescind Tenant's Extension Notice (without any further right or obligation to
extend the Term of this Lease) or elect to send the matter of the Base Monthly
Rent During Extension for the first Lease Year of such Extension Term to
arbitration. If Tenant fails to deliver written notice to Landlord of Tenant's
election within such ten (10) day period, Tenant shall be deemed to have elected
to send the matter of the Base Monthly Rent During Extension for the first Lease
Year of such Extension Term to arbitration. Such arbitration shall be conducted
in San Diego, California, within thirty (30) days after Tenant makes such
election (or is deemed to have made such election) pursuant to the then
applicable Commercial Arbitration Rules of the American Arbitration Association;
provided, however, that the decision of any such arbitration shall be expressly
limited to selecting either Landlord's proposal or Tenant's proposal to be
submitted to the arbitration at the commencement of such arbitration of the Base
Monthly Rent During Extension for the first Lease Year of such Extension Term as
most nearly satisfying the requirement of

4/15/97                                               Landlord Initials: _______
                                   7                    Tenant Initials: _______

<PAGE>   17

this Lease. Tenant's election to send the matter to arbitration shall be
Tenant's binding commitment to occupy the Premises during said Extension Term
and pay Base Monthly Rent during Extension as determined by the arbitration. The
cost of the arbitration, which costs shall include fees charged by the
arbitrators, attorneys' fees and expert or consultant fees, shall be paid by the
party whose proposal was not selected.

                      ARTICLE 4 - RENTAL AND OTHER PAYMENTS

         4.1 BASE MONTHLY RENT. From and after the Commencement Date, Tenant
shall pay to Landlord, in advance, on the first day of each and every calendar
month during the Lease Term, the Base Monthly Rent. The Base Monthly Rent for
any fraction of a month at the beginning of the Lease Term will be prorated.
Payment of the Base Monthly Rent, Additional Rent and all other charges deemed
to be Rent under this Lease shall be without prior notice, deduction, offset or
demand, shall be in lawful money of the United States of America and shall be
made at the address set forth for Landlord in the Basic Terms or at such other
place as Landlord may direct. Base Monthly Rent payable for any period of less
than one (1) month shall be prorated based upon a thirty (30) day month. Tenant
shall pay to Landlord as prepaid Base Monthly Rent, immediately upon execution
of this Lease (in addition to the security deposit required), the amount
specified in the Basic Terms, which sum shall be applied to the first calendar
month of the Lease Term for which payment of Base Monthly Rent is due; provided,
however, that the Option Consideration shall be credited against Tenant's
obligation to deliver such prepaid Base Monthly Rent.

         4.2 INTEREST ON PAST DUE OBLIGATIONS. Any amount owed by Tenant to
Landlord which is not paid when due shall bear interest from the date which is
five (5) days after the due date at the Lease Interest Rate but if such Lease
Interest Rate exceeds the maximum interest rate permitted by law, such Lease
Interest Rate shall be reduced to the highest rate allowed by law under the
circumstances. Interest shall not be payable on late charges to be paid by
Tenant under this Lease. The payment of interest on such amounts shall not
excuse or cure any default by Tenant under this Lease and the parties agree that
such amounts are a reasonable estimate of the costs Landlord will incur as a
result of its loss of the use of its money due to such late payment by Tenant.

         4.3 LATE CHARGES. Tenant's failure to pay any Rent promptly may cause
Landlord to incur unanticipated costs. The exact amount of such costs are
impractical or extremely difficult to ascertain. Such costs may include, but are
not limited to, processing and accounting charges and late charges which may be
imposed on Landlord under any mortgage or trust deed encumbering the Premises.
Therefore, if Landlord does not receive any Rent payment within five (5) days
after it becomes due, Tenant shall pay Landlord a late charge in the amount
specified in the Basic Terms. The parties agree that such late charge represents
a fair and reasonable estimate of the costs Landlord will incur by reason of
such late payment. Acceptance of such late charge by Landlord shall, in no
event, constitute a waiver of Tenant's default with respect to such overdue
amount. The late charge shall be deemed Rent and the rights to require it shall
be in addition to all of Landlord's rights and remedies hereunder or at law and
shall not be construed as liquidated damages or as limiting Landlord's remedies
in any manner.

         4.4 SECURITY DEPOSIT; ADDITIONAL SECURITY AND LOANS

                  4.4.1 DEPOSIT OF FUNDS. Upon the execution of this Lease,
Tenant shall deposit with Landlord a cash security deposit ("Security Deposit")
in the amount set forth in the Basic Terms. Landlord may, but shall not be
obligated to, apply all or part of the Security Deposit to any unpaid Rent or
other charges due from Tenant or to cure any other defaults of Tenant. If
Landlord uses any part of the Security Deposit, Tenant shall restore the
Security Deposit to its full amount within ten (10) days after Landlord's
written request. Tenant's failure to do so shall be a default under this Lease.
Interest shall accrue on the Security Deposit in Tenant's favor at a rate equal
to the then average rate given by San Diego, California banks for three-month
certificates of deposit, and shall become part of the Security Deposit. Landlord
shall not be required to keep the Security Deposit separate from its other
accounts and no trust relationship is created with respect to the Security
Deposit.

                  4.4.2 RETURN OF SECURITY DEPOSIT. Provided that Tenant has not
been in default of its obligations under this Lease more than three (3) times,
Landlord shall return the Security Deposit to Tenant on the date which is the
later of three (3) Lease Years after the Commencement Date, or the date when
Tenant is not then in default under

4/15/97                                               Landlord Initials: _______
                                   8                    Tenant Initials: _______

<PAGE>   18

this Lease. If Tenant has had more than three (3) defaults under this Lease,
whether or not such defaults have been cured, then Landlord shall retain the
Security Deposit for the Term.

                  4.4.3 ADDITIONAL SECURITY AND LOANS. Tenant shall deliver to
Landlord or, at Landlord's request, to Landlord's construction and/or permanent
lender, additional security in an amount up to the first (1st) Lease Year's Base
Annual Rent ("Additional Security"). The Additional Security shall be held and
used by Landlord in the same manner and for the same purposes as the Security
Deposit. The Additional Security may be cash or a letter of credit (at Tenant's
election) or other financial instrument reasonably acceptable to Landlord. If
the Additional Security is a letter of credit, it shall be issued in favor of
Landlord.

                           4.4.3.1  Landlord will determine the amount of such
Additional Security as soon as reasonably possible. Any expense incurred by
Tenant in the obtaining and maintaining of such Additional Security shall be the
sole cost and expense of Tenant; provided, however, that Tenant shall not be
required to incur any such expense in excess of Seventy-Five Thousand Dollars
($75,000) during the Term of the Lease. If such costs or expenses exceed
Seventy-Five Thousand Dollars ($75,000), Tenant shall still be required to
deliver the Additional Security as long as Landlord pays any excess costs or
expenses (which shall not exceed reasonable and competitive costs and expense
for such services).

                           4.4.3.2  Tenant may, but shall not be obligated to,
submit to Landlord concepts, ideas or opportunities for Landlord's permanent
financing of the Building. Landlord may, but shall not be obligated to, utilize
any or all of such concepts, ideas or opportunities. In the event that Landlord
does utilize a concept, idea or opportunity proposed or arranged by Tenant for
Landlord's permanent financing of the Building and such event results in lower
costs to Landlord of such financing than what Landlord had otherwise arranged,
Landlord will reduce the Base Monthly Rent by amortizing the amount of such
lower costs over the remaining initial Lease Term.

                  4.4.4 TRANSFER OF SECURITY DEPOSIT AND ADDITIONAL SECURITY.
Landlord may deliver the funds deposited hereunder by Tenant to a purchaser of
Landlord's interest in the Premises, in the event that such interest be sold;
and thereupon Landlord shall be discharged from any further liability with
respect to such Security Deposit and Additional Security.

                   ARTICLE 5 - OTHER CHARGES PAYABLE BY TENANT

         5.1 RENT. All Rent under this Lease shall, unless this Lease expressly
provides otherwise, be paid with the next installment of Base Monthly Rent
falling due.

         5.2 COMMON AREA MAINTENANCE CHARGES. Landlord shall operate, maintain,
manage and repair the Building, Project and Common Area in a neat, orderly
condition, reasonably equivalent to that found in projects in San Diego County
similar to the Building.

                  5.2.1 TENANT TO BEAR PROPORTIONAL SHARE OF COMMON AREA
MAINTENANCE CHARGES. Tenant agrees to pay to Landlord, as part of Excess
Operating Costs Rent, Tenant's Proportional Share of the Common Area Maintenance
Charges and certain charges for the Site Amenities as set forth below which are
allocable to the Lease Term.

                  5.2.2 LANDLORD'S COMMON AREA MAINTENANCE CHARGES. For the
purpose of this Lease, the term "Common Area Maintenance Charges" means the
total cost and expense incurred by Landlord in operating, maintaining, managing
and repairing the Building, Project and the Common Area, including, without
limitation, costs and expenses for the following: servicing, maintenance,
replacement and repair of heating/ventilation and air-conditioning systems
(amortized over an appropriate industry standard useful life); gardening and
landscaping; maintenance and repair of roof; pest extermination services;
janitorial services for the Premises; utilities, water and sewer charges (other
than with respect to utilities separately metered and paid directly by Tenant);
maintenance of parking areas; fees, charges and other costs (including, without
limitation, consulting, accounting and legal fees, but excluding legal and
accounting fees directly attributable to other tenants) reasonably necessary to
manage the Building


4/15/97                                               Landlord Initials: _______
                                   9                    Tenant Initials: _______

<PAGE>   19

and the Project (including a fee to Landlord for management of the Project;
costs of compliance with any and all governmental laws, ordinances, and
regulations applicable to the Building or Project which were not imposed as of
the Commencement Date; installation, maintenance and replacement of signs
identifying the Building and Project (other than Tenant's signs whose
maintenance is paid for by Tenant); charges under any Declarations; Property
Taxes for the Building and Project; Insurance Charges for the Building and
Project; all personal property taxes levied on or attributable to personal
property used in connection with the Common Area; rental or lease payments paid
by Landlord for rented or leased personal property used in the operation or
maintenance of the Building Common Area; fees for required licenses and permits
(except as set forth in Work Letter); repairing, resurfacing, repaving,
maintaining, painting, lighting, cleaning, refuse removal, security (if any),
and similar items; reasonable and customary operating reserves; and the
amortized costs (as reasonably determined by Landlord over an appropriate
industry standard useful life) to repair, maintain or install capital
improvements. Notwithstanding the foregoing, Tenant's Proportional Share of
Common Area Maintenance Charges due to Landlord's management fee shall not
exceed four percent (4%) of the first (1st) Lease Year's Base Annual Rent
throughout the Lease Term. Project Operating Expenses would include the
operating expenses for the Site Amenities; provided, however, that unless and
until the Project includes buildings and occupants with rights to use the Site
Amenities in addition to the Building and Tenant (at which time Tenant's
obligation shall be determined by Tenant's Site Amenities Proportional Share),
Tenant shall be liable to Landlord for all of the costs and expenses of
operating, maintaining, managing and repairing the Site Amenities, except
twenty-seven and one-half percent (27.5%) of such costs and expenses shall be
deemed included within the Operating Costs Allowance. Landlord may cause any or
all of such services to be provided by an independent contractor.

                  5.2.3 EXCLUSIONS FROM COMMON AREA MAINTENANCE CHARGES.
Notwithstanding anything in this Lease to the contrary, the term "Common Area
Maintenance Charges" (and hence Operating Costs) shall in no event include any
of the following: (i)any ground lease rental; (ii)costs incurred by Landlord for
the repair of damage to the Building or the Common Area, to the extent that
Landlord is reimbursed by insurance proceeds; (iii)advertising and promotional
expenditures for the Building or the Common Area, and marketing costs,
including, without limitation, leasing commissions, attorneys' fees in
connection with the negotiation and preparation of letters of intent, leases,
subleases and/or assignments with present or prospective tenants or other
occupants in the Building; (iv)electric power costs for which any tenant
directly contracts at the local public service company or for which any tenant
is separately metered or submetered and pays Landlord directly; or (v)the cost
of any utility services obtained by Tenant.

                  5.2.4 REPAIRS DUE TO MISUSE. Notwithstanding any provision of
this Lease to the contrary, Tenant shall be responsible for all of Landlord's
costs and expenses due to repairs to the Premises, Site Amenities or Project
which are made necessary by any misuse or neglect by (a) Tenant or any of its
agents, employees, contractors, or subtenants or (b) any visitors, patrons,
guests or invitees of Tenant while in or upon the Premises.

         5.3 PAYMENT OF EXCESS OPERATING COSTS RENT. The parties acknowledge
that Tenant is leasing the Premises on a modified gross (net of electricity)
basis. Tenant shall pay Excess Operating Costs Rent, in advance, in monthly
installments on the first day of each month during the Lease Term (prorated for
any fractional month). Landlord shall provide to Tenant a written notice of
Landlord's budget showing a reasonable estimate of the Excess Operating Costs
Rent, approximately thirty (30) days prior to the commencement of each calendar
year or portion thereof after the expiration of the first (1st) Lease Year
(which amount may be re-estimated from time to time by Landlord during the
calendar year) and an estimate of Tenant's share thereof for the ensuing year or
portion thereof. Tenant shall pay to Landlord, monthly in advance, one-twelfth
(1/12th) of the estimate of Excess Operating Costs Rent (or, if less than a full
calendar year has been estimated, then the monthly pro rata share).

                  5.3.1 PREVIOUS CHARGES. If, for any reason, Landlord is unable
to provide to Tenant the estimate of the Excess Operating Costs Rent at least
thirty (30) days prior to the commencement of any calendar year during the Lease
Term, then Tenant shall continue to pay monthly the same amount of Excess
Operating Costs Rent as was applicable for the most recent previous month
("Previous Charges") until thirty (30) days after receipt of such estimate at
which time Tenant shall commence paying as of the first day of the first
calendar month after delivery of such new estimate, the new estimated Excess
Operating Costs Rent. Subject to the foregoing, Tenant shall also pay, together

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with its next installment, the difference between the Previous Charges and the
amount of the new estimated Excess Operating Costs Rent for such preceding
months. Any delay by Landlord in delivering the new estimated Excess Operating
Costs Rent shall not be deemed a waiver of any such Excess Operating Costs Rent.

                  5.3.2 YEAR-END ADJUSTMENTS. Within one hundred twenty (120)
days after the end of each calendar year during the Lease Term, Landlord shall
provide Tenant with a written statement showing in reasonable detail the actual
Excess Operating Costs Rent for such year. Landlord and Tenant shall, within
thirty (30) days thereafter, make any payment or credit necessary to bring
Tenant's previously estimated Excess Operating Costs Rent into conformance with
the actual Excess Operating Costs Rent as determined by Landlord. Any amount due
Tenant as a credit shall be credited against installments next coming due from
Tenant under the Lease and any amounts owed to Landlord shall be paid with the
next installment of Base Monthly Rent; provided, however, that if the Lease Term
has terminated and no other amounts are then owing to Landlord from Tenant
pursuant to this Lease, any such amount due Tenant or Landlord shall be remitted
to the party owed such amount within thirty (30) days of the date Landlord
calculates and notifies Tenant of the amount of such adjustment.

                  5.3.3 AUDIT. Landlord shall retain its records regarding
Common Area Maintenance Charges for a period of at least one (1) year following
the final billing for the calendar year in question. At any time during such one
(1) year period, upon reasonable advance written notice to Landlord, but not
more frequently than once in any calendar year, Tenant shall have the right to
audit all of Landlord's or Landlord's agent's records pertaining to Common Area
Maintenance Charges by a representative of Tenant's choice. If such audit
reveals that Landlord's annual statement was incorrect, any over-billing
discovered in the course of such audit shall be refunded to Tenant within thirty
(30) days of Landlord's receipt of a copy of the audit, unless Landlord disputes
the audit, and any underbilling shall be paid by Tenant to Landlord within
thirty (30) days of the audit. In the event that any overbilling exceeds the
amount actually due from Tenant for the year by three percent (3%) or more, then
Landlord shall reimburse Tenant for the reasonable costs of the audit. If
Landlord disputes the results of Tenant's audit, Landlord and Tenant shall
attempt to resolve such dispute in good faith. If Landlord and Tenant are unable
to do so within thirty (30) days, then Landlord shall commission a second audit
by an independent accounting firm selected by Landlord. The results of such
second audit shall be deemed conclusive as to any such dispute. Landlord shall
pay the cost of such second audit and Tenant's audit unless such second audit
reveals amounts actually due from Tenant for the year are within the three
percent (3%) noted above, in which event Tenant shall pay for the second audit
as well as Tenant's audit. In any event, Tenant shall continue to pay all Rent
and Excess Operating Costs Rent as otherwise provided by this Lease until the
dispute is resolved or the results of the second audit are available.

         5.4 PERSONAL PROPERTY TAXES. Tenant shall pay prior to delinquency all
taxes charged against trade fixtures, furnishings, equipment or any other
personal property belonging to Tenant. Tenant shall use its best efforts to have
such personal property taxed separately from the Premises. If any of Tenant's
personal property is taxed with the Premises or Project, Tenant shall pay
Landlord the taxes for the personal property within fifteen (15) days after
Tenant receives a written statement from Landlord for such personal property
taxes.

                           ARTICLE 6 - USE OF PROPERTY

         6.1 PERMITTED USES. Tenant shall use the Premises only for the
Permitted Uses set forth in the Basic Terms and for no other use or purpose
without the prior written consent of Landlord, which consent may be withheld in
the sole, absolute and/or arbitrary discretion of Landlord.

         6.2 MANNER OF USE.

                  6.2.1 INTERFERENCE WITH USE/NUISANCE. Tenant shall not do or
permit anything to be done in or about the Premises which will in any way
obstruct or interfere with or infringe on the rights of other occupants or
customers of the Project, or injure or annoy them, or use or allow the Premises
to be used for any improper, immoral, or objectionable purposes; nor shall
Tenant cause, maintain or permit any nuisance in, on or about the Premises or
commit or suffer to be committed any waste in, on or about the Premises. Tenant
shall keep the interior of the Premises (except for Landlord's obligation to
maintain the Common Areas), and every part thereof, in a clean

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condition, free from any noises, vibrations, music volumes, lighting (including,
without limitation, strobe lighting), speakers, videos, odors or nuisances
deemed objectionable by Landlord, and shall comply with all health and police
regulations in all respects. Tenant shall not display or sell merchandise, or
place carts, portable signs, devices or any other objects, outside the defined
exterior walls or roof and permanent doorways of the Premises or in corridors,
without the prior written consent of Landlord.

                  6.2.2 VIOLATION OF LAW/INSURANCE PROVISIONS. Tenant shall not
use or occupy the Premises in violation of any law, ordinance, regulation or
requirement or other directive of any federal, state or local governmental or
quasi-governmental authority having or exercising jurisdiction over the Project.
Tenant shall, at its sole cost and expense, fully comply with all laws,
ordinances, regulations, requirements and other directives of any federal,
local, governmental or quasi-governmental authority having jurisdiction over the
Premises and the Project, including, without limitation, operational and other
requirements imposed upon either owners or operators of any public accommodation
under the Americans with Disabilities Act 42 U.S.C. 12101 et. seq., and shall
immediately discontinue any use of the Premises which is declared by any
governmental authority having or exercising jurisdiction thereover to be a
violation of any law, ordinance, regulation or directive. If requested by
Landlord, Tenant shall provide evidence satisfactory to Landlord of Tenant's
compliance. Tenant shall not do or permit to be done anything which will
(i)increase the premium of any insurance policy covering the Premises or the
Project and/or the property located therein; (ii)cause a cancellation of or be
in conflict with any such insurance policies; or (iii)result in a refusal by
insurance companies in good standing to issue or continue any such insurance in
amounts satisfactory to Landlord. Tenant shall, at Tenant's expense, comply with
all rules, orders, regulations and requirements of insurers and of the American
Insurance Association or any other organization performing a similar function.
Tenant shall promptly, upon demand, reimburse Landlord for any additional
premium charges for such policy or policies caused by reason of Tenant's failure
to comply with the provisions of this Section. Additionally, after Substantial
Completion of the Premises pursuant to the Work Letter, Tenant agrees at its
sole cost to install any improvements, changes or alterations in the Premises
authorized in writing by Landlord and required by any governmental authority as
a result of Tenant's proposed use of the Premises or its manner of operation
thereunder, and Tenant's failure to perform same shall constitute a default by
Tenant hereunder.

                  6.2.3 PERMITS. Except as set forth in the Work Letter, Tenant
shall obtain and pay for all permits required for Tenant's occupancy of the
Premises and shall promptly take all substantial and non-substantial actions
necessary to comply with all applicable statutes, ordinances, rules,
regulations, orders and requirements regulating the use by Tenant of the
Premises, including the Occupational Health and Safety Act.

         6.3 RULES AND REGULATIONS. Tenant shall comply with the Rules and
Regulations and any amendments, modifications and/or additions thereto as may
hereafter be adopted and published by Landlord. Landlord shall not be liable to
Tenant for any violation of such Rules and Regulations or the breach in any
provision in any lease by any other tenant or other party. In the event of any
inconsistency between the Rules and Regulations and this Lease, this Lease shall
prevail.

         6.4 LANDLORD'S ACCESS. Landlord and its agents, independent contractors
and designated representatives, may enter the Premises at all reasonable times
to post notices of non-responsibility, to make repairs and/or to show the
Premises to holders of any encumbrances, potential buyers, mortgagees, investors
or tenants or other parties, or for any other purpose Landlord deems reasonably
necessary. Landlord shall give Tenant prior notice of such entry, except in the
case of an emergency, in which case no prior notice need be given. Any entry to
the Premises by Landlord in the event of an emergency shall not, under any
circumstances, be construed or deemed to be a forcible or unlawful entry onto
the Premises or to be an eviction of Tenant from the Premises or any part
thereof. Landlord may place customary "For Lease" signs on the Premises during
the last one hundred eighty (180) days of the Lease Term.

         6.5 QUIET POSSESSION. If Tenant pays the Rent and complies with all
other terms of this Lease, Landlord assures Tenant that it may occupy and enjoy
the Premises for the full Lease Term, subject to the provisions of this Lease
and to any mortgages or deeds of trust encumbering the Project.

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                         ARTICLE 7 - HAZARDOUS MATERIALS

         7.1 PROHIBITION. Tenant shall not cause or permit any Hazardous
Materials to be brought upon, kept, or used in connection with the Premises or
Project by Tenant, its agents, employees, contractors or invitees, in a manner
or for a purpose prohibited by or which could result in liability under any
applicable law, regulation, rule or ordinance, including without limitation, the
Hazardous Materials Laws. Tenant shall, at its own expense, at all times and in
all respects comply with all Hazardous Materials Laws, including, without
limitation, any Hazardous Materials Laws relating to industrial hygiene,
environmental protection or the use, analysis, generation, manufacture, storage,
disposal or transportation of any Hazardous Materials.

                  7.1.1 USE. Tenant shall, at its own expense, procure, maintain
in effect and comply with all conditions of any and all permits, licenses and
other governmental and regulatory approvals relating to the presence of
Hazardous Materials within, on, under or about the Premises or required for
Tenant's use of any Hazardous Materials in or about the Premises in conformity
with all applicable Hazardous Materials Laws and prudent industry practices
regarding management of such Hazardous Materials. Upon termination or expiration
of the Lease, Tenant shall, at its own expense, cause all Hazardous Materials
placed in or about the Premises or Project by Tenant or at Tenant's direction to
be removed from the Premises and Project and transported for use, storage or
disposal in accordance and compliance with all applicable Hazardous Materials
Laws.

                  7.1.2 NORMAL USAGE. Landlord recognizes and agrees that Tenant
may use materials in normal quantities that are applicable to general office use
and that such use by Tenant shall not be deemed a violation of this Section, so
long as the levels are not in violation of any Hazardous Materials Laws.
Landlord acknowledges that it is not the intent of this Article 7 to prohibit
Tenant from operating its business as described in this Lease. Tenant may
operate its business according to the custom of the industry so long as the use
or presence of Hazardous Materials is strictly and properly monitored according
to all applicable governmental requirements.

         7.2 DISCLOSURE AND WARNING OBLIGATIONS. Tenant shall comply with all 
laws, ordinances and regulations in the State where the Premises is located
regarding the disclosure of the presence or danger of Hazardous Materials.
Tenant acknowledges and agrees that all reporting and warning obligations
required under the Hazardous Materials Laws are the sole responsibility of
Tenant, whether or not such Hazardous Materials Laws permit or require Landlord
to provide such reporting or warnings, and Tenant shall be solely responsible
for complying with Hazardous Materials Laws regarding the disclosure of, the
presence or danger of Hazardous Materials, including, without limitation, all
notices or other requirements under California Health and Safety Code Section
25915 et. seq., and 25249.5 et. seq. and California Code of Regulations Section
12000 et. seq.

         7.3 NOTICE OF ACTIONS; HAZARDOUS MATERIALS LIST. Tenant shall
immediately notify Landlord in writing of (a) any enforcement, cleanup, removal
or other governmental or regulatory action instituted, completed or threatened
pursuant to any Hazardous Materials Laws; (b)any claim made or threatened by any
person against Landlord, or the Premises or the Project, relating to damage,
contribution, cost recovery, compensation, loss or injury resulting from or
claimed to result from any Hazardous Materials; (c)any reports made to any
environmental agency arising out of or in connection with any Hazardous
Materials in, on or about the Premises or with respect to any Hazardous
Materials removed from the Premises, including, any complaints, notices,
warnings, reports or asserted violations in connection therewith; and (d)any
release of a Hazardous Material that Tenant knows or has reason to believe has
or will come to be released or located within, on, under or about the Premises
or the Project. Tenant shall also provide to Landlord, as promptly as possible,
and in any event within five (5) Business Days after Tenant first receives or
sends the same, copies of all claims, reports, complaints, notices, warnings or
asserted violations relating in any way to the Premises or Tenant's use thereof.
Upon written request of Landlord (to enable Landlord to defend itself from any
claim or charge related to any Hazardous Materials Law), Tenant shall promptly
deliver to Landlord notices of hazardous waste manifests reflecting the legal
and proper disposal of all such Hazardous Materials removed or to be removed
from the Premises. All such manifests shall list the Tenant or its agent as a
responsible party and in no way shall attribute responsibility for any such
Hazardous Materials to Landlord. As a material inducement to Landlord to allow
Tenant to use Hazardous Materials in connection with its business, Tenant agrees
to deliver to Landlord prior to the Commencement Date, a list identifying each
type of Hazardous Material to be present on the

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Premises and setting forth any and all governmental approvals or permits
required in connection with the presence of Hazardous materials on the Premises
("Hazardous Materials List"). Tenant shall deliver to Landlord an updated
Hazardous Materials List at least once a year and shall also deliver an updated
list before any new Hazardous Materials are brought onto the Premises or on or
before the date Tenant obtains any additional permits or approvals.

         7.4 HAZARDOUS MATERIALS INDEMNITY. Tenant shall indemnify, defend (by
counsel reasonably acceptable to Landlord), protect, and hold Landlord and each
of Landlord's Indemnitees free and harmless from and against any and all claims,
liabilities, penalties, forfeitures, losses and/or expenses, attorneys' fees,
consultant fees and expert fees, judgments, administrative rulings or orders,
fines, costs for death of or injury to any person or damage to any property
whatsoever (including, without limitation, water tables, sewer systems and
atmosphere), arising from, or caused or resulting, in whole or in part, directly
or indirectly, by the release, presence or discharge in, on, under or about the
Premises or Project of any Hazardous Materials caused by or arising from the
activities of Tenant, Tenant's agents, employees, licensees, or invitees, or
from the transportation or disposal of any Hazardous Materials to or from the
Premises or Project by Tenant, Tenant's agents, employees, licensees or invitees
or at Tenant's direction, or by Tenant's failure to comply with any Hazardous
Materials Laws, or from Tenant's failure to provide adequate disclosures or
warnings required by the Hazardous Materials Laws, or from any breach by Tenant
of the obligations in this Article7. Tenant's indemnification obligations
hereunder shall include, without limitation, and whether foreseeable or
unforeseeable, all costs of any required or necessary Hazardous Materials
management plan, investigation, repairs, cleanup or detoxification or
decontamination of the Premises or Project, and the presence and implementation
of any closure, remedial action or other required plans in connection therewith,
and shall survive the expiration of or early termination of the Lease Term.

         7.5 ASSIGNMENT AND SUBLETTING. If (i) any anticipated use of the
Premises by any proposed assignee or sublessee involves the generation, storage,
use, treatment or disposal of Hazardous Materials in a manner or for a purpose
prohibited by any governmental agency or authority, (ii) the proposed assignee
or sublessee has been required by any prior landlord, lender or governmental
authority to take remedial action in connection with Hazardous Material
contaminating a property if the contamination resulted from such party's action
or use of the property in question or (iii) the proposed assignee or sublessee
is subject to an enforcement order issued by any governmental authority in
connection with the use, disposal or storage of a Hazardous Material, it shall
not be unreasonable for Landlord to withhold its consent to an assignment or
subletting to such proposed assignee or sublessee. Landlord may require a
written statement from the proposed assignee or sublessee attesting to such
matters.

         7.6 ENVIRONMENTAL TESTS AND AUDITS. Tenant shall not perform or cause
to be performed any Hazardous Materials surveys, studies, reports or
inspections, relating to the Premises or Project, without obtaining Landlord's
prior written consent. At any time prior to the expiration of the Lease Term, if
Landlord has a reasonable basis to believe that Hazardous Materials are present
in, on or about the Premises in violation of any Hazardous Materials Laws,
Landlord shall have the right to enter upon the Premises in order to conduct
appropriate tests and to deliver to Tenant the results of such tests to
demonstrate that levels of any Hazardous Materials in excess of permissible
levels has occurred as a result of Tenant's use of the Premises. Such testing
shall be at Tenant's expense if Landlord has a reasonable basis for suspecting
and confirms the presence of Hazardous Materials in the soil or surface or
ground water in, on, under, or about the Premises, or the Project which has been
caused by or resulted from the activities of Tenant, its agents, employees,
contractors or invitees.

         7.7 LEASE "AS IS". Subject to the express provisions of this Lease
(including the Work Letter), Tenant, in entering into this Lease, is leasing the
Premises "As Is" and is relying solely upon its own inspections, investigations
and analyses of the Premises relating to Hazardous Materials. Tenant further
acknowledges Tenant is not relying in any way upon any representations,
statements, warranties, studies, reports, or other information of Landlord or
its representatives, whether oral or written, of any nature whatsoever regarding
any Hazardous Materials.

         7.8 SURVIVAL. The respective rights and obligations of Landlord and
Tenant under this Article 7 shall survive the expiration or termination of this
Lease. During any period of time employed by Tenant after the termination of
this Lease to complete the removal from the Premises or Project or remediation
of any such Hazardous Materials, Tenant shall continue to pay the full rental in
accordance with this Lease, which rental shall be prorated

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<PAGE>   24

daily.

                              ARTICLE 8 - UTILITIES

         8.1 PAYMENT AND ARRANGEMENT. Tenant shall arrange for and pay, directly
to the appropriate supplier, the cost of all electric power and telephone
supplied to the Premises. In the event the Premises are less than the entire
Building, and if any utilities to the Premises are jointly metered and such
utilities are not otherwise included as a Common Area Maintenance Charge,
Landlord shall determine, and Tenant shall pay, Tenant's share of the monthly
costs of such utilities. Tenant's share shall be determined by the ratio of the
rentable square footage of the Premises as compared to the rentable square
footage of all the leased and occupied property within the Project subject to
the common metering. Landlord shall have the right to bill Tenant for such
amounts on an estimated basis, in which case, such estimated statements shall be
delivered to Tenant and Tenant shall pay such amounts to Landlord concurrently
with its payment of Base Monthly Rent. The Tenant shall pay such charges, as
Rent, within five (5) days of notification of the amount by the Landlord.
Landlord reserves the right to require Tenant to install and maintain, at
Tenant's sole expense, separate meters for any public utility servicing the
Premises for which a separate meter is not presently installed.

         8.2 INTERRUPTION OF SERVICES AND UTILITIES. Landlord shall not be
liable for, and Tenant shall not be entitled to any reduction of, the Base
Monthly Rent, Additional Rent or any other Rent payable hereunder by reason of
Landlord's failure to make available any of the services or utilities described
in this Lease, when such failure or interruption is caused by acts of God,
accident, breakage, repairs, strikes, lockouts or other labor disturbances or
disputes, necessary repairs, installations, construction and expansion,
non-payment of utility charges due from Tenant, or by reason of governmental
regulation, statute, ordinance, restriction or decree or any other similar
cause. Notwithstanding the foregoing, Landlord shall be responsible for the
consequences of Landlord's own negligence or intentional misconduct.
Furthermore, Landlord shall not be liable under any circumstances for a loss of,
or injury to, property or for injury to, or interference with, Tenant's
business, including, without limitation, loss of profits, however occurring,
through or in connection with or incidental to a failure to furnish any of the
foregoing services or utilities. Tenant, as a material part of the consideration
to be rendered to Landlord, hereby waives all claims against Landlord for the
foregoing damages from any cause arising at any time.

         8.3 OPERATING HOURS. Normal operating hours for the Building and
included within the Operating Costs Allowance are 7:00 a.m. to 6:00 p.m.
weekdays and Saturday from 8:00 a.m. to 1:00 p.m. Tenant shall be permitted
heating/ventilation/air conditioning ("HVAC") service at other hours for which
Tenant shall pay at a rate equal to Seven Dollars ($7.00) per hour of usage
(subject to a reasonable adjustment based on actual design of the HVAC system
pursuant to the Work Letter), increased in proportion to the increase of the CPI
on each annual anniversary of the Lease Date. Landlord shall meter and Tenant
shall pay for such operation of the HVAC systems beyond the normal sixty hours
weekly usage on a quarterly basis.

                 ARTICLE 9 - PARKING AND CONTROL OF COMMON AREAS

         9.1 CONTROL OF COMMON AREAS BY LANDLORD. All Common Areas, the Site
Amenities, and all automobile parking areas, driveways, entrances and exits
thereto, and other facilities furnished by Landlord in or near the Project,
shall at all times be subject to the exclusive control and management of
Landlord or Landlord's designated agent. Landlord shall have the right to
construct, maintain and operate lighting facilities on all said areas and
improvements; to police the same; from time to time to change the area, level,
location and arrangement of parking areas and other facilities hereinabove
referred to; to restrict parking by tenants, their officers, agents and
employees to employee parking areas; to close all or any portion of said areas
or facilities to such extent as may, in the opinion of Landlord, be legally
sufficient to prevent a dedication thereof or the accrual of any rights to any
person or the public therein; to close temporarily all or any portion of the
parking areas or facilities; to discourage non-customer parking; to convert such
areas into leasable areas; to construct additional parking facilities and to do
and perform such other acts in and to said areas and improvements as, in the use
of good business judgment, the Landlord shall determine to be advisable with a
view to the improvement of the convenience and use thereof by tenants, their
officers, agents, employees and customers, provided that such changes shall not
reduce the number of parking spaces below the

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<PAGE>   25

number required as stated below. No such change shall entitle Tenant to an
abatement of Rent. Tenant will have the nonexclusive use of not less than four
(4) parking spaces per one thousand (1,000) usable square feet of the Premises;
provided, however, that Tenant shall have the right to designate up to twelve
(12) of the foregoing parking spaces immediately adjacent to the Building as
reserved for the Tenant, with the remainder of the parking spaces pursuant to
the foregoing calculation to be on a nonexclusive basis.

         9.2 LICENSE. All Common Areas are to be used and occupied under a
license which may be revoked by Landlord in the event of a default by Tenant and
termination of the Lease, and if any such license be revoked, or if the amount
of such areas be diminished, Landlord shall not be subject to any liability nor
shall Tenant be entitled to any compensation or diminution or abatement of Rent,
or shall such revocation or diminution of such areas be deemed constructive or
actual eviction.

               ARTICLE 10 - ALTERATIONS, IMPROVEMENTS AND SIGNAGE

         10.1 CHANGES/ALTERATIONS. Tenant shall not make any alterations,
additions, or changes, including, without limitation, installation of any
permanently attached trade fixtures, exterior signs, exterior machinery, floor
coverings, interior or exterior lighting, plumbing fixtures, shades or awnings
(collectively "Alterations") in and to the Premises or any part thereof without
the prior written consent of Landlord which consent may be withheld in
Landlord's sole and absolute discretion; provided, however, that Tenant may make
nonstructural Alterations that do not affect the electrical, plumbing, heating,
ventilation, air conditioning or other systems of the Premises and that cost
less than $10,000 in any Lease Year without Landlord's consent. Any construction
undertaken in or to the Premises shall be performed in accordance with this
Article and the other obligations of this Lease.

         10.2     MANNER OF CONSTRUCTION.

                  10.2.1 CONDITIONS TO CONSENT. Landlord may impose, as a
condition of its consent to any Alterations or repairs on or about the Premises,
such requirements as Landlord in its reasonable discretion may deem desirable,
including, but not limited to, the requirements that Tenant obtain bonds and
that Tenant utilize for such purposes only contractors, materials, mechanics and
materialmen approved by Landlord, in its sole discretion. Tenant shall construct
such Alterations or repairs in strict conformance with any and all applicable
rules and regulations of Landlord and any federal, state, county or municipal
code or ordinance and pursuant to a valid building permit, issued by the local
governing entity, and obtained at Tenant's sole cost and expense. All fixtures
installed by Tenant shall be new.

                  10.2.2 COST. In any event, a licensed contractor approved by
Landlord shall perform all mechanical, electrical, plumbing, air conditioning,
permanent partition and ceiling tile work, and such work shall be performed at
Tenant's cost. If Landlord's consent is required, Landlord reserves the right to
approve, in Landlord's reasonable discretion, the contractor selected by Tenant
for the completion of any Alterations. In the event Tenant orders any
construction, alteration, decorating or repair work and fails to pay amounts
when due to the contractor or contractors in connection with such items,
Landlord, without any obligation to do so, may pay any such amounts directly to
such contractor or contractors (with a notice to Tenant of such payment) and the
amounts paid by Landlord shall be deemed Rent under this Lease, payable upon
billing therefor.

                  10.2.3 GOOD AND WORKMANLIKE MANNER. All work with respect to
any Alterations or repairs must be done in a good and workmanlike manner and
diligently prosecuted to completion to the end that the Premises shall at all
times be a complete unit except during the period of work. Upon completion of
any Alterations, Tenant agrees to deliver to the Landlord's management office a
copy of the "as built" drawings of the Alterations and record any necessary
notices to evidence completion. In performing the work of any such Alterations,
Tenant shall have the work performed in such manner as not interfere with or to
obstruct the access to the Common Area and to any other tenant of the Project.

         10.3     CONSTRUCTION INSURANCE. Whether or not Landlord's consent is
required, Tenant agrees to obtain, carry and deliver to Landlord prior to the
commencement of any Alterations and maintain in effect until completion of


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                                   16                   Tenant Initials: _______
<PAGE>   26

all Alterations "Builder's All Risk" insurance in an appropriate amount covering
the construction of such Alterations, and such other insurance as Landlord may
require, it being understood and agreed that all of such Alterations shall be
insured by Tenant pursuant to Section11.2.2 of this Lease immediately upon
completion thereof.

         10.4 LIENS. Tenant shall keep the Premises and the Project free from
any mechanics', materialmen's, designer's or other liens arising out of any work
performed, materials furnished or obligations incurred by or for Tenant or any
person or entity claiming by, through or under Tenant. If any such liens are
filed and are not released of record by payment or posting of a proper bond
within ten (10) days after such filing, Landlord may, without waiving its rights
and remedies based on such breach by Tenant and without releasing Tenant from
any obligations hereunder, cause such liens to be released by any means it shall
deem proper, including payment of the claim giving rise to such lien, in which
event all amounts paid by Landlord shall immediately be due and payable by
Tenant as Rent. Tenant hereby indemnifies, protects, defends (with legal counsel
acceptable to Landlord) and holds Landlord and Landlord's Indemnitees, the
Premises and the Project harmless from any liability, cost, obligation, expense
(including, without limitation, reasonable attorneys' fees and expenses), or
claim of any mechanics', materialmen's, design professional's or other liens in
any manner relating to any work performed, materials furnished or obligations
incurred by or for Tenant or any person or entity claiming by, through or under
Tenant. Whether or not Landlord's consent is required, Tenant shall notify
Landlord in writing within fifteen (15) days prior to commencing any Alterations
so that Landlord shall have the right to record and post notices of
non-responsibility or any other notices deemed necessary by Landlord on the
Premises.

         10.5 SIGNAGE. As an Alteration, Tenant shall have the right to have its
name displayed on the Building at a location mutually chosen by Landlord and
Tenant. Any such signage shall also be subject to the requirements of all
government agencies with jurisdiction over the Project, and the Declarations.
Landlord shall use a signage company selected by Tenant and reasonably
acceptable to Landlord. Tenant shall pay all costs of Landlord associated with
installing such signage within ten (10) days of receiving an invoice from
Landlord setting forth such costs. All such signage shall be subject to
Landlord's specifications and approval as to size, graphics and style, which
approval may be withheld in Landlord's reasonable discretion.

                      ARTICLE 11 - INSURANCE AND INDEMNITY

         11.1     INSURANCE TO BE OBTAINED BY LANDLORD.

                  11.1.1 FIRE AND CASUALTY INSURANCE. Landlord shall maintain
during the Lease Term a policy or policies of insurance insuring the Premises
and the Common Area and, at Landlord's election, other portions of the Project,
against all direct physical loss or damage, whether due to fire or other
casualties covered within the classification of fire and extended coverage,
vandalism coverage and malicious mischief, sprinkler leakage, water damage and
special extended coverage. Such coverage shall be for full replacement value,
and may include, at the option of Landlord, the risks of earthquakes and/or
flood damage and additional hazards, a rental loss endorsement and one or more
loss payee endorsements in favor of the holders of any mortgages or deeds of
trust encumbering the interest of Landlord in all or any portion of the Project
or the interest of any ground or underlying lessors in the Project. The costs of
such insurance shall be included as a component of the Common Area Maintenance
Charges.

                  11.1.2 LIABILITY INSURANCE. Landlord shall maintain a
commercial general liability insurance policy, or an equivalent, written on an
occurrence form that includes personal injury coverage, bodily injury, death,
property damage, and advertising injury coverage, insuring against liability
arising out of the ownership, use, or maintenance of the Common Area or the
Project. The initial amount of such insurance shall be Two Million Dollars
($2,000,000) each occurrence/Three Million Dollars ($3,000,000) general
aggregate on a per location basis and Two Million Dollars ($2,000,000) for
personal injury and advertising injury coverage. Landlord may also obtain
umbrella coverage up to Ten Million Dollars ($10,000,000). The costs of all such
insurance shall be included as part of the Common Area Maintenance Charges.

         11.2     INSURANCE TO BE OBTAINED BY TENANT.


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                                   17                   Tenant Initials: _______
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                  11.2.1 LIABILITY INSURANCE. During the Lease Term, Tenant
shall, at Tenant's expense, maintain a commercial general liability insurance
policy, or an equivalent, written on an occurrence form that includes personal
injury coverage, bodily injury, death, property damage, advertising injury
coverage and contractual liability coverage including Tenant's indemnity
obligations under this Lease, insuring against liability arising out of the
ownership, use, occupancy or maintenance of the Premises, and the business
operated by Tenant and any subtenants or licensees of Tenant in the Premises.
The initial amount of such insurance shall be Three Million Dollars
($3,000,000.00) each occurrence/Five Million Dollars ($5,000,000.00) general
aggregate on a per location basis and Three Million Dollars ($3,000,000.00) for
personal injury and advertising injury coverage. If alcohol will be served from
or in the Premises, such coverage shall contain endorsements deleting any liquor
liability exclusion and adding a liquor liability endorsement.

                  11.2.2 INSURANCE OF PERSONAL PROPERTY. Tenant shall at all
times during the Lease Term, and at its own expense, maintain a policy or
policies of standard fire, extended coverage and special extended coverage
insurance ("All Risks") with extended coverage in the name of the Tenant, and
naming Landlord as an additional insured, in an amount adequate to cover the
cost of replacement of all trade fixtures, alterations, decorations, inventory
additions or improvements, and all plate and tempered glass within the Premises,
made to the Premises by Tenant or by Landlord on Tenant's behalf in the event of
fire or extended coverage loss in an amount equal to the full replacement value.
Notwithstanding such insurance coverage by Tenant for plate glass, Landlord may
replace, at the expense of Tenant, any and all plate and other glass, frames or
glazing damaged or broken from any cause whatsoever in and about the Premises.

                  11.2.3 ADDITIONAL INSURANCE OBLIGATIONS. Landlord may
reasonably require Tenant to increase the amounts of coverage and/or to maintain
additional coverage based on insurance coverages and amounts maintained by
lessees of similar space in San Diego County.

         11.3 WAIVER OF SUBROGATION. Landlord and Tenant each hereby waive any
and all rights of recovery against the other or against the officers, employees,
agents and representatives of the other, on account of loss or damage occasioned
to such waiving party or its property or the property of others under its
control, to the extent that such loss or damage is insured against under any
fire and extended coverage insurance policy which either may have in force at
the time of such loss or damage or under the insurance policies required to be
maintained under this Article. Landlord and Tenant shall, if required, for each
of the policies of insurance required under this Lease, give notice to the
insurance carrier or carriers that the foregoing mutual waiver of subrogation is
contained in this Lease.

         11.4 FORM OF POLICIES. The minimum limits of policies of insurance
required of Tenant under this Lease shall in no event limit the liability of
Tenant under this Lease. Such insurance shall: (i)be an occurrence policy (or
policies); (ii)name Landlord, the Project or Building manager or managers, and
any other party having an interest in the Project as an additional insured;
(iii)be issued by an insurance company having a General Policyholders Rating of
B+ or better and a financial size of "VI" or better, as set forth in the most
current issue of Best's Rating Guide, or which is otherwise acceptable to
Landlord and licensed to do business in California; (iv)be primary insurance as
to all claims thereunder and provide that any insurance carried by Landlord is
excess and noncontributing with any insurance required of Tenant; (v)provide
that said insurance shall not be canceled or coverage changed unless thirty (30)
days prior written notice shall have been given to Landlord and any mortgagee of
Landlord's; and (vi)with respect to the liability insurance described in Section
11.2.1, contain a cross-liability endorsement or severability of interest clause
acceptable to Landlord. Any insurance policies required hereunder may be part of
a blanket policy with a "per project, per location" endorsement so long as such
blanket policy contains all provisions required hereby and does not reduce the
coverage, impair the rights of either party or negate the requirements of this
Lease. Tenant shall deliver said policy or policies or certificates thereof (at
Tenant's election), together with any endorsements reflecting the changes to the
policy required to comply with the requirements of this Lease, to Landlord on or
before the Commencement Date and at least ten (10) days before the expiration
date of such policies. In the event Tenant shall fail to procure such insurance,
or to deliver such policies or certificates (at Tenant's election) and
appropriate endorsements, Landlord may, at its option, procure such policies for
the account of Tenant, and the cost thereof plus a ten percent (10%) handling
charge shall be paid by Tenant to Landlord as Additional Rent within five (5)
days after delivery to Tenant of bills therefor.

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                                   18                   Tenant Initials: _______

<PAGE>   28

         11.5     INDEMNIFICATION.

                  11.5.1 INDEMNIFICATION OF LANDLORD. To the fullest extent
permitted by law, Tenant shall indemnify, protect, defend (with legal counsel
acceptable to Landlord) and save Landlord and Landlord's Indemnitees harmless
from and against any and all claims, actions, damages, liabilities and expenses,
including attorneys' fees, in connection with loss of life, personal injury,
bodily injury and/or damage to property arising from or out of any occurrence
in, upon or about the Premises, or the occupancy or use by Tenant of the
Premises and/or Project or any part thereof, or occasioned wholly or in part by
any act or omission of Tenant, its agents, contractors, employees, servants,
tenants or concessionaires, except to the extent caused by Landlord's gross
negligence or willful misconduct. Tenant shall further indemnify, defend,
protect and hold Landlord and Landlord's Indemnitees harmless from and against
any and all claims arising from any breach or default in performance of any
obligation on Tenant's part to be performed under the terms of this Lease, or
arising from any act, neglect, fault or omission of Tenant or its agents,
contractors, employees, servants, tenants or concessionaires, and from and
against all costs, attorneys' fees, expenses and liabilities incurred in
connection with such claim or any action or proceeding brought thereon. In case
any action or proceeding shall be brought against Landlord by reason of any such
claim, Tenant, upon notice from Landlord, shall defend the same at Tenant's
expense by counsel approved in writing by Landlord. Tenant, as a material part
of the consideration to Landlord, hereby assumes all risk of damage to property
or injury to persons in, upon or about the Premises from any cause whatsoever
except Landlord's gross negligence or intentional misconduct. Tenant hereby
waives all its claims in respect thereof against Landlord.

                  11.5.2 LANDLORD'S NONLIABILITY. Landlord shall not be liable
for injury or damage which may be sustained by a person, goods, wares,
merchandise, or other property of Tenant, or Tenant's employees, invitees,
customers, or of any other person in or about the Premises caused by or
resulting from any peril which may affect the Premises, including, without
limitation, fire, steam, electricity, gas, water, or rain which may leak or flow
from or into any part of the Premises, or from the breakage, leakage,
obstruction, or other defects of the pipes, sprinklers, wires, appliances,
plumbing, air conditioning, or lighting fixtures of the Premises, whether such
damage or injury results from conditions arising upon the Premises or upon other
portions of the Project or from other sources. Landlord shall not be liable for
any damages arising from any act or neglect of: (a) any other tenant or occupant
of the Project; or (b) any officer, employee, agent, representative, customer,
business visitor, or invitee of any such tenant. Notwithstanding the foregoing,
nothing contained in this Lease shall operate to relieve Landlord of the
consequences of its own gross negligence or willful misconduct or the gross
negligence or willful misconduct of its agents or employees.

                  11.5.3 INDEMNIFICATION OF TENANT. To the fullest extent
permitted by law, Landlord shall indemnify, protect, defend (with legal counsel
acceptable to Tenant) and save Tenant and Tenant's Indemnitees harmless from and
against any and all claims, actions, damages, liabilities and expenses,
including attorneys' fees, in connection with loss of life, personal injury,
bodily injury and/or damage to property arising from or out of any occurrence
in, upon or about the Premises and due to the gross negligence or willful
misconduct of Landlord. Except as otherwise set forth in this Lease, and subject
to Section 11.5.2 above, Landlord shall further indemnify, defend, protect and
hold Tenant and Tenant's Indemnitees harmless from and against any and all
losses, expenses and damages arising from any breach or default in performance
of any obligation on Landlord's part to be performed under the terms of this
Lease.

                     ARTICLE 12 - ASSIGNMENT AND SUBLETTING

         12.1     LANDLORD'S CONSENT REQUIRED.

                  12.1.1 TRANSFER. Tenant shall not either voluntarily or by
operation of law, assign, mortgage, pledge, hypothecate or encumber this Lease
or the leasehold interest created hereby or any interest herein, or sublet the
Premises or any portion thereof, or license the use of all or any portion of the
Premises or permit any other person to occupy or use the Premises or any portion
thereof (collectively referred to herein as a "Transfer"), without the prior
written consent of Landlord, which consent is subject to the following
conditions: (i)the proposed transferee's use of

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                                   19                   Tenant Initials: _______


<PAGE>   29

the Premises must be consistent with Article 6 hereof; (ii)the transferee is of
a character and engaged in a business which is in keeping with the Landlord's
standards for the Project; (iii)the proposed Transfer must not breach any
financing agreement or any other agreement relating to the Project; (iv)the net
worth of the proposed transferee must be sufficient to discharge the obligation
under this Lease (in Landlord's reasonable judgment); and (v)subject to Landlord
not having available space in the Project for such proposed transferee, the
proposed transferee must not be an existing tenant in the Project.

                  12.1.2 PROCEDURE. Prior to a Transfer, Tenant shall request
Landlord's consent in writing, and shall include with such request a copy of all
proposed contracts, agreements, subleases, or other documents describing the
Transfer between Tenant and the proposed transferee. Landlord shall respond to
Tenant's request for consent to a proposed Transfer within thirty (30) days
after receipt of all information described above and reasonably necessary to
allow Landlord to evaluate all the conditions set forth in Section 12.1.1 above.
If Tenant hereunder is a corporation or is an unincorporated association or
partnership, then the transfer, assignment, or hypothecation of any stock or
interest in such corporation, association or partnership in the aggregate in
excess of twenty-five percent (25%) shall be deemed a Transfer under the meaning
of this Article 12 (other than normal bulk transactions of publicly held stock).

                  12.1.3 AFFILIATES. Notwithstanding the foregoing, Landlord's
prior written consent shall not be required for a Transfer to a wholly owned
subsidiary or a parent of Tenant ("Affiliate"). Promptly upon a transfer to an
Affiliate, Tenant shall deliver written notice to Landlord thereof.

         12.2 RECAPTURE RIGHT. In lieu of giving or withholding consent pursuant
to Section 12.1, Landlord may, at its option, terminate this Lease (or in the
case of a proposed subletting or assignment of a portion of the Premises, elect
to terminate this Lease as respects that portion) upon thirty (30) days' prior
notice. Thereafter Landlord may enter into a lease agreement with such proposed
transferee and shall be entitled to all of the Profit related thereto. In
consideration for Landlord's right and election to terminate this Lease as set
forth above, Landlord will release Tenant from liability under this Lease for
Base Monthly Rent and Additional Rent with respect to the Premises (or the
portion of the Premises subject to the proposed Transfer) accruing after
termination of this Lease resulting from Landlord's exercise of such right.
Landlord and Tenant agree and acknowledge that Landlord's right to recapture as
set forth above is intended to permit Landlord to maintain control over the
leasing of space in the Project to protect its interest in the Project and the
interest of any lenders and to prevent such interest from being impaired. Tenant
understands the nature of this right and has approved the recapture provisions
in consideration for Landlord's agreement to release Tenant from liability for
future Rent due with respect to the recaptured portion of the Premises pursuant
to the provisions of this Section.

         12.3 TRANSFER WITHOUT CONSENT. Any Transfer without Landlord's prior
written consent shall, at the option of the Landlord, constitute a non-curable
breach of this Lease.

         12.4 NO RELEASE OF TENANT. No Transfer shall release Tenant or any
guarantor or change Tenant's primary liability to pay the Rent and to perform
all other obligations of Tenant under this Lease. Landlord's acceptance of Rent
from any other person is not a waiver of any provision of this Article 12.
Consent to one Transfer is not a consent to any subsequent Transfer. If Tenant's
transferee defaults under this Lease, Landlord may proceed directly against
Tenant without pursuing remedies against the transferee and without releasing
such transferee from its obligations under this Lease. Landlord may consent to
subsequent assignments or modifications of this Lease by Tenant's transferee,
without notifying Tenant or obtaining its consent. Such action shall not relieve
Tenant's liability under this Lease.

         12.5 EFFECT OF A TRANSFER. Whether or not Landlord's consent is
required, the transferee shall agree to comply with and be bound by all of the
terms, covenants, conditions, provisions and agreements of this Lease to the
extent of the space transferred, assigned or sublet; and Tenant shall deliver to
Landlord promptly after execution an executed copy of each such Transfer
document between Tenant and the transferee. In addition, any sublease shall
provide that it shall be subject and subordinate to this Lease and to all
mortgages; that Landlord may enforce the provisions of the sublease, including
collection of rents; and that in the event of termination of this Lease for any
reason, including without limitation a voluntary surrender by Tenant, or in the
event of any reentry or repossession of

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<PAGE>   30

the Premises by Landlord, Landlord may, at its option, either (i)terminate the
sublease, or (ii)take over all of the right, title and interest of Tenant, as
sublessor, under such sublease, in which case such sublessee shall attorn to
Landlord but in such event Landlord shall not (a)be liable for any previous act
or omission of Tenant under such sublease, (b)be subject to any defense or
offset previously accrued in favor of the sublessee against Tenant, or (c)be
bound by any previous modification of any sublease made without Landlord's
written consent, or by any previous prepayment by sublessee of more than one
month's rent.

         12.6 EVENT OF BANKRUPTCY. If this Lease is assigned to any person or
entity pursuant to the provisions of the United States Bankruptcy Code, 11
U.S.C. Section 101 et seq. (the "Bankruptcy Code"), any and all monies or other
consideration payable or otherwise to be delivered in connection with such
assignment shall be paid or delivered to Landlord, shall be and remain the
exclusive property of Landlord, and shall not constitute the property of Tenant
or of the estate of Tenant within the meaning of the Bankruptcy Code. Any and
all monies or other considerations constituting Landlord's property under this
Section not paid or delivered to Landlord shall be held in trust for the benefit
of Landlord and shall be promptly paid or delivered to Landlord. Any person or
entity to which this Lease is assigned pursuant to the provisions of the
Bankruptcy Code shall be deemed without further act or deed to have assumed all
of the obligations arising under this Lease on and after the date of such
assignment.

         12.7 NO MERGER. No merger shall result from Tenant's sublease of
the Premises under this Article 12, Tenant's surrender of this Lease or the
termination of this Lease in any other manner.

         12.8 ASSIGNMENT FEES AND PROCEDURES. In the event Landlord shall be
requested to consent to a Transfer, Tenant shall pay Landlord a reasonable fee
to reimburse Landlord for costs and expenses, including attorneys' fees,
incurred in connection with reviewing Tenant's request for consent.

                       ARTICLE 13 - DAMAGE OR DESTRUCTION

         13.1 REPAIR OF DAMAGE BY LANDLORD. Tenant agrees to promptly notify
Landlord in writing of any damage to the Premises resulting from fire,
earthquake or any other casualty (such events referred to collectively as
"Casualty"). If the Premises, or any common areas of the Building providing
access to the Premises (such that Tenant does not have reasonable access to the
Premises) shall be damaged by a Casualty, Landlord shall, within sixty (60) days
after the date of the Casualty, provide written notice to Tenant indicating the
anticipated time period for repairing the Casualty (the "Repair Period Notice").
In the event the Repair Period Notice indicates that the time period for
repairing the Casualty is estimated to exceed two hundred seventy (270) days
from the date of the Repair Period Notice, Landlord (pursuant to the provisions
of Section 13.3 below) or Tenant may elect to terminate this Lease ("Tenant's
Termination Election"). Such election must be made by Tenant within thirty (30)
days after the receipt of the Repair Period Notice or will be deemed waived by
Tenant. If Tenant elects to terminate the Lease, the termination shall be
effective thirty (30) days after Landlord's receipt of Tenant's Termination
Election. If the Repair Period Notice indicates that the time period for
repairing the Casualty is estimated to not exceed two hundred seventy (270) days
from the date of the Repair Period Notice, or if Tenant does not exercise
Tenant's Termination Election as provided above, then subject to the other
provisions of this Article, Landlord will repair the damage pursuant to the
provisions hereof. If Landlord is obligated to or elects to repair the Casualty
as provided herein, Landlord agrees to promptly and diligently, subject to
reasonable delays for insurance adjustment and other matters beyond Landlord's
reasonable control, and subject to the other provisions of this Article, restore
the Premises and the Tenant Improvements originally constructed by Landlord to
substantially the same condition as existed prior to the Casualty, except for
modifications required by building codes and other laws, and any other
modifications to the common areas deemed desirable by Landlord provided that
access to the Premises shall not thereby be materially impaired. If Tenant
requests that Landlord make any modifications to the Tenant Improvements in
connection with the rebuilding, Landlord may condition its consent to such
modifications on (i) Tenant's payment to Landlord prior to commencement of
construction of any sums necessary to complete the Tenant Improvements in excess
of the amount of insurance proceeds received by Landlord and (ii)confirmation by
Landlord's architect that the modifications will not increase the scope of work
or time period necessary to complete the Tenant Improvements.

         13.2 RENT ABATEMENT DUE TO CASUALTY. Landlord and Tenant agree and
acknowledge that Tenant shall

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<PAGE>   31

be provided with full abatement of Rent during the time period commencing on the
last to occur of (i) the date of the Casualty or (ii) the date Tenant ceases to
enjoy the substantial benefit of the Premises, and continuing until Substantial
Completion of Landlord's restoration obligations as provided herein ("Abatement
Period"), provided that if Tenant is only able to occupy a portion of the
Premises and receive the substantial benefit of such portion for Tenant's uses
of the Premises, Rent shall be abated during the Abatement Period for the
portion of the Premises not occupied by Tenant. Landlord and Tenant acknowledge
and agree that the Rent abatement as provided in this Section is Tenant's sole
remedy due to the occurrence of the Casualty and that Landlord shall not be
liable to Tenant or any other person for any direct, indirect or consequential
damage (including, but not limited to, lost profits of Tenant or loss of or
interference with Tenant's business, or otherwise), whether or not caused by the
negligence of Landlord or Landlord's employees, contractors, licensees, or
invitees, due to or arising out of or as a result of the Casualty (including but
not limited to the termination of the Lease in connection therewith). Tenant
acknowledges and agrees that Tenant shall maintain adequate business
interruption insurance to provide coverage as to such matters.

         13.3 LANDLORD'S OPTION TO REPAIR. Notwithstanding the terms of
Section13.1 of this Lease, Landlord may elect not to rebuild and/or restore the
Premises and/or Building and to instead terminate this Lease by notifying Tenant
in writing of such termination within sixty (60) days after the date of the
Casualty in the event the Building shall be damaged by Casualty (whether or not
the Premises are affected) and one or more of the following conditions exists:
(i)Landlord determines that the time period for repair will exceed two hundred
seventy (270) days as provided in Section 13.1 above; (ii)the damage is not
fully covered, except for deductible amounts, by insurance required to be
carried by Landlord under the terms of this Lease; (iii)the holder of the
mortgage on the Building or ground lessor with respect to the Project requires
that the insurance proceeds or a portion thereof be used to retire the mortgage
debt, or terminates the ground Lease, as the case may be; or (iv)Landlord elects
not to rebuild the Building for any reason, provided that in connection with
such election Landlord also terminates all other leases in the Building.

         13.4 DAMAGE NEAR END OF TERM. In the event that the Premises or the
Building is destroyed or damaged by a Casualty during the last two (2) years of
the Lease Term, notwithstanding anything else contained in this Article,
Landlord shall have the option to terminate this Lease by giving written notice
to Tenant of the exercise of such option within thirty (30) days after such
damage or destruction, in which event this Lease shall cease and terminate as of
the date of the notice. In such event or in the event of a termination pursuant
to the other provisions of this Article, Tenant shall pay Rent, properly
apportioned up to the date of the Casualty, and both parties shall thereafter be
freed and discharged of all future obligations hereunder, except for any
provisions of this Lease which by their terms survive the expiration or earlier
termination of the Lease Term.

         13.5 WAIVER OF STATUTORY PROVISIONS. The provisions of this Lease,
including this Article13, constitute an express agreement between Landlord and
Tenant with respect to the occurrence of any Casualty to the Premises and/or
Building or any other portion of the Project and Tenant therefore fully waives
the provisions of any statute or regulation, including, without limitation,
Sections 1932(2) and 1933(4) of the California Civil Code, with respect to any
rights or obligations concerning a Casualty.

                            ARTICLE 14 - CONDEMNATION

         14.1 TOTAL CONDEMNATION. If the whole of the Premises shall be acquired
or condemned by eminent domain for any public or quasi-public use or purpose,
then the Lease Term shall cease and terminate as of the date of title vesting in
such proceeding and all rentals shall be paid up to that date.

         14.2 PARTIAL CONDEMNATION. If any part of the Premises shall be
acquired or condemned by eminent domain for any public or quasi-public use or
purpose, and if such partial taking or condemnation renders the Premises
reasonably unsuitable for the business of the Tenant, then Tenant shall have the
right to terminate the Lease Term as of the date of title vesting in such
proceeding by delivering written notice thereof to Landlord within thirty (30)
days after Tenant becomes aware of the proposed condemnation. In the event of a
partial taking or condemnation which is not extensive enough to render the
Premises unsuitable for the business of the Tenant then this Lease shall
continue in full force and effect.


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<PAGE>   32

         14.3 CONDEMNATION OF PARKING AREA. If the whole or any part of the
parking area in the Project shall be acquired or condemned by eminent domain for
any public or quasi-public use or purpose and if, as the result of such partial
taking, the ratio of the number of parking stalls does not conform to the
parking requirements of this Lease ("Parking Restrictions"), in effect at the
time that title to such parking area is acquired through such condemnation
process, then the Lease Term shall cease and terminate from the date of title
vesting in such proceeding unless Landlord provides substantially equal parking
facilities in the vicinity of the Project within sixty (60) days after the date
of acquisition and such alternative parking satisfies the requirements of the
Parking Restrictions.

         14.4 DISTRIBUTION OF CONDEMNATION AWARD. Any condemnation award or
payment shall be distributed in the following order: (a)first, to any ground
lessor, mortgagee or beneficiary under a deed of trust encumbering the Premises,
the amount of its interest in the Premises; (b)second, to Tenant, only the
amount, if any, of any award specifically designated for loss of or damage to
Tenant's movable trade fixtures or removable personal property, and the Tenant
hereby assigns any other rights which the Tenant may have now or in the future
to any other award to the Landlord; and (c)third, to Landlord, the remainder of
such award, whether as compensation for reduction in the value of the leasehold,
the taking of the fee, or otherwise. In no event shall Tenant have any claim
against Landlord for the value of any unexpired term of this Lease. If this
Lease is not terminated, Landlord shall repair any damage to the Premises caused
by the condemnation, except that Landlord shall not be obligated to repair any
damage for which Tenant has been reimbursed by the condemning authority.

         14.5 WAIVER. Tenant hereby waives any statutory rights of termination
which may arise by reason of any taking of the Premises under the power of
eminent domain, including, without limitation, the provisions of Section
1265.130 of the California Code of Civil Procedure.

                         ARTICLE 15 - DEFAULTS; REMEDIES

         15.1 COVENANTS AND CONDITIONS. Tenant's performance of each of
Tenant's obligations under this Lease is a condition as well as a covenant.
Tenant's right to continue in possession of the Premises is conditioned upon
such performance. Time is of the essence in the performance of all covenants and
conditions.

         15.2 DEFAULTS BY TENANT. Tenant shall be in default under this Lease if
Tenant breaches its obligations hereunder and fails to cure such breach within
the period set forth herein, except that there shall be no cure period for
breaches of Sections 15.2.3 and 15.2.4, and the cure period for breaches of
Section 15.2.2 shall be the minimum mandated by California statute. Tenant shall
be in breach of its obligations under this Lease:

                  15.2.1 If Tenant abandons or vacates the Premises;

                  15.2.2 If Tenant fails to pay Base Monthly Rent, Additional
Rent or any Rent required to be paid by Tenant, as and when due;

                  15.2.3 If Tenant fails or refuses to occupy and operate the
Premises in accordance with Article 6;

                  15.2.4 If (i) Tenant's use of the Premises involves the
generation or storage, use, treatment or disposal of Hazardous Material in a
manner or for a purpose prohibited by any Hazardous Materials Law; (ii) Tenant
has been required by any lender or governmental authority to take remedial
action in connection with Hazardous Material contaminating the Premises if the
contamination resulted from Tenant's action or use of the Premises; or (iii)
Tenant is subject to an enforcement order issued by any governmental authority
in connection with the use, disposal or storage of a Hazardous Material on the
Premises.

                  15.2.5 If Tenant fails to perform any of Tenant's nonmonetary
obligations under this Lease (other than Tenant's obligations under Sections
15.2.3, 15.2.4 and 15.2.6 for which there will be no additional cure periods)
for a period of twenty (20) days after written notice from Landlord; provided
that if such cure is not reasonably susceptible of being cured within such
twenty (20) day period, Tenant shall not be in default if Tenant commences such
performance within the twenty (20) day period and uses its best efforts and due
diligence to promptly cure the 

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default. However, Landlord shall not be required to give such notice if Tenant's
failure to perform constitutes a non-curable breach of this Lease. The notice
required by this Section is intended to satisfy any and all notice requirements
imposed by law on Landlord prior to the commencement of an unlawful detainer
action and is not in addition to any such requirement;

                  15.2.6 If (i)Tenant makes a general assignment or general
arrangement for the benefit of creditors; (ii)Tenant files a petition for
adjudication of bankruptcy or for reorganization or rearrangement or any similar
proceeding; (iii)a petition for adjudication of bankruptcy or for reorganization
or rearrangement is filed against Tenant and is not dismissed within forty-five
(45) days; (iv)a trustee or receiver is appointed to take possession of
substantially all of Tenant's assets located at the Premises or of Tenant's
interest in this Lease and possession is not restored to Tenant within
forty-five (45) days; or (v)substantially all of Tenant's assets located at the
Premises or of Tenant's interest in this Lease is subjected to attachment,
execution or other judicial seizure which is not discharged within forty-five
(45) days. If a court of competent jurisdiction determines that any of the acts
described in this subsection is not a default under this Lease, and a trustee is
appointed to take possession (or if Tenant remains a debtor in possession) and
such trustee or Tenant transfers Tenant's interest hereunder, then Landlord
shall receive, as Additional Rent, the difference between the Rent (or any other
consideration) paid in connection with such assignment or sublease and the Rent
payable by Tenant hereunder.

         15.3 REMEDIES. On the occurrence of any default by Tenant, Landlord
may, at any time thereafter, with or without notice or demand and without
limiting Landlord in the exercise of any right or remedy which Landlord may
have:

                  15.3.1 Terminate Tenant's right to possession of the Premises
by any lawful means, in which case this Lease shall terminate and Tenant shall
immediately surrender possession of the Premises to Landlord. In such event
Landlord shall have the immediate right to re-enter the Premises and remove all
persons and property and such property may be removed and stored in a public
warehouse or elsewhere at the cost of, and for the account of Tenant, all
without service of notice or resort to legal process and without being deemed
guilty of trespass, or becoming liable for any loss or damage which may be
occasioned thereby; and Landlord shall be entitled to recover from Tenant all
damages incurred by Landlord by reason of Tenant's default, including (i)the
worth at the time of the award of all Base Monthly Rent, Additional Rent and
other charges which were earned or were payable at the time of the termination;
(ii)the worth at the time of the award of the amount by which the unpaid Base
Monthly Rent, Additional Rent and other charges which would have been earned or
were payable after termination until the time of the award exceeds the amount of
such rental loss that Tenant proves could have been reasonably avoided; (iii)the
worth at the time of the award of the amount by which the unpaid Base Monthly
Rent, Additional Rent and other charges which would have been payable for the
balance of the term after the time of award exceeds the amount of such rental
loss that Tenant proves could have been reasonably avoided; and (iv)any other
amount necessary to compensate Landlord for all the detriment proximately caused
by Tenant's failure to perform its obligations under this Lease or which in the
ordinary course of things would be likely to result therefrom, including, but
not limited to, any costs or expenses incurred by Landlord in maintaining or
preserving the Premises after such default, the cost of recovering possession of
the Premises, expenses of reletting, including, without limitation, necessary
renovation or alteration of the Premises, Landlord's reasonable attorneys' fees,
and any real estate commissions or other such fees paid or payable. Any such
sums which are based on percentages of income, increased costs or other data
shall be reasonable estimates or projections computed by Landlord on the basis
of the amounts thereof accruing during the twenty-four (24) month period
immediately prior to the default, except that if it becomes necessary to compute
such sums before a twenty-four (24) month period has expired, then the
computation shall be made on the basis of the amounts accruing during such
shorter period. As used in subsections (i) and (ii) above, the "worth at the 
time of the award" is computed by allowing interest on unpaid amounts at the
rate of fifteen percent (15%) per annum, but if such rate exceeds the maximum
interest rate permitted by law, such rate shall be reduced to the highest rate
allowed by law under the circumstances. As used in subsection (iii) above, the
"worth at the time of the award" is computed by discounting such amount at the
discount rate of the Federal Reserve Bank of San Francisco at the time of the
award, plus one percent (1%). If Tenant shall have abandoned the Premises,
Landlord shall have the option of (a)retaking possession of the Premises and
recovering from Tenant the amount specified in this Section 15.3.1, or
(b)proceeding under Section 15.3.2 below;

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                  15.3.2 Maintain Tenant's right to possession, in which case
this Lease shall continue in effect whether or not Tenant shall have abandoned
the Premises. This remedy is intended to be that remedy described in California
Code of Civil Procedure Section 1951.4. In such event, Landlord shall be
entitled to enforce all of Landlord's rights and remedies under this Lease,
including the right to recover the Rent as it becomes due hereunder; and/or

                  15.3.3 Whether or not Landlord elects to terminate this Lease
on account of any default by Tenant, Landlord shall have all rights and remedies
at law or in equity including, but not limited to, the right to re-enter the
Premises, and Landlord shall have the right to terminate any and all subleases,
licenses, concessions or other arrangements for possession entered into by
Tenant and affecting the Premises or may, in Landlord's sole discretion, succeed
to Tenant's interest in such subleases, licenses, concessions or arrangements.
In the event of Landlord's election to succeed to Tenant's interest in any such
subleases, licenses, concessions or arrangements, Tenant shall, as of the date
of notice by Landlord of such election, have no further right to or interest in
the Rent or other consideration receivable thereunder.

         15.4 THE RIGHT TO RELET THE PREMISES. Should Landlord elect to
re-enter, as herein provided, or should it take possession pursuant to legal
proceedings or pursuant to any notice provided for by law, it may either
terminate this Lease or it may from time to time without terminating this Lease,
make such alterations and repairs as may be necessary in order to relet the
Premises, and relet said Premises or any part thereof for such term or terms
(which may be for a term extending beyond the Lease Term) and at such rental or
rentals and upon such other terms and conditions as Landlord in its sole
discretion may deem advisable; upon each such reletting all rentals received by
the Landlord from such reletting shall be applied, first, to the repayment of
any indebtedness other than Rent due hereunder from Tenant to Landlord; second,
to the payment of any costs and expenses of such reletting, including brokerage
fees and attorneys' fees and of costs of such alterations and repairs; third, to
the payment of Rent due and unpaid hereunder, and the residue, if any, shall be
held by Landlord and applied in payment of future Rent as the same may become
due and payable hereunder. If such rentals received from such reletting during
any month are less than that to be paid during that month by Tenant hereunder,
Tenant shall pay any such deficiency to Landlord. Such deficiency shall be
calculated and paid monthly. No such re-entry or taking possession of said
Premises by Landlord shall be construed as an election on its part to terminate
this Lease unless a written notice of such intention be given to Tenant or
unless the termination thereof be decreed by a court of competent jurisdiction.

         15.5 WAIVER OF RIGHTS OF REDEMPTION. Tenant hereby expressly waives any
and all rights of redemption granted by or under any present or future laws in
the event of Tenant being evicted or dispossessed for any cause, or in the event
of Landlord obtaining possession of the Premises, by reason of the violation by
Tenant of any of the covenants or conditions of this Lease, or otherwise.

         15.6 CUMULATIVE REMEDIES. Landlord's exercise of any right or remedy
stated or set forth anywhere in this Lease shall not prevent Landlord from
exercising any other right or remedy which may be provided by law, in equity or
this Lease, whether or not stated in this Lease. The termination of this Lease
under this Article 15 shall not release Tenant from obligations arising as a
result of any acts or omissions occurring prior to such expiration or
termination, including, without limitation, any indemnity obligations of Tenant
and any obligations of Tenant under Article 7 of this Lease and all such
obligations shall survive such termination.

         15.7 ADDITIONAL REMEDIES UPON DEFAULT. In addition to any rights or
remedies hereinbefore or hereinafter conferred upon Landlord under the terms of
this Lease, the following remedies and provisions shall specifically apply in
the event Tenant engages in any one or more of the acts contemplated by the
provisions of Section15.2.6 of this Lease:

                  15.7.1 ASSUMPTION OR REJECTION OF LEASE. In all events, any
receiver or trustee in bankruptcy shall either expressly assume or reject this
Lease within sixty (60) days following the entry of an "Order for Relief" or
within such earlier time as may be provided by applicable law. In the event of
an assumption of this Lease by a debtor or by a trustee, such debtor or trustee
shall within fifteen (15) days after such assumption (i) cure any default or

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provide adequate assurance that defaults will be promptly cured; (ii) compensate
Landlord for actual monetary loss or provide adequate assurance that
compensation will be made for actual monetary loss, including, but not limited
to, all attorneys' fees and costs incurred by Landlord resulting from any such
proceedings; and (iii) provide adequate assurance of future performance. Where a
default exists under this Lease, the trustee or debtor assuming this Lease may
not require Landlord to provide services or supplies incidental to this Lease
before its assumption by such trustee or debtor, unless Landlord is compensated
under the terms of this Lease for such services and supplies provided before the
assumption of such Lease;
                        
                  15.7.2 ASSIGNMENT. The debtor or trustee may only assign this
Lease if (i) it is assumed and assignee agrees to be bound by this Lease, (ii)
adequate assurance of future performance by the assignee is provided, whether or
not there has been a default under this Lease, and (iii) the debtor or trustee
has received Landlord's prior written consent pursuant to the provisions of
Section 12.1 of this Lease. Any consideration paid by any assignee in excess of
the rental reserved in this Lease shall be the sole property of, and paid to,
Landlord. Landlord shall be entitled to the fair market value for the Premises
and the services provided by Landlord (but in no event less than the Rent
reserved in this Lease) subsequent to the commencement of a bankruptcy event;

                  15.7.3 OTHER MATTERS. Any Security Deposit and the Additional
Security given by Tenant to Landlord or Landlord's construction lender to secure
the future performance by Tenant of all or any of the terms and conditions of
this Lease shall be automatically transferred to Landlord upon the entry of an
"Order of Relief." The parties agree that Landlord is entitled to adequate
assurance of future performance of the terms and provisions of this Lease in the
event of an assignment under the provisions of the Bankruptcy Code. For purposes
of any such assumption or assignment of this Lease, the parties agree that the
term "adequate assurance" shall include, without limitation, at least the
following: (a)any proposed assignee must have, as demonstrated to Landlord's
satisfaction, a net worth (as defined in accordance with generally accepted
accounting principles consistently applied) in an amount sufficient to assure
that the proposed assignee will have the resources to meet the financial
responsibilities under this Lease, including the payment of all Rent. The
financial condition and resources of Tenant are material inducements to Landlord
entering into this Lease; (b)any proposed assignee must not be engaged in any
business or activity which it will conduct on the Premises and which will
subject the Premises to contamination by any Hazardous Materials; (c)any
proposed assignee must agree in writing to be bound by all the terms and
provisions of this Lease.

         15.8 DEFAULT BY LANDLORD. Landlord shall not be in default unless
Landlord fails to perform obligations required of Landlord within a reasonable
time, but in no event later than thirty (30) days after written notice by Tenant
to Landlord and to the holder of any first mortgage or deed of trust covering
the Premises whose name and address shall have theretofore been furnished to
Tenant in writing, specifying wherein Landlord has failed to perform such
obligation; provided, however, that if the nature of Landlord's obligation is
such that more than thirty (30) days are required for performance, then Landlord
shall not be in default if Landlord commences performance within such thirty
(30) day period and thereafter diligently prosecutes the same to completion.

         15.9 LANDLORD'S CURE. All covenants and agreements to be kept or
performed by Tenant under this Lease shall be performed by Tenant at Tenant's
sole cost and expense and without any reduction or abatement of Base Monthly
Rent, Additional Rent or any other Rent payable under the Lease except for any
abatement specifically permitted under Article 13 of this Lease. If Tenant shall
default in the performance of its obligations under this Lease, Landlord may,
but shall not be obligated to, make any such payment or perform any such act on
Tenant's part without waiving its right based upon any default of Tenant and
without releasing Tenant from any obligations hereunder and Tenant shall, within
fifteen (15) days after delivery by Landlord to Tenant of statements therefor
reimburse Landlord for all such expenditures, losses, costs, liabilities,
damages and expenses. All sums so paid by Landlord and all necessary incidental
costs, and interest thereon at the Lease Interest Rate accruing from the date
paid or incurred by Landlord until reimbursed to Landlord by Tenant, shall be
payable to Landlord by Tenant as Rent on demand and Tenant covenants to pay all
such sums. Tenant's obligations under this Sections hall survive the expiration
or sooner termination of the Lease Term.

                      ARTICLE 16 - PROTECTION OF CREDITORS

         16.1     SUBORDINATION. Landlord shall have the right to require Tenant
to subordinate this Lease to any

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ground lease, deed of trust, mortgage or the Declarations encumbering the
Premises, any advances made on the security thereof and any renewals,
modifications, consolidations, replacements or extensions thereof, whenever made
or recorded. Landlord may, by written notice to Tenant, subordinate this Lease
to any new Declarations. If any beneficiary under a deed of trust or mortgagee
under a mortgage elects to have this Lease prior to the lien of its deed of
trust or mortgage and gives written notice thereof to Tenant, this Lease shall
be deemed prior to such deed of trust or mortgage whether this Lease is dated
prior or subsequent to the date of said deed of trust or mortgage or the date of
recording thereof. As a condition to any such subordination, Landlord's lender
shall provide to Tenant a commercially reasonable nondisturbance agreement
(which may be part of a subordination and attornment agreement) recognizing
Tenant's right to possession of the Premises so long as Tenant is not in default
under this Lease beyond any applicable cure period.

         16.2 ATTORNMENT. If Landlord's interest in the Premises is acquired by
any ground lessor, beneficiary under a deed of trust, mortgagee, or purchaser at
a foreclosure sale, or by any other person or entity, as a result of any other
transfer by Landlord, Tenant shall attorn to the transferee of or successor to
Landlord's interest in the Premises and recognize such transferee or successor
as Landlord under this Lease. Tenant waives the protection of any statute or
rule of law which gives or purports to give Tenant any right to terminate this
Lease or surrender possession of the Premises upon the transfer of Landlord's
interest.

         16.3 SIGNING OF DOCUMENTS. Tenant shall sign and deliver any instrument
or documents necessary or appropriate to effectuate or evidence any such
attornment or subordination or agreement to do so. If Tenant fails to do so
within ten (10) days after written request,such failure shall constitute a
default under this Lease entitling Landlord to terminate this Lease.

         16.4 ESTOPPEL CERTIFICATES.

                  16.4.1 REQUEST. Upon either party's written request
("Requesting Party"), the other party ("Responding Party") shall execute,
acknowledge and deliver to the Requesting Party a written statement certifying:
(i)that none of the terms or provisions of this Lease have been changed (or if
they have been changed, stating how they have been changed); (ii)that this Lease
has not been canceled or terminated and is in full force and effect; (iii)the
last date of payment of the Base Monthly Rent, and other charges and the time
period covered by such payment; (iv)that the Requesting Party is not in default
under this Lease (or, if the Requesting Party is claimed to be in default,
stating why) and (v)such other statements as required by the Requesting Party,
or any lender or prospective lender, investor or purchaser. The Responding Party
shall deliver such statement to the Requesting Party within ten (10) days after
the Requesting Party's request. Any such statement by the Responding Party may
be given by the Requesting Party to any prospective purchaser or encumbrancer of
the Premises. Such purchaser or encumbrancer may rely conclusively upon such
statement as true and correct.

                  16.4.2 FAILURE TO RESPOND. If the Responding Party does not
deliver such statement to the Requesting Party within such ten (10) day period,
such failure shall constitute a default under this Lease. Further, the
Requesting Party and any prospective purchaser or encumbrancer, may conclusively
presume and rely upon the following facts: (i)that the terms and provisions of
this Lease have not been changed except as otherwise represented by the
Requesting Party; (ii)that this Lease has not been canceled or terminated except
as otherwise represented by the Requesting Party; (iii)that not more than one
month's Base Monthly Rent or other charges have been paid in advance; and
(iv)that Landlord is not in default under this Lease. In such event, the
Requesting Party shall be estopped from denying the truth of such facts.

         16.5 TENANT'S FINANCIAL CONDITION. Within ten (10) days after written
request from Landlord, Tenant shall deliver to Landlord such financial
statements as are reasonably required by Landlord and are available to the
public to verify the net worth of Tenant, or any assignee, subtenant, or
guarantor of Tenant. Tenant covenants that during the term of this Lease Tenant
shall maintain a minimum net worth of Ten Million Dollars ($10,000,000.00). In
addition, Tenant shall deliver to any lender or proposed purchaser of the
Premises or any portion of the Project designated by Landlord any financial
statements required by such lender or purchaser (which are available to the
public) to facilitate the sale, financing or refinancing of the Premises or any
portion of the Project. Tenant represents

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and warrants to Landlord that each such financial statement is a true and
accurate statement as of the date of such statement. All financial statements
shall be confidential and shall be used only for the purposes set forth herein.
Each such financial statement shall be executed by Tenant and shall be certified
by Tenant to be true and correct.

         16.6 MORTGAGEE PROTECTION CLAUSE. Tenant agrees to give any mortgagees
and/or trust deed holders, by registered mail, a copy of any notice of default
served upon the Landlord, provided that prior to such notice Tenant has been
notified in writing of the addresses of such mortgagees and/or trust deed
holders. Tenant further agrees that if Landlord shall have failed to cure such
default within the time provided for in this Lease, then the mortgagees and/or
trust deed holders shall have an additional thirty (30) days within which to
cure such default or if such default cannot be cured within that time, then such
additional time as may be necessary if within such thirty (30) days any
mortgagee and/or trust deed holder has commenced and is diligently pursuing the
remedies necessary to cure such default (including but not limited to
commencement of foreclosure proceedings if necessary to effect such cure), in
which event this Lease shall not be terminated while such remedies are being so
diligently pursued.

                        ARTICLE 17 - TERMINATION OF LEASE

         17.1 CONDITION UPON TERMINATION. Upon the termination of this Lease,
Tenant shall surrender the Premises to Landlord, broom clean and in the same
condition as received except for ordinary wear and tear which Tenant was not
otherwise obligated to remedy under any provision of this Lease. However, Tenant
shall not be obligated to repair any damage which Landlord is required to repair
under Article 14 of this Lease. No act done by Landlord or any agent or employee
of Landlord during the Lease Term shall be deemed to constitute an acceptance by
Landlord of a surrender of the Premises unless such intent is specifically
acknowledged in writing and signed by Landlord. The delivery of keys to the
Premises to Landlord or any agent or employee of Landlord shall not constitute a
surrender of the Premises or effect a termination of this Lease, whether or not
the keys are thereafter retained by Landlord and, notwithstanding such delivery,
Tenant shall be entitled to the return of such keys at any reasonable time upon
request until this Lease shall have been properly terminated. The voluntary or
other surrender of this Lease by Tenant, whether accepted by Landlord or not, or
a mutual termination hereof, shall not work a merger, and, at the option of
Landlord, shall operate as an assignment to Landlord of all subleases or
subtenancies affecting the Premises.

         17.2 NON-REMOVAL BY TENANT. All Alterations, including signs and sign
cases, made by Tenant, or made by the Landlord on the Tenant's behalf and for
which Tenant has paid Landlord in accordance with this Lease, shall remain the
property of the Tenant for the Lease Term. Such Alterations shall not be removed
from the Premises. At the expiration or termination of this Lease Term, all such
Alterations become the property of the Landlord; provided, however, Landlord may
require that Tenant, at Tenant's sole cost, remove any such Alterations or
utility installations at the expiration of the Lease Term and to restore the
Premises to their prior condition. In removing any such Alterations as may be
required by the Landlord, the Tenant shall remove any of its personal property
and shall repair any damage to the Premises caused by such removal and, prior to
such removal, Tenant shall post a bond or other security as may be required by
the Landlord in order to insure the Landlord that the Premises will be repaired
in a prompt and workmanlike manner. If Tenant fails promptly to commence and
diligently pursue to completion such removal and restoration required by the
provisions of this Article 17, Tenant shall pay to Landlord the cost of such
removal and restoration, such cost to include a reasonable charge for Landlord's
overhead. Tenant shall continue to pay Rent for the portion of the Premises not
completely vacated during such time together with all costs and expenses
incurred by Landlord in removing, storing and disposing of such property
together with all costs and expenses of repair to and clean up of the Premises.
Thereafter, Landlord may retain or dispose of in any manner the personal
property not so removed, without liability to Tenant.

         17.3 ABANDONED PROPERTY. Any property of Tenant not removed by Tenant
upon the expiration of the Lease Term (or within two (2) days after a
termination by reason of Tenant's default) shall be considered abandoned, and
Landlord may remove any or all such items and dispose of the same in any manner
or store the same in a public warehouse or elsewhere for the account of and at
the expense and risk of Tenant. If Tenant shall fail to pay the cost of storing
any such property after it has been stored for a period of thirty (30) days or
more, Landlord may sell any or all of such property at public or private sale,
in such manner and at such times and places as Landlord, in its sole discretion,
may deem proper, without notice to or demand upon Tenant. Landlord shall apply
the proceeds of such

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<PAGE>   38

sale (a)first, to the costs and expenses of such sale, including reasonable
attorneys' fees actually incurred; (b) second, to the payment of the expense of
or charges for removing and storing any such property; and (c) the balance to
Landlord.

         17.4 LANDLORD'S ACTIONS ON PREMISES. Tenant hereby waives all claims
for damages or other liability in connection with Landlord's re-entering and
taking possession of the Premises or removing, retaining, storing or selling the
property of Tenant as herein provided, and Tenant hereby indemnifies and holds
Landlord and Landlord's Indemnitees harmless from any such damages or other
liability, and no such re-entry shall be considered or construed to be a
forcible entry.

         17.5 HOLDING OVER. Tenant shall vacate the Premises upon the expiration
or earlier termination of this Lease. Tenant shall reimburse Landlord for and
indemnify Landlord and Landlord's Indemnitees against all damages incurred by
Landlord from any delay by Tenant in vacating the Premises. If Tenant remains in
possession of all or any part of the Premises after the expiration of the Lease
Term with or without the express or implied consent of Landlord, such tenancy
shall be from month-to-month only and not a renewal hereof or an extension for
any further term, and in such case, Base Monthly Rent then in effect shall be
increased by fifty percent (50%) and other monetary sums due hereunder shall be
payable in the amount and at the time specified in this Lease, and such
month-to-month tenancy shall be subject to every other term, covenant and
agreement contained herein, except that the month-to-month tenancy will be
terminable on thirty (30) days notice given at any time by either party.

                      ARTICLE 18 - MISCELLANEOUS PROVISIONS


         18.1 RIGHT OF FIRST REFUSAL. Commencing with the Lease Date and
continuing until the Lease Term expires or is terminated, Tenant shall have the
right to lease all or any portion of the office building in the Project
identified as "Building C" on the site plan on the same terms and conditions 
that Landlord has received a bona fide offer for such a lease ("Right of First
Refusal") if Landlord, in its sole and absolute discretion, elects to construct
Building C. Promptly upon Landlord's receipt of a written offer to lease all or
any portion of Building C, Landlord shall deliver to Tenant a copy of such
offer. Landlord shall also use its reasonable, good faith efforts to inform
Tenant of serious inquiries from a bona fide purchaser of the Building or, if
Tenant is then an occupant of any portion of Building C, Building C. Tenant
shall have five (5) Business Days after receipt of an offer in which to exercise
its Right of First Refusal. If Tenant elects to exercise its Right of First
Refusal, Tenant must deliver written notice to Landlord within such five (5)
Business Day period stating unconditionally that Tenant will enter into a lease
on the same terms and conditions as contained in the offer. If Tenant fails to
exercise its Right of First Refusal or fails to timely notify Landlord within
such five (5) Business Day period, then Tenant shall be deemed to have declined
to exercise its right and Landlord shall be free to enter into a lease of that
portion of Building C specified in the offer. In the event that Landlord does
not enter into a lease which is substantially similar to the offer delivered to
Tenant within six (6) months thereafter, Tenant's Right of First Refusal shall
be deemed to be applicable again to any and all future bona fide offers to lease
Building C received by Landlord during the Term of the Lease. Notwithstanding
any other provision of this Lease, the Right of First Refusal is personal to
Triteal Corporation and Triteal Corporation may not assign or otherwise transfer
the Right of First Refusal to any other person or entity except in conjunction
with a Transfer to an Affiliate. If a Transfer to an Affiliate is made, any and
all such Affiliates (or other Affiliates pursuant to future Transfers) shall
also be prohibited from assigning the Right of First Refusal to any other person
or entity except in conjunction with a Transfer to another Affiliate.

         18.2 SUCCESSORS; NO THIRD PARTY BENEFICIARIES. Subject to limitations
expressed elsewhere in this Lease, all rights and liabilities herein given to,
or imposed upon, the respective parties hereto shall extend to and bind the
several respective heirs, executors, administrators, successors, and assigns of
the said parties; and if there shall be more than one Tenant, they shall all be
bound jointly and severally by the terms, covenants and agreements herein. No
rights, however, shall inure to the benefit of any assignee of Tenant unless the
assignment to such assignee has been approved by Landlord in writing as provided
in Article 12 hereof. This Lease grants certain rights and imposes certain
obligations by and between Landlord and Tenant only, and there are no third
party beneficiaries of the agreement contained herein.

4/15/97                                               Landlord Initials: _______
                                   29                   Tenant Initials: _______
<PAGE>   39

         18.3 SEVERABILITY. A determination by a court of competent jurisdiction
that any provision of this Lease or any part thereof is illegal or unenforceable
shall not cancel or invalidate the remainder of such provision or this Lease,
which shall remain in full force and effect.

         18.4 INTERPRETATION. The captions of the Articles or Sections of this
Lease are to assist the parties in reading this Lease and are not a part of the
terms or provisions of this Lease. Whenever required by the context of this
Lease, the singular shall include the plural and the plural shall include the
singular. The masculine, feminine and neuter genders shall each include the
other. In any provision relating to the conduct, acts or omissions of Tenant,
the term "Tenant" shall include Tenant's agents, employees, contractors,
invitees, successors or others using the Premises with Tenant's expressed or
implied permission.

         18.5 OTHER TENANCIES. Landlord reserves the absolute right to effect
such other tenancies in the Project as Landlord, in the exercise of its sole
business judgment, shall determine to best promote the interest of the Project.
Tenant does not rely on the fact, nor does Landlord represent, that any specific
tenant or type or number of tenants shall, during the term of this Lease, either
(i)enter into a lease for any space in the Project or (ii)continue to lease any
space in the Project under any lease which is in effect as of the date of this
Lease, or that any tenant under any lease in effect as of the date of this Lease
will not assign or transfer its interest under its lease or change the use of
the premises under such lease. By executing this Lease, Tenant acknowledges that
Landlord has not made any representations, warranties or statements as to any of
the foregoing and agrees that the occurrence of any of the foregoing or any
similar event shall not affect Tenant's obligations under this Lease.

         18.6 ENTIRE AGREEMENT. Any Exhibits attached hereto shall be
incorporated herein as though fully set forth herein. This Lease and the
Exhibits, if any, attached hereto and forming a part hereof, set forth all the
covenants, promises, agreements, conditions and understandings, either oral or
written, between Landlord and Tenant concerning the Premises and there are no
covenants, promises, agreements, conditions or understandings, either oral, or
written, between them other than are herein set forth, including the Option to
Lease. Except as herein otherwise provided, no subsequent alteration, amendment,
change or addition to this Lease shall be binding upon Landlord or Tenant unless
reduced to writing and signed by the party to be charged with their performance.

         18.7 LANDLORD'S LIABILITY. As used in this Lease, the term "Landlord"
means only the current owner or owners of the fee title to the Premises or the
leasehold estate under a ground lease of the Premises at the time in question.
Each Landlord is obligated to perform the obligations of Landlord under this
Lease only during the time such Landlord owns such interest or title. Any
Landlord who transfers its title or interest is relieved of all liability with
respect to the obligations of Landlord under this Lease to be performed on or
after the date of transfer. However, each Landlord shall deliver to its
transferee all funds previously paid by Tenant if such funds have not yet been
applied under the terms of this Lease. The obligations of Landlord under this
Lease do not constitute personal obligations of Landlord, or its partners,
directors, employees, officers, members, managers or shareholders and Tenant
shall look solely to the Project and to no other assets of Landlord for
satisfaction of any liability with respect to this Lease and will not seek
recourse against the partners, directors, officers, members, managers or
shareholders of Landlord herein, nor against any of their personal assets for
such satisfaction.

         18.8 NOTICES. All notices required or permitted under this Lease shall
be in writing and shall be personally delivered or sent by certified mail,
return receipt requested, postage prepaid or by overnight courier marked for
delivery next Business Day. Notices to Tenant shall be delivered to the address
specified in Item 5 of the Basic Terms, except that upon Tenant's taking
possession of the Premises, the Premises shall be Tenant's address for notice
purposes. Notices to Landlord shall be delivered to the address specified in
Item 3 of the Basic Terms or such other address as may be instructed by
Landlord. All notices shall be effective upon personal delivery or three (3)
Business Days after deposit in the U.S. Mail or one (1) Business Day after
deposit with an overnight courier.

         18.9 WAIVERS. All waivers must be in writing and signed by the waiving
party. Landlord's failure to enforce any provision of this Lease or its
acceptance of Rent shall not be a waiver and shall not prevent Landlord from
enforcing that provision or any other provision of this Lease in the future. No
statement on a payment check from Tenant or in a letter accompanying a payment
check shall be binding on Landlord. Landlord may, with or without

4/15/97                                               Landlord Initials: _______
                                   30                   Tenant Initials: _______
<PAGE>   40

notice to Tenant, negotiate such check without being bound to the conditions of
such statement.

         18.10 NO RECORDATION. Tenant shall not record this Lease or a
memorandum hereof without prior written consent from Landlord. However, Landlord
may require that a "Short Form" memorandum of this Lease be executed by both
parties and recorded.

         18.11 CHOICE OF LAW. The internal laws without regard to choice of law
rules of the State of California shall govern this Lease.

         18.12 CORPORATE AUTHORITY; PARTNERSHIP AUTHORITY. If Tenant is a
corporation, each person signing this Lease on behalf of Tenant represents and
warrants that he or she has full authority to do so and that this Lease binds
the corporation. Concurrently with execution of this Lease, Tenant shall deliver
to Landlord a certified copy of a resolution of Tenant's Board of Directors
authorizing the execution of this Lease or other evidence of such authority
reasonably acceptable to Landlord. If Tenant is a partnership, each person
signing this Lease for Tenant represents and warrants that he or she is a
general partner of the partnership, that he or she has full authority to sign
for the partnership and that this Lease binds the partnership and all general
partners of the partnership. Tenant shall give written notice to Landlord of any
general partner's withdrawal or addition. Concurrently with execution of this
Lease, Tenant shall deliver to Landlord a copy of Tenant's recorded statement of
partnership or certificate of limited partnership.

         18.13 NO PARTNERSHIP. Landlord shall not by virtue of this Lease, in
any way or for any purpose, be deemed to have become a partner of Tenant in the
conduct of its business, or otherwise, or joint venturer or a merger of a joint
enterprise with Tenant, nor is Tenant an agent of Landlord for any reason
whatsoever.

         18.14 JOINT AND SEVERAL LIABILITY. All parties signing this Lease as
Tenant shall be jointly and severally liable for all obligations of Tenant.

         18.15 ATTORNEYS' FEES. If either party commences litigation against the
other for the specific performance of this Lease, the interpretation of this
Lease, for damages for the breach hereof or otherwise for enforcement of any
remedy hereunder, the parties hereto agree to and hereby do waive any right to a
trial by jury and, in the event of any such commencement of litigation, the
prevailing party shall be entitled to recover from the other party such costs
and reasonable attorneys' fees as may have been incurred. Further, if Landlord
is named as a defendant in any suit brought against Tenant in connection with or
arising out of Tenant's occupancy hereunder, Tenant shall be obligated to pay to
Landlord, in addition to all other amounts for which Tenant is obligated
hereunder, all of Landlord's reasonable costs and expenses incurred in
connection with any such acts, including reasonable attorneys' fees. Any
attorneys' fees incurred in enforcing any right of indemnity set forth in this
Lease shall be recoverable and deemed to be within the scope of such indemnity
and/or this attorneys' fees provision.

         18.16 LENDER MODIFICATION. If, in connection with obtaining any loans
including but not limited to a construction loan, permanent financing or
refinancing for the Project, a lender shall request reasonable modifications to
this Lease as a condition to such financing, Tenant will not unreasonably
withhold, delay or defer its consent thereto, provided that such modifications
do not increase the obligations of Tenant hereunder or materially adversely
affect the leasehold interest hereby created or Tenant's rights hereunder.

         18.17 BROKERS. Except as specifically set forth herein, nothing
contained herein shall impose upon Landlord any obligation to pay any commission
or payment to Tenant's Broker specified in Item 12 of the Basic Terms. Landlord
shall pay Landlord's Broker pursuant to a separate agreement. Landlord shall be
responsible for paying a commission to Tenant's Broker in an amount equal to
four percent (4%) of Base Monthly Rent due for Lease Years one through five,
plus two percent (2%) of Base Monthly Rent due for Lease Years six through ten;
provided, however, that such commission payable to Tenant's Broker shall be
deemed earned only at the rate of fifty percent (50%) upon the mutual execution
of the Lease and fifty percent (50%) upon the Commencement Date. If and to the
extent Landlord owes a commission to Tenant's Broker as aforesaid, Landlord
shall pay such commission fifty percent (50%) upon Landlord's obtaining a
construction loan for construction of the Building, and fifty percent (50%) upon

4/15/97                                               Landlord Initials: _______
                                   31                   Tenant Initials: _______
<PAGE>   41

the Commencement Date. Landlord and Tenant hereby warrant to each other that
they have had no dealings with any real estate broker or agent in connection
with the negotiation of this Lease, excepting only the real estate brokers or
agents specified in Item 12 of the Basic Terms, and that they know of no other
real estate broker or agent who may be entitled to a commission in connection
with this Lease. Each party agrees to indemnify and defend the other party
against and hold the other party harmless from any and all claims, demands,
losses, liabilities, lawsuits, judgments, and costs and expenses (including,
without limitation, reasonable attorneys' fees) with respect to any leasing
commission or equivalent compensation alleged to be owing on account of the
indemnifying party's dealings with any real estate broker or agent other than
that specified herein.

         18.18 FORCE MAJEURE. If Landlord or Tenant cannot perform any of their
obligations due to events beyond their reasonable control, the time provided for
performing such obligations shall be extended by a period of time equal to the
duration of such events. Events beyond Landlord's control include, but are not
limited to, acts of God, war, civil commotion, labor disputes, strikes, fire,
flood or other casualty, shortages of labor or material, government regulation
or restriction and weather conditions. Notwithstanding any provision in this
Lease to the contrary, Tenant shall be required to make each and every payment
of Rent in a timely fashion, and the due date for such payment shall not be
extended for events of force majeure or otherwise.

         18.19 TENANT OBLIGATIONS SURVIVE TERMINATION. All obligations of Tenant
hereunder not fully performed as of the expiration or earlier termination of the
Lease Term shall, survive the expiration or earlier termination of the Lease
Term, including, without limitation, all payment obligations and all obligations
concerning the condition of the Premises.

         18.20 TENANT'S WAIVER. Any claim which Tenant may have against Landlord
for default in performance of any of the obligations herein contained to be kept
and performed by Landlord shall be deemed waived unless such claim is asserted
by written notice thereof to Lessor within forty-five (45) days of Tenant's
knowledge of the alleged default or of accrual of the cause of action and unless
suit be brought thereon within six (6) months subsequent to the accrual of such
cause of action.

         18.21 SUBMISSION OF LEASE. Submission of this instrument for
examination or signature by Tenant does not constitute a reservation of or an
option for lease, and it is not effective as a lease or otherwise until
execution and delivery by both Landlord and Tenant.

                              LANDLORD:

Dated:_____________________   MARCO PLAZA ENTERPRISES, a
                              California general partnership

                              By:        /s/ Robert Kronick
                                 ----------------------------------------------
                              Name:      Robert Kronick
                                   --------------------------------------------
                              Title:     Partner
                                    -------------------------------------------

                              TENANT:

Dated:____________________    TRITEAL CORPORATION, a
                              Delaware corporation

                              By:        /s/ Gregory Jay White
                                 ----------------------------------------------
                              Name:      Gregory Jay White
                                   --------------------------------------------
                              Title:     Chief Operating Officer
                                    -------------------------------------------

                              By:
                                 ----------------------------------------------
                              Name:
                                   --------------------------------------------
                              Title:
                                    -------------------------------------------



4/15/97                                               Landlord Initials: _______
                                   32                   Tenant Initials: _______


<PAGE>   42





                                   EXHIBIT "A"

                                    Site Plan

                              [Site Plan Graphics]





4/15/97                                               Landlord Initials: _______
                                                        Tenant Initials: _______

                                   EXHIBIT "A"


<PAGE>   43

                                                                              


                                   EXHIBIT "B"

                              RULES AND REGULATIONS


         1. WALKWAYS. The sidewalks, roadways, and other public portions in the
Project shall be used by the Tenant for the purpose solely of ingress and egress
to and from the Premises of the Tenant. Tenant, its employees and agents, shall
not loiter in the entrances or corridors, nor in any way obstruct the sidewalks,
halls, stairways or elevators, and shall use the same only as a means of ingress
and egress for the Premises.

         2. CONDITIONS OF PREMISES. The Tenant shall keep the interior portion 
of the Premises, to include all windows, doors, and all other glass, plate
fixtures, and trim in a clean condition. No improvements, additions, or
materials of any kind are permitted to be placed on the outside of any of the
Premises by Tenant.

         3. STORAGE OF REFUSE. All waste paper, garbage and refuse shall be kept
in the kind of container specified by Landlord, and shall be placed outside of
the Premises in specified trash containers prepared for collection in the manner
and at the times and places specified by Landlord. Landlord may implement a
recycling program and in such case, Tenant shall deposit refuse in accordance
with any requirements of such recycling program. If Landlord shall provide or
designate a service for picking up refuse and garbage, Tenant shall use same at
Tenant's cost whether billed directly or as part of Common Area Maintenance
Charges.

         4. AERIALS. No aerial shall be erected on the roof or exterior walls of
the Premises, or within the Project, without in each instance, the written
consent of the Landlord, which may be withheld in Landlord's sole discretion.
Any aerial so installed without such written consent shall be subject to removal
without notice at any time.

         5. CONDUCT. Tenant shall conduct its business in an orderly manner in
the best interests of the Project. No loudspeakers, televisions, phonographs,
radios, or other devices shall be used in a manner so as to be heard or seen
outside of the Premises without the prior written consent of the Landlord, which
may be withheld in Landlord's sole discretion.

         6. OUTSIDE AREAS. Tenant shall not place or permit any dirt or rubbish
in any Common Area or any obstruction or materials in such areas, including,
without limitation, inventory, costs or signage of any type or kind. No exterior
storage shall be allowed without permission in writing from Landlord.

         7. PARKING. Subject to the terms of the Lease, Tenant and Tenant's 
employees shall park only in those portions of the parking area designated for
that purpose by Landlord. Landlord has the right to make changes in the parking
procedures and guidelines from time-to-time, to benefit the Project, in
Landlord's sole opinion.

         8. PLUMBING. The plumbing facilities shall not be used for any purpose
other than that for which they are constructed, and no foreign substance of any
kind shall be thrown therein, and the expense of any breakage, stoppage, or
damage resulting from a violation of this provision shall be borne by Tenant,
who shall, or whose employees, agents or invitees shall have caused it.

         9. FLAMMABLE MATERIALS. The Tenant shall not keep or permit to be kept
on the Premises any flammable or combustible fluid, chemical, or explosive
material of any kind. Tenant shall not burn any trash or garbage of any kind in
or about the Premises, or the Project.

         10. AUCTIONS. Tenant shall not hold any auction, fire, or bankruptcy 
sale in the Premises.

4/15/97                                               Landlord Initials: _______
                                                        Tenant Initials: _______
                                   EXHIBIT "B"
                                   Page 1 of 2
<PAGE>   44

         11. NO ANIMALS. Tenant shall not bring into the Premises at the 
Project any animals of any type or kind, except animals necessary to assist
persons with disabilities.

         12. SAFES. Landlord shall have the right to prescribe the weight, size
and position of all safes and other heavy property brought into the Project and
also the times and manner of moving the same in and out of the Project. Safes
and other heavy objects shall, if considered necessary by Landlord, stand on
supports of such thickness as is necessary to properly distribute the weight.
Landlord will not be responsible for loss of or damage to any such safe or
property in any case. All damage done to any part of the Project, its contents,
occupants or visitors by moving or maintaining any such safe or other property
shall be the sole responsibility of Tenant and any expense of said damage or
injury shall be borne by Tenant.

         13. SAFETY PROCEDURES. Tenant shall comply with all safety, fire
protection and evacuation procedures and regulations established by Landlord or
any governmental agency.

         14. PROTECTION FROM THEFT. Tenant acknowledges that Landlord may not
provide any guard service or other security measures. In any event, Tenant shall
assume any and all responsibility for protecting the Premises from theft,
robbery and pilferage, which includes keeping doors locked and other means of
entry to the Premises closed.

         15. WAIVER BY LANDLORD. Landlord may waive any one or more of these
Rules and Regulations for the benefit of any particular tenant or tenants, but
no such waiver by Landlord shall (i)be effective unless in writing, or (ii)be
construed as a waiver of such Rules and Regulations in favor of any other tenant
or tenants, or (iii)prevent Landlord from thereafter enforcing any such Rules
and Regulations against any or all tenants of the Project.

         16. CHANGES TO RULES. Landlord reserves the right from time to time to
amend or supplement the foregoing rules and regulations, and to adopt and
promulgate additional rules and regulations applicable to the Premises. Notice
of such rules and regulations and amendments and supplements thereto, if any,
shall be given to the Tenant and Tenant agrees to comply with all such rules and
regulations upon receipt of notice. Landlord shall not be liable in any way to
Tenant for any damage or inconvenience caused by any other tenant's
non-compliance with these rules and regulations.


4/15/97                                               Landlord Initials: _______
                                                        Tenant Initials: _______
                                   EXHIBIT "B"
                                   Page 2 of 2


<PAGE>   45
                                   EXHIBIT "C"

                              WORK LETTER AGREEMENT


         MARCO PLAZA ENTERPRISES, a California general partnership ("Landlord")
and TRITEAL CORPORATION, a Delaware corporation ("Tenant") as of this ______ day
of _________________, 199____, are executing simultaneously with this Work
Letter Agreement ("Work Letter"), a written lease (the "Lease") covering the
Premises described in the Lease.

         This Work Letter defines the scope of Improvements (as defined below)
which Landlord shall be obligated to construct or install. If there is a
conflict between the terms and provisions of this Work Letter and the Lease,
this Work Letter shall control. Terms which have initial capital letters and are
not otherwise defined in this Work Letter shall have the meaning set forth in
the Lease.

         This Work Letter is a part of the Lease and shall be subject to all of
its terms and conditions, including all definitions contained therein. In
consideration of the mutual covenants hereinafter contained, Landlord and Tenant
mutually agree as set forth below.

                SECTION 1 - IMPROVEMENTS; PLANNING AND DOCUMENTS

         1.1 CONSTRUCTION. Landlord agrees to furnish all of the material, labor
and equipment as may be reasonably necessary for the construction of the
Improvements (as defined below) in a good and workmanlike manner in substantial
conformance with the Shell Plans and Specifications (as defined below) and the
T.I. Plans and Specifications (as defined below) and in compliance with all
covenants, conditions and restrictions to which the Land is subject and all
applicable building laws, ordinances, orders, rules, regulations and
requirements of any governmental agency having jurisdiction over the development
of the Land. Landlord shall use its reasonable efforts to achieve Substantial
Completion of the Improvements by the Target Commencement Date.

                  1.1.1 IMPROVEMENTS. "Improvements" shall mean the Building and
all improvements, machinery, equipment, fixtures and other property, real,
personal or mixed (excepting Tenant's trade fixtures, machinery and equipment)
installed or constructed on the Land or in the Building by Landlord (including,
without limitation, Common Area, Site Amenities, and other site improvements and
landscaping), together with all additions, alterations and replacements thereof.
Improvements shall include the Shell Improvements (as defined below) and Tenant
Improvements (as defined below) constructed by Landlord.

                  1.1.2 LAND. "Land" shall mean that portion of the Project upon
which Landlord shall construct the Building and the portions of the Common Area
as required pursuant to this Lease.

         1.2 SHELL IMPROVEMENTS.

                  1.2.1 SHELL DEFINITIONS.

                           1.2.1.1  EXTERIOR BUILDING FINISHES. "Exterior
Building Finishes" shall mean the exterior building finish materials to be
incorporated into the Building, a list of which is attached hereto as Schedule 3
and which Landlord and Tenant have reviewed and mutually believe will fall
within the Twenty-Two Dollars ($22.00) per square foot of exterior Building skin
area as contemplated by the approved Preliminary Plans and Specifications.

4/15/97                                               Landlord Initials: _______
                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                   Page 1 of 14
<PAGE>   46




                           1.2.1.2  PRELIMINARY PLANS AND SPECIFICATIONS.
"Preliminary Plans and Specifications" shall mean those preliminary plans and
specifications for the Shell Improvements, prepared by Brian Paul and
Associates, Architects and Planners ("Building Architect"), which describe and
depict the site plan and Common Area within the Building and certain preliminary
exterior elevation improvements, and which are referenced and/or described on
Schedule 2 attached hereto.

                           1.2.1.3  SHELL CONSTRUCTION DRAWINGS. "Shell
Construction Drawings" shall mean 1/4 or 1/8 scale construction drawings for the
Shell Improvements containing all information reasonably necessary to construct
the Shell Improvements, which drawings shall be reasonably consistent with the
Preliminary Plans and Specifications and shall incorporate the selected Exterior
Building Finishes.

                           1.2.1.4  SHELL IMPROVEMENTS. "Shell Improvements"
shall mean a three-story office building of steel frame construction with
finishes as may be required by the City of Carlsbad for a building shell final
inspection and mutually acceptable to Landlord and Tenant pursuant to the terms
hereof, including two finished elevators and an elevator lobby on each floor,
fire sprinkler systems (distributed with heads required for building shell final
inspection by the City of Carlsbad), emergency stairway exits, central plant for
HVAC system and an HVAC water loop for each floor, finished restrooms on each
floor, finished Common Area for fire exiting on the ground floor and finished
lobby of the ground floor from the front of the Building entrance to the
Building core and finished Common Area corridors on each floor, all such
improvements to be reasonably comparable to "Class A" standards of a suburban
office building, and substantially in conformance with the Office
Building-Outline Specifications dated January 17, 1997, attached hereto as
Schedule 1. Shell Improvements shall include the Site Amenities and those
components of the Premises which are identified in the Preliminary Plans and
Specifications as elements of the basic Building shell, or more specifically as
"Shell Improvements," land, land preparation, landscaping and all necessary
utilities stubbed to the Building, or as otherwise mutually identified by
Landlord and Tenant, in writing.

                           1.2.1.5  SHELL PLANS AND SPECIFICATIONS. "Shell Plans
and Specifications" shall mean collectively the Preliminary Plans and
Specifications, the Exterior Building Finishes Plans, the Shell Construction
Drawings, and all related plans, drawings, specifications and notes developed or
prepared in connection therewith.

                  1.2.2 PREPARATION OF SHELL IMPROVEMENT DOCUMENTS. Landlord and
Tenant have approved the Preliminary Plans and Specifications, including the
size, location and design of the Site Amenities. Any material changes to the
size, location or design of the Size Amenities shall be subject to Tenant's
prior written approval, which approval shall not be unreasonably withheld or
delayed.

                           1.2.2.1  EXTERIOR FINISHES. The Building will have a
mutually agreed upon Exterior Building Finish materials such as limestone, metal
paneling, brick veneer, glass, or granite near the entryway to conform to or be
compatible with the overall architectural theme for the Project as determined by
Landlord. Tenant acknowledges that Landlord has negotiated and agreed upon the
Base Monthly Rent and other economic terms and conditions of this Lease based
upon the assumption that the cost of the Exterior Building Finishes to be
incorporated into the Building are estimated to be Twenty-Two Dollars ($22.00)
per square foot of Building exterior skin area as set forth on Schedule3. Within
ten (10) days after the Lease Date, two (2) or more of the Exterior Building
Finishes shall be selected by Landlord and reviewed by Tenant for inclusion in
the Shell Improvements. Should either Landlord or Tenant select Exterior
Building Finishes from Schedule 3 attached hereto whose estimated composite
costs exceed Twenty-Two Dollars ($22.00) per square foot of exterior Building
skin area, such excess cost shall be at the selecting parties' expense based on
such estimated costs, without regard to whether or not the actual cost of
construction of such selected materials is less than or greater than the
estimated cost set forth on Schedule 3.

                           1.2.2.2  INPUT. Tenant will have input into the
colors, materials and quality of all


4/15/97                                               Landlord Initials: _______
                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                   Page 2 of 14
<PAGE>   47

Common Area finishing. Landlord will reasonably consider such input in making
its final determination of such colors, materials and quality of Common Area
finishing. Tenant will provide any such input within five (5) days of Landlord's
notice of an opportunity to do so.

                           1.2.2.3  PROCESS. The approval of the Exterior
Building Finishes to be included in the Shell Improvements shall be subject to
Tenant's review and approval, which approval shall not unreasonably withheld or
delayed. Tenant shall respond in writing to Landlord within five (5) days of
receipt of any selection of Exterior Building Finishes, specifying its approval
or reasonable changes to the materials selected, if any. Failure of Tenant to
respond within said five (5) day period shall be deemed Tenant's approval of
Landlord's selection of Exterior Building Finishes so submitted. If Tenant
requests revisions to the Exterior Building Finishes selected in conformance
with the terms of this Work Letter, Landlord shall incorporate such reasonable
revisions subject to Tenant's agreement to pay any excess estimated composite
costs as set forth above.

                           1.2.2.4  SHELL CONSTRUCTION DRAWINGS. As soon as is
reasonably practicable following the designation of the Exterior Building
Finishes, Landlord shall prepare the Shell Construction Drawings in substantial
conformance with the Preliminary Plans and Specifications and incorporating the
approved Exterior Building Finishes.

         1.3      TENANT IMPROVEMENTS.

                  1.3.1    TENANT DEFINITIONS.

                           1.3.1.1  DESIGN DEVELOPMENT DRAWINGS. "Design
Development Drawings" shall mean reasonably detailed preliminary construction
drawings for the Tenant Improvements, which drawings shall be reasonably
consistent with the approved Schematic Design Drawings.

                           1.3.1.2  SCHEMATIC DESIGN DRAWINGS. "Schematic Design
Drawings" shall mean reasonably detailed and dimensioned 1/8 scale preliminary
schematic design drawings for the Tenant Improvements, which drawings are
reasonably consistent with the approved Space Plan.

                           1.3.1.3  SPACE PLAN. "Space Plan" shall mean a floor
by floor layout designation of all counters, fixtures, demising walls and
partitions, and other equipment to be included in the Building as the Tenant
Improvements. The Space Plan shall be prepared by the Futas Design Group or as
otherwise selected by Tenant in its reasonable discretion.

                           1.3.1.4  TENANT IMPROVEMENTS. "Tenant Improvements"
shall mean all those portions of the Premises which are identified in the Space
Plan and which are the responsibility of Landlord's Contractor, or as otherwise
mutually identified by Landlord and Tenant, in writing. The Tenant Improvements
shall be based on the approved Space Plan.

                           1.3.1.5  T.I. CONSTRUCTION DRAWINGS. "T.I.
Construction Drawings" shall mean 1/4 or 1/8 scale construction drawings for the
Tenant Improvements containing all information reasonably necessary to construct
the Tenant Improvements, which drawings shall be reasonably consistent with the
approved Design Development Drawings.

                           1.3.1.6  T.I. PLANS AND SPECIFICATIONS. "T.I. Plans
and Specifications" shall mean collectively the Space Plan, Schematic Design
Drawings, Design Development Drawings, and T.I. Construction Drawings, and all
related plans, drawings, specifications and notes developed or prepared in
connection therewith.

4/15/97                                               Landlord Initials: _______
                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                   Page 3 of 14
<PAGE>   48


                  1.3.2    PLANNING; PREPARATION OF TENANT IMPROVEMENT
                           DOCUMENTS.

                           1.3.2.1  SPACE PLAN. Concurrently with the execution
of this Work Letter, Tenant shall cause the Space Plan to be prepared in
accordance with this Work Letter. Landlord will have the right to reasonably
review and approve the draft Space Plan. Tenant shall submit the proposed Space
Plan to Landlord for Landlord's review and approval, which approval shall not be
unreasonably withheld or delayed. Landlord shall respond in writing to Tenant
within ten (10) days of receipt of any portion of the Space Plan specifying its
approval or reasonable changes to the plans submitted, if any. Failure of
Landlord to respond within said ten (10) day period shall be deemed Landlord's
approval of the Space Plan so submitted. If Landlord requests reasonable
revisions to the Space Plan in conformance with the terms of this Lease, Tenant
shall revise said documents and resubmit them to Landlord for its review and
approval. Failure of Landlord to respond within ten (10) days shall be deemed
Landlord's approval on the revised Space Plan so submitted. The foregoing
process shall continue until the Space Plan is approved. Notwithstanding any
provision in this Work Letter to the contrary, Tenant shall be responsible for
producing a final Space Plan approved by Landlord no later than May 23, 1997.
Tenant acknowledges that Landlord is relying on Tenant's timely delivery of the
final approved Space Plan in order to allow Landlord to Substantially Complete
the Premises by the Target Commencement Date. Accordingly, for each day which
passes after the foregoing date and before an approved Space Plan is delivered
to Landlord, the Target Commencement Date shall be delayed the same number of
days.

                           1.3.2.2  SCHEMATIC DESIGN DRAWINGS. As soon as is
reasonably practicable following Landlord's approval of the Space Plan, Tenant
shall submit to Landlord proposed Schematic Design Drawings. The Schematic
Design Drawings shall be subject to the approval of Landlord, which approval
shall not be unreasonably withheld or delayed. Landlord shall respond in writing
to Tenant within ten (10) days of receipt of any portion of the Schematic Design
Drawings specifying its approval or disapproval thereof. Landlord may only
disapprove proposed Schematic Design Drawings if they do not substantially
conform to the approved Space Plan. If Landlord disapproves any portion of the
Schematic Design Drawings, then Landlord shall, timely and specifically and in
writing, (a) approve those portions which are acceptable to Landlord, and
(b)disapprove those portions which are not acceptable to Landlord, specifying
the reasons for such disapproval and describing in detail the change Landlord
requests for each item disapproved. Failure of Landlord to respond within said
ten (10) day period shall be deemed Landlord's approval of the Schematic Design
Drawings so submitted. In the event the Schematic Design Drawings have been
disapproved by Landlord, and Tenant and Landlord are unable to resolve
Landlord's disapproval after good faith efforts to do so over a period of ten
(10) Business Days after delivery of Landlord's notice disapproving Schematic
Design Drawings, Landlord and Tenant shall submit their disagreement to the
dispute resolution procedure described in Section 1.3.2.5 below.

                           1.3.2.3  DESIGN DEVELOPMENT DRAWINGS. As soon as is
reasonably practicable following approval of the Schematic Design Drawings,
Tenant shall submit to Landlord proposed Design Development Drawings. The Design
Development Drawings shall be subject to the approval of Landlord, which
approval shall not be unreasonably withheld or delayed. Landlord shall respond
in writing to Tenant within ten (10) days of receipt of any portion of the
Design Development Drawings. Landlord may only disapprove proposed Design
Development Drawings if they do not substantially conform to the approved
Schematic Design Drawings. If Landlord disapproves any portion of the Design
Development Drawings, then Landlord shall, timely and specifically and in
writing, (a) approve those portions which are acceptable to Landlord, and (b)
disapprove those portions which are not acceptable to Landlord, specifying the
reasons for such disapproval and describing in detail the change Landlord
requests for each item disapproved. Failure of Landlord to respond within said
ten (10) day period shall be deemed Landlord's approval of the Design
Development Drawings so submitted. In the event the Design Development Drawings
have been disapproved by Landlord, and Tenant and Landlord are unable to resolve
Landlord's disapproval after good faith

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                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                   Page 4 of 14
<PAGE>   49

efforts to do so over a period of ten (10) Business Days after delivery of
Landlord's notice disapproving the Design Development Drawings, Landlord and
Tenant shall submit their disagreement to the dispute resolution procedure
described in Section 1.3.2.5 below.

                           1.3.2.4  T.I. CONSTRUCTION DRAWINGS. As soon as is
reasonably practicable following approval of the Design Development Drawings,
Tenant shall submit to Landlord proposed T.I. Construction Drawings. The T.I.
Construction Drawings shall be subject to the approval of Landlord, which
approval shall not be unreasonably withheld or delayed. Landlord shall respond
in writing to Tenant within ten (10) days of receipt of any portion of the T.I.
Construction Drawings. Landlord may only disapprove the T.I. Construction
Drawings if they do not substantially conform to the approved Design Development
Drawings. If Landlord disapproves any portion of the T.I. Construction Drawings,
then Landlord shall, timely and specifically and in writing, (a) approve those
portions which are acceptable to Landlord, and (b) disapprove those portions
which are not acceptable to Landlord, specifying the reasons for such
disapproval and describing in detail the change Landlord requests for each item
disapproved. The failure of Landlord to respond within said ten (10) day period
shall be deemed Landlord's approval of the T.I. Construction Drawings so
submitted. In the event the T.I. Construction Drawings have been disapproved by
Landlord, and Tenant and Landlord are unable to resolve Landlord's disapproval
after good faith efforts to do so over a period of ten (10) Business Days after
delivery of Landlord's notice disapproving the T.I. Construction Drawings,
Landlord and Tenant shall submit their disagreement to the dispute resolution
procedure described in Section 1.3.2.5 below. Notwithstanding any provision of
this Work Letter to the contrary, Tenant shall be responsible for delivering
final T.I. Construction Drawings approved by Landlord no later than August 1,
1997. Tenant acknowledges that Landlord is relying on Tenant's timely delivery
of the final approved T.I. Construction Drawings in order to allow Landlord to
timely deliver the Premises on the Target Commencement Date. Accordingly, for
each day which passes after the foregoing date and before approved T.I.
Construction Drawings are delivered to Landlord, the Target Commencement Date
shall be delayed the same number of days.

                           1.3.2.5  DESIGN DISPUTES. In the event Landlord and
Tenant are unable to resolve Landlord's disapproval of a phase of the
development of the T.I. Plans and Specifications as described in Sections
1.3.2.2, 1.3.2.3, and 1.3.2.4 above (a "Design Dispute"), they shall resolve
those differences through the binding arbitration of a neutral third-party in
accordance with this provision. In the event of a Design Dispute, Landlord and
Tenant shall meet within three (3) days to make a good faith attempt to mutually
appoint a single party who shall be a licensed architect ("Arbitrating
Architect"), with not less than ten (10) years experience in commercial and
industrial architecture and who is not then employed or otherwise previously
affiliated with either party, to arbitrate their differences and resolve the
Design Dispute. If Landlord and Tenant are unable to agree upon a single
Arbitrating Architect, then each shall, within two (2) Business Days after the
meeting, select an architect that meets the foregoing qualifications. The two
(2) architects so appointed shall, within two (2) Business Days after their
appointment, appoint a third architect meeting the foregoing qualifications who
shall serve as the Arbitrating Architect. If the two (2) architects so selected
cannot agree on the selection of the Arbitrating Architect within the time above
specified, then either party, on behalf of both parties, may request appointment
of the Arbitrating Architect by the Presiding Judge of the San Diego Superior
Court. The procedures for arbitrating and resolving the Design Dispute shall be
established by the Arbitrating Architect in a manner designed to promptly
resolve the Design Dispute. The determination of the Arbitrating Architect shall
be limited solely to the issue of the Design Dispute and shall be made within
ten (10) Business Days of its submission by the parties for arbitration. The
decision of the Arbitrating Architect shall be binding on both parties. The cost
of the arbitration, including, without limitation, attorneys' fees and costs,
witness fees, expert witness fees, and costs of the arbitration proceeding, may
be awarded by the Arbitrating Architect to the prevailing party. The
non-prevailing party shall be charged with any time delays caused by the Design
Dispute. In the event of any judicial enforcement or confirmation proceeding
relating to an arbitration award for a Design Dispute, the prevailing party
shall be entitled to recover from the other party all related costs, including
reasonable attorneys' fees and costs.

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                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                   Page 5 of 14
<PAGE>   50

                           1.3.2.6  OWNERSHIP. Notwithstanding the fact that
Tenant is responsible for developing all phases of the approved T.I. Plans and
Specifications, the parties have agreed that, by execution hereof, Tenant is
assigning to Landlord all of Tenant's right, title and interest in and to the
ownership of the T.I. Plans and Specifications.

         1.4 BUILDING PERMITS. Landlord shall be responsible for obtaining from
any relevant and jurisdictional governmental authority all governmental
approvals necessary for the construction of the Shell Improvements, including a
building permit. Tenant shall be responsible for obtaining from any relevant and
jurisdictional governmental authority all governmental approvals necessary for
the construction of the Tenant Improvements, including a building permit.
Landlord shall be responsible for the payment of the building permit fees for
the Shell Improvements and, pursuant to the Tenant Improvement Allowance and/or
the Tenant Contingency Allowance, Landlord shall also be responsible for the
payment of the building permit fees for the Tenant Improvements. If a change to
the approved Shell Plans and Specifications or T.I. Plans and Specifications is
required by any governmental authority as a condition to obtaining a building
permit, such change shall be made to the Shell Plans and Specifications and/or
T.I. Plans and Specifications and deemed to have been approved by Landlord
and/or Tenant, as appropriate. Any change to the approved Shell Plans and
Specifications which is not mandated by a governmental authority shall be
subject to Tenant's reasonable review and approval. Tenant shall negotiate in
good faith for the allocation of any increase in construction costs due to such
a change. The costs associated with any such changes related to the Shell
Improvements shall be Landlord's responsibility and related to the Tenant
Improvements shall be Tenant's responsibility. The parties shall cooperate with
each other as may be reasonably necessary to obtain the building permit and any
and all other permits, as appropriate. Notwithstanding any provision of this
Work Letter or the Lease to the contrary, Tenant shall obtain the necessary
building permits for the approved T.I. Plans and Specifications no later than
November 7, 1997. Tenant acknowledges that Landlord is relying upon Tenant's
timely acquisition of the Tenant Improvements building permits so that Landlord
may Substantially Complete the Premises by the Target Commencement Date.
Accordingly, for each day which passes after the foregoing date and before all
building permits for the Tenant Improvements are obtained and delivered to
Landlord, the Target Commencement Date shall be delayed the same number of days.

         1.5 CONDITION OF PREMISES: LIMITATION. Except as specifically provided
in this section, Landlord makes no warranties or representations with regard to
the Premises or the Improvements, or any portion thereof, and Tenant shall
accept the Premises in the condition in which they are delivered on the
Commencement Date; provided, however, that the Premises shall be constructed in
substantial conformance with the approved T.I. Plans and Specifications and in
accordance with all applicable laws then in effect. Landlord makes no warranty
to Tenant regarding any other aspect of the Improvements or the Premises,
including but not limited to, any patent or latent defects, which Tenant
expressly waives any rights to make claims therefore; provided, however, that
Landlord hereby assigns to Tenant on a nonexclusive basis all guarantees and
warranties from any contractors, subcontractors, materialmen and suppliers which
provide construction, labor or materials to the Premises.

         1.6 APPROVALS. After Landlord's approval of any of the T.I. Plans and
Specifications and/or Tenant's approval of the Exterior Building Finishes, no
significant changes, modifications or alterations may be made without the prior
written consent of both Landlord and Tenant; provided, however, if any changes
are required (i) by any governmental agency with jurisdiction over the Project,
(ii) as a result of field conditions, or (iii) to substitute reasonably
equivalent materials to avoid unanticipated delays, strikes or shortages, then
Landlord shall be authorized to make such changes. The costs of any such changes
to the T.I. Plans and Specifications are to be included within the Total Cost
(as hereinafter defined). Any changes to the T.I. Plans and Specifications
and/or the Exterior Building Finishes Plans after approval thereof, other than
any changes required under Subsections (i), (ii) and (iii) above, shall
constitute a Change Order (as hereinafter defined).


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                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                   Page 6 of 14
<PAGE>   51

         1.7 COSTS. All costs and fees associated with the preparation of the
Shell Plans and Specifications, including, without limitation, all consultant or
subcontractor design fees, and all costs of constructing the Shell Improvements
shall be borne solely by Landlord, except as expressly set forth herein.
Notwithstanding the foregoing, in the event Tenant selects Exterior Building
Finishes pursuant to Section 1.3.1 above whose estimated composite costs as set
forth on Schedule 3 exceed Twenty-Two Dollars ($22.00) per square foot of
Building exterior skin area, such excess costs may be paid in a lump cash sum by
Tenant or, up to the amount set forth herein, be subject to the Tenant
Contingency Allowance set forth in Section 3.2 below. Shell Plans and
Specifications shall be prepared by the Building Architect and other consultants
selected by Landlord in its sole discretion. T.I. Plans and Specifications shall
be prepared by Futas Design Group and other consultants selected by Tenant and
reasonably approved by Landlord.

                         SECTION 2 - TENANT IMPROVEMENTS

         2.1 TENANT IMPROVEMENTS. The Tenant Improvements are and shall remain 
Landlord's property and shall be surrendered to Landlord upon expiration or 
earlier termination of the Lease in accordance with the provisions of the Lease.

         2.2 PREMISES FURNISHINGS. It is expressly understood that Landlord's
obligation to construct Tenant Improvements in the Premises is limited to
construction of the Tenant Improvements specifically contemplated by the T.I.
Plans and Specifications. Tenant shall be solely responsible for the performance
and expense of the design, layout, provision, delivery and installation of any
furniture, furnishings, equipment, and any other personal property Tenant will
use at the Premises. In arranging for the performance of any of the work
referred to in the preceding sentence, Tenant shall be permitted to enter the
Premises only upon the prior consent of Landlord and shall adopt a schedule in
conformance with the schedule(s) of Landlord's Contractor (as hereinafter
defined) and conduct its work in such a manner as to maintain harmonious labor
relations so as not to interfere unreasonably with or delay the work of
Landlord's contractors in substantially completing the Tenant Improvements.

                    SECTION 3 - TENANT IMPROVEMENT ALLOWANCE

         3.1 TENANT IMPROVEMENT ALLOWANCE. Landlord has agreed to contribute a
one-time tenant improvement allowance for the cost of preparing the T.I. Plans
and Specifications related to Tenant Improvements and toward the cost of
constructing the Tenant Improvements, including any necessary permits and
demolition work in an amount up to the amount specified in Item 15 of the Basic
Terms of the Lease ("Tenant Improvement Allowance"). The Tenant Improvement
Allowance is based on the Usable square feet of the Premises, and the
calculation of usable square feet for the Premises shall be mutually agreed to
by the Building Architect and Futas Design Group. Tenant shall be solely
responsible for any and all costs of constructing the Tenant Improvements in
excess of the Tenant Improvement Allowance pursuant to the provisions of Section
3.2 and Section 3.3 below. The total of all costs incurred by Landlord in
connection with the design and construction of the Tenant Improvements shall be
referred to as the "Total Costs."

                  3.1.1 ALLOCATION. Notwithstanding Section 3.1 above, the
parties have agreed that certain portions of Tenant Improvement Allowance may
only be used for certain portions of the Tenant Improvements. Such allocations
are as follows: (a) a minimum of Twenty-Two Dollars ($22.00) per usable square
foot of the Tenant Improvement Allowance shall be used for building standard
tenant improvements as described on Schedule 4 attached hereto and incorporated
herein; (b) a maximum of Two Dollars Fifty Cents ($2.50) per Usable square foot
of the Tenant Improvement Allowance shall be used for architecture and
engineering fees; (c) a maximum of One Dollar ($1.00) per Usable square foot of
the Tenant Improvement Allowance shall be used for fees and permits related to
the Tenant Improvements; and (d)the remainder of the Tenant Improvement
Allowance shall be used for Tenant Improvements which are more expensive than
building standard and for other upgrades to the Shell Improvements, or,

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                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                   Page 7 of 14
<PAGE>   52

a combination thereof, as Tenant requests in its sole discretion. Portions of
the Tenant Improvement Allowance may be utilized for nonbuilding standard Tenant
Improvements and other upgrades to the Shell Improvements if and only if Tenant
incorporates such requests into the Exterior Building Finishes or the Space
Plan, as appropriate, prior to their initial approval.

                  3.1.2 COMMON AREA. Notwithstanding Sections 3.1 and 3.1.1
above, Tenant has agreed to apply Fifty Thousand Dollars ($50,000) of the Tenant
Improvement Allowance to reimburse Landlord for constructing and finishing the
Common Area corridors in the Building, the lobby on the ground floor of the
Building, and the fire exit corridors on each floor of the Building to Class "A"
suburban office building standards (as reasonably determined by the Building
Architect and reflected in the approved Shell Plans and Specifications).

         3.2 TENANT CONTINGENCY ALLOWANCE. In the event Tenant selects Exterior
Building Finishes which are in excess of the assumed costs as set forth in
Section 1.2.2.1 above, and Tenant elects to not pay such excess in a cash lump
sum to Landlord upon Substantial Completion of the Premises, and/or the actual
cost of the Tenant Improvements exceeds either the total Tenant Improvement
Allowance or the specific allocations set forth in Section 3.1.1 above
(collectively, the "Excess Costs"), Landlord has agreed to advance payment
towards the Excess Costs in an amount up to the amount of the Tenant Contingency
Allowance specified in Item 16 of the Basic Terms of the Lease. In such event,
Tenant shall repay to Landlord as Additional Rent the amount of the Tenant
Contingency Allowance paid by Landlord. Such repayment of the Tenant Contingency
Allowance shall be at the rate of One and Forty-Three Hundredths Cents ($0.0143)
per Rentable square foot per month in the Premises for each One Dollar ($1.00)
per Rentable square foot in the Premises of Excess Cost paid by Landlord, and
adding the resulting monthly amount to the Base Monthly Rent due hereunder. For
example, and not by way of limitation, if Tenant selected Exterior Building
Finishes the cost of which exceeded the Twenty-Two Dollars ($22.00) per square
foot of Building skin area budget by Fifty-One Thousand Dollars ($51,000.00),
which Fifty-One Thousand Dollars ($51,000.00) were the total Excess Cost, then
the Base Monthly Rent due hereunder would be increased by One and Forty-Three
Hundredths Cents ($0.0143) per Rentable square foot per month (because such
Excess Cost is equal to One Dollar ($1.00) per Rentable square foot of
Premises).

         3.3 COST OF TENANT IMPROVEMENT WORK.

                  3.3.1 OBTAINING COST QUOTATION. Landlord shall retain a
contractor, acceptable to Landlord in its sole discretion ("Contractor"), as
contractor for the Tenant Improvements. The Contractor may be an affiliate of
Landlord or any of its partners. Within ten (10) days after Landlord's approval
of the T.I. Construction Documents, Landlord shall provide to Tenant the cost of
the Tenant Improvements ("Cost Quotation") based upon the approved T.I.
Construction Documents. Landlord will require the Contractor to competitively
bid all major subtrades for the Tenant Improvements construction. Landlord will
provide copies of such bids and make a recommendation to select a particular
bidder for review by Tenant. Landlord and Tenant will mutually agree on the
selection of each subtrade vendor based on such competitive bids; provided,
however, Landlord or Contractor shall not be required to include the lowest bid
for any particular trade in the Cost Quotation if, in Landlord's or Contractor's
reasonable judgment, a higher bid is more desirable for the quality of, or the
timeliness in completing, the Tenant Improvements or other qualitative
considerations such as the subtrade vendor's prior experience and availability.
If Landlord and Tenant are not able to mutually agree on each major subtrade
vendor, Landlord's selection shall be binding for all such subtrades except
finish trades such as millwork, wall coverings, and carpet, for which Tenant's
selection shall be final. Notwithstanding the foregoing, neither Landlord nor
Tenant shall be permitted to select any major subtrade vendor whose costs exceed
the lowest subtrade vendor by more than five percent (5%) unless and until the
other party mutually agrees.

                  3.3.2 APPROVAL OF COST QUOTATION BY TENANT. Tenant shall,
within five (5) Business Days of

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                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                   Page 8 of 14
<PAGE>   53

receipt thereof, either: (i) agree in writing to pay the cost by which the Cost
Quotation exceeds the sum of the Tenant Improvement Allowance and the Tenant
Contingency Allowance ("Additional Cost"), or (ii) revise the T.I. Construction
Documents or Space Plan so that the Cost Quotation is either (a) no more than
the Tenant Improvement Allowance plus Tenant Contingency Allowance, or (b) in
excess of the Tenant Improvement Allowance plus Tenant Contingency Allowance by
the amount of Additional Cost which Tenant agrees to pay. If Tenant elects to
revise the T.I. Construction Documents in order to reduce the Cost Quotation,
the period of time between Tenant's election to revise the T.I. Construction
Documents and the approval of the revised T.I. Construction Documents by Tenant
shall constitute a Tenant Delay (as defined below). If the sum of the Cost
Quotation plus the amounts described in Section 3.1.1(b) and 3.1.1(c) is less
than the maximum Tenant Improvement Allowance set forth in the Basic Terms, the
Tenant Improvement Allowance shall be deemed to be an amount equal to such sum.
The failure of Tenant to respond within the five (5) Business Day period shall
be a Tenant Delay. Upon approval by Tenant, Landlord shall be authorized to
proceed with the Improvements in accordance with the approved T.I. Construction
Documents. All costs of revising the T.I. Construction Documents, including,
without limitation, re-engineering, estimating, printing of drawings, costs of
any space planner, architect, engineering consultants and other consultants and
any other incidental expenses, shall be chargeable against the Tenant
Improvement Allowance and includable in the Total Cost.

         3.4 LANDLORD COSTS FOR TENANT IMPROVEMENTS. All costs incurred by
Landlord in connection with (a) the design, construction and installation of the
Tenant Improvements, (b) any demolition or modification of any existing
improvements as may be necessary to accomplish construction of the Tenant
Improvements in conformance with the T.I. Construction Documents, or (c) any
other measures taken by Landlord which may be reasonably required to accomplish
Landlord's construction of the Tenant Improvements, including but not limited to
Landlord's procurement of bonds, insurance policies and governmental permits,
and shall be charged against the Tenant Improvement Allowance and included
within the Total Cost; provided, however, that the cost of such construction
insurance policy shall be fixed at one percent (1%) of the Total Cost for the
Tenant Improvements.

         3.5 TENANT COSTS FOR TENANT IMPROVEMENTS. Tenant shall deliver to
Landlord at least twenty (20) days prior to the commencement of construction of
the Tenant Improvements cash equal to one hundred percent (100%) of the amount
of the Additional Costs. Tenant shall be solely responsible for all Additional
Costs.

                 SECTION 4 - CONSTRUCTION OF TENANT IMPROVEMENTS

         4.1 COMMENCEMENT OF CONSTRUCTION. Landlord intends to arrange for the
Commencement of Construction to occur on or before November 1, 1997. If
Commencement of Construction does not occur on or before November 1, 1997,
Landlord shall not in any event be liable to Tenant for damages as a result
thereof but Tenant shall have the right, as its sole and exclusive remedy, to
terminate this Lease by delivering written notice thereof to Landlord by on or
before November 5, 1997. If Tenant fails to deliver such notice of termination 
by on or before November 5, 1997, such right to terminate shall be deemed waived
and the Lease shall continue in full force and effect.

         4.2 CONSTRUCTION OF TENANT IMPROVEMENTS. After approval of the T.I.
Construction Documents, Landlord's Contractor shall use its diligent efforts to
Substantially Complete (as defined below) the Tenant Improvements on or before
the Target Commencement Date set forth in the Lease. Landlord shall enter into a
construction contract with Contractor which contains a guaranteed delivery date
for the Tenant Improvements, including a \liquidated damage penalty provision,
such date of delivery to be established after approval of the final T.I.
Construction Drawings and subject to events of force majeure. Such construction
contract with the Contractor shall specify that the cost of the general
conditions for the Improvements shall be four percent (4%) of the cost of
construction, and shall specify a profit for the Tenant Improvements of four
percent (4%) of the sum of the cost of construction and general conditions.


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                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                   Page 9 of 14
<PAGE>   54

         4.3 COMPLETION OF TENANT IMPROVEMENTS. Landlord shall be responsible
for the construction of the Tenant Improvements in substantial conformance with
the approved T.I. Construction Documents. Upon Substantial Completion (as
defined below) of the Tenant Improvements, Landlord shall provide a "punchlist"
identifying the corrective work of the type commonly found on an architectural
punchlist with respect to the Tenant Improvements, which list shall be in
Landlord's reasonable discretion based on whether such items were required by
the approved T.I. Construction Documents. Within ten (10) Business Days after
delivery of the punchlist, Landlord shall commence the correction of punchlist
items and diligently pursue such work to completion within thirty (30) days
after Substantial Completion. The punchlist procedure to be followed by Landlord
and Tenant shall in no way limit Tenant's obligation to occupy the Premises
under the Lease nor shall it in any way excuse Tenant's obligation to pay Rent
as provided under the Lease, unless such punchlist items reasonably precludes
Tenant from occupying the Premises, as reasonably determined by Landlord and
Tenant.

         4.4 MONTHLY REPORTS; SITE MEETINGS. Landlord shall provide to Tenant
monthly progress reports describing the condition and estimated schedule for
completing the Tenant Improvements ("Monthly Reports"). Landlord shall include
in the Monthly Report a comparison of then-known actual costs of the Tenant
Improvements compared to the estimated cost as reflected in the approved Cost
Quotation. In no event shall the Monthly Reports be deemed to be a
representation, warranty or an assurance by Landlord of the date of Substantial
Completion or the Total Cost of the Tenant Improvements and Tenant specifically
acknowledges that the Monthly Report is only an estimate by Landlord based on
information provided to Landlord. Landlord shall have no liability or
responsibility for any errors or inaccuracies in a Monthly Report. In addition,
Landlord and Tenant shall coordinate on-site meetings of construction personnel
as reasonably appropriate in order to implement the construction described in
this Work Letter.

         4.5 SUBSTANTIAL COMPLETION. "Substantial Completion" or "Substantially
Completed" as used herein shall mean both (a) delivery of written notice to
Tenant of the completion of construction of the Tenant Improvements in the
Premises pursuant to the approved T.I. Construction Documents with the exception
of minor details of construction installation, decoration, or mechanical
adjustments and punchlist items as certified to by Landlord, and (b) the
issuance by the City of Carlsbad of a final inspection approval, certificate of
occupancy, a temporary certificate of occupancy or some other authorization or
Tenant has occupied and obtained the beneficial use of the Premises. Substantial
Completion shall be deemed to have occurred notwithstanding the requirement to
complete "punchlist" items or similar corrective work. Tenant agrees that if
Landlord shall be delayed in causing such work to be Substantially Completed as
a result of any of the events as defined below (referred to herein as a "Tenant
Delay"), then such delay shall be the responsibility of Tenant, and will result
in the Commencement Date of the Term being the earlier of: (i) Tenant's opening
of the Premises for business; (ii) the date of Substantial Completion or (iii)
the date when Substantial Completion would have occurred if there had been no
Tenant Delay, providing that Landlord shall not be required to work on an
overtime basis in order to bring the Premises to Substantial Completion. For the
purposes of this Work Letter, a Tenant Delay is defined as follows: (a) Tenant's
failure to comply with any time frames set forth herein or in the Lease, (b) any
changes in any stage of the T.I. Plans and Specifications requested by Tenant
after Landlord's and Tenant's final approval of such stage, including, without
limitation, any changes made to reduce the Cost Quotation pursuant to this Work
Letter, (c) Tenant's failure to furnish any documents required herein or approve
any item or any cost estimates as required herein, (d) Tenant's request for
materials, finishes, or installations other than Landlord's Building Standard
items, (e) Tenant's failure to perform any act or obligation imposed on Tenant
by the Lease or this Work Letter as and when requested thereunder or hereunder,
or (f) any other delay otherwise caused by Tenant, its agents, employees or
contractors which operates to delay Landlord's Substantial Completion of the
Tenant Improvements, as reasonably determined by Landlord.

                             SECTION 5 - TENANT WORK

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                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                   Page 10 of 14
<PAGE>   55

         5.1 FINISH WORK. All finish work and decoration and other work desired
by Tenant and not included within the Improvements as set forth in the approved
Shell Construction Documents or T.I. Construction Documents, including
specifically, without limitation, all computer systems, cabling, telephone
systems, telecommunications systems and other items (the "Tenant Work") shall be
furnished and installed by Tenant at Tenant's sole expense and shall not be
chargeable against the Tenant Improvement Allowance. If any Tenant Work is not
set forth on the approved T.I. Construction Documents, Tenant shall secure
Landlord's prior consent for such Tenant Work in the same manner and following
the same procedures provided for in the Lease. Tenant shall not commence the
construction or installation of any improvements on the Premises, including,
specifically, the Tenant Work, without Landlord's prior written approval (which
shall not be unreasonably withheld) of: (i) Tenant's contractor, (ii) detailed
plans and specifications for the Tenant Work, and (iii) a certificate(s) of
insurance accurately showing that Tenant's contractor maintains insurance
coverage in amounts, types, form and with companies reasonably acceptable to
Landlord. All such certificates or policies shall be endorsed to show Landlord
as an additional insured and insurance shall be maintained by Tenant or Tenant's
contractor at all times during the performance of the Tenant Work.

         5.2 LANDLORD'S OBLIGATIONS. Landlord is under no obligation to
construct or supervise construction of any of the Tenant Work and any inspection
by Landlord shall not be construed as a representation that the Tenant Work is
in compliance with the final plans and specifications therefor or that the
construction will be free from faulty material or workmanship or that the Tenant
Work is in conformance with any building codes or other applicable regulations.
All of the Tenant Work shall be undertaken and performed in strict accordance
with the provisions of the Lease and this Work Letter.

                            SECTION 6 - CHANGE ORDERS

         Tenant may request changes in the Tenant Improvements during
construction only by written instructions to Landlord, or its designated
representative, on a form approved by Landlord. All such changes will be subject
to Landlord's prior written approval, which shall be approved or disapproved by
Landlord in its reasonable discretion, within three (3) Business Days of
receipt. Prior to commencing any change, Landlord will prepare and deliver to
Tenant, for Tenant's approval, a change order (the "Change Order") setting forth
the additional time, if any, needed for such change and the total costs of such
change which will include associated architectural, engineering and construction
contractor's fees. If a Change Order requires additional time to construct, the
Target Commencement Date shall be extended by a similar number of days. Within
two (2) Business Days after delivery to Tenant of the total costs of the Change
Order, Tenant shall deliver notice of approval, together with a cash payment
equal to one hundred percent (100%) of the cost of the Change Order if and to
the extent such cost exceeds the sum of the Tenant Improvement Allowance and the
Tenant Contingency Allowance ("Payment"). If Tenant fails to approve such Change
Order and deliver the Payment within five (5) days after delivery by Landlord,
Tenant will be deemed to have withdrawn the proposed Change Order and Landlord
will not proceed to perform the change. Upon Landlord's receipt of Tenant's
approval and Payment, Contractor will proceed to perform the change.

                     SECTION 7 - RESPONSIBILITY FOR FUNCTION

Tenant will be responsible for the function of all Tenant Improvements whether
or not approved by Landlord or installed by Landlord at Tenant's request.
Landlord's preparation and/or approval of any design or construction documents
will not constitute any representation or warranty as to the adequacy,
efficiency, performance or desirability of the Improvements.

                   SECTION 8 - TENANT AND LANDLORD OBLIGATIONS
                                                                                

4/15/97                                               Landlord Initials: _______
                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                  Page 11 of 14
<PAGE>   56



         8.1 ACCESS AND ENTRY. During Landlord's construction of the Premises,
Landlord agrees to provide reasonable access as described herein to the Premises
to Tenant and its agents, for the purpose of installing Tenant's fixtures,
Tenant Work and furniture, so long as such access does not interfere with the
conduct of Landlord's construction activities or affect Landlord's ability to
diligently bring the Premises to Substantial Completion by the Target
Commencement Date. Landlord acknowledges that access during the construction of
the Tenant Improvements for purpose of performing Tenant Work is important to
Tenant. If Landlord, in its reasonable discretion, determines that the providing
of such access may affect its ability to bring the Premises to Substantial
Completion on the Estimated Lease Term Commencement Date as set forth in this
Lease, Landlord shall have the right to deny or otherwise restrict such access
to Tenant and its agents until Substantial Completion of the Tenant
Improvements. The terms of such access may require that Tenant and Tenant's
agents perform work at times and in the manner designated by Landlord, including
nights, weekends, and holidays. Also, Tenant and its agents may be required to
utilize only certain access areas at certain times, designated by Landlord. With
respect to any approved Tenant Work, Tenant shall adopt a schedule in
conformance with the schedule of Landlord's Contractor and conduct its work in
such a manner as to maintain harmonious labor relations so as not to interfere
unreasonably with or delay the work of Landlord's Contractor. Tenant's
contractors and agents shall be subject to the supervision of Landlord's
construction supervisor.

         8.2 RISK OF LOSS. All materials, work, installations and decorations of
any nature brought upon or installed in the Premises before the Commencement
Date shall be at the risk of the party who brought such materials or items onto
the Premises. Neither Landlord nor any party acting on Landlord's behalf shall
be responsible for any damage or loss or destruction of such items brought to or
installed in the Premises by Tenant prior to such date, except in the event of
Landlord's gross negligence or willful misconduct. As a condition to such early
entry, Landlord may require Tenant to execute a hold harmless agreement, in a
form acceptable to Landlord. Such early occupancy shall be subject to the terms
and provisions of the Lease.

         8.3 CONFORMANCE WITH LAWS. All Tenant Work shall be done in conformity
with applicable codes and regulations of governmental authorities having
jurisdiction over the Project and the Premises and valid building permits and
other necessary authorizations from appropriate governmental agencies when
required, shall be obtained by Tenant for the Tenant Work at Tenant's expense.
Any Tenant Work not acceptable to the applicable governmental authority or not
reasonably satisfactory to Landlord in accordance with the standard in the
preceding sentence (unless previously approved by Landlord), shall be promptly
corrected, replaced, or brought into compliance with such applicable codes and
regulations at Tenant's expense. Notwithstanding any failure by Landlord to
object to any such Tenant Work, Landlord shall have no responsibility therefor.

         8.4 LIENS. Tenant shall keep the Premises and Project free from any
mechanics', materialmen's or other liens arising out of any work performed upon
or materials or furniture, fixtures or improvements delivered to the Premises
including but not limited to any Tenant Work performed, materials furnished or
obligations incurred by or for Tenant or any person or entity claiming by,
through or under Tenant. Landlord shall have the right at all times to post and
keep posted on the Premises any notices which it deems necessary for its
protection from such liens. If any such liens are filed and are not released of
record by payment or posting of a proper bond within ten (10) days after such
filing, Landlord, may, without waiving its rights and remedies based on such
breach by Tenant and without releasing Tenant from any obligations hereunder or
under the Lease, cause such liens to be released by any means it shall deem
proper, including payment of the claim giving rise to such lien in which event
all amounts paid by Landlord shall immediately be due and payable by Tenant.

                       SECTION 9 - TENANT'S REPRESENTATIVE

         Tenant has designated ___________________ as its sole representative
with respect to the matters set forth in this Work

4/15/97                                               Landlord Initials: _______
                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                  Page 12 of 14
<PAGE>   57

Letter, who shall have full authority and responsibility to act on behalf of
Tenant as required in this Work Letter. Tenant may change its representative
under this Work Letter at any time by providing five (5) days prior written
notice to Landlord. All inquiries, requests, instructions, authorizations and
other communications with respect to matters covered by this Work Letter from
Landlord will be made to Tenant's Representative.

                     SECTION 10 - LANDLORD'S REPRESENTATIVE

         Landlord has designated James McCann as its sole representative with
respect to the matters set forth in this Work Letter, who shall have full
authority and responsibility to act on behalf of Landlord as required in this
Work Letter. Landlord may change its representative under this Work Letter at
any time by providing five (5) days prior written notice to Tenant. All
inquiries, requests, instructions, authorizations and other communications with
respect to the matters covered by this Work Letter from Landlord will be made to
Tenant's representative. Tenant will communicate solely with Landlord's
Representative and will not make any inquiries of or requests to, and will not
give any instructions or authorizations to, any other employee or agent of
Landlord, including Landlord's architect, engineers, and contractors or any of
their agents or employees, with regard to matters covered by this Work Letter.

                           SECTION 11 - MISCELLANEOUS

         11.1 SOLE OBLIGATIONS. Except as herein expressly set forth with
respect to the Improvements or in the Lease, Landlord has no agreement with
Tenant and has no obligation to do any work with respect to the Premises. Any
other work in the Premises which may be permitted by Landlord pursuant to the
terms and conditions of the Lease, including any alterations or improvements as
contemplated in the Lease, shall be done at Tenant's sole cost and expense and
in accordance with the terms and conditions of the Lease.

         11.2 APPLICABILITY. This Work Letter shall not be deemed applicable to:
(a) any additional space added to the original Premises at any time, whether by
the exercise of the Right of First Refusal or any options under the Lease or
otherwise, or (b) any portion of the original Premises or any additions thereto
in the event of a renewal or extension of the original Lease Term, whether by
the exercise of any options under the Lease or any amendment or supplement
thereto. The construction of any additions or improvements to the Premises not
contemplated by this Work Letter shall be effected pursuant to a separate work
letter agreement, in the form then being used by Landlord and specifically
addressed to the allocation of costs relating to such construction.

         11.3 AUTHORITY; COUNTERPARTS. Any person signing this Work Letter on
behalf of Tenant warrants and represents that such person has authority to do
so. This Work Letter may be executed in counterparts, each of which shall be
deemed an original, but all of which together constitute one instrument.

         11.4 BINDING ON SUCCESSORS. Subject to the limitations on assignment
and subletting contained in the Lease, this Work Letter shall be binding upon
and inure to the benefit of the parties hereto and their respective heirs, legal
representatives, successors and assigns.

         11.5 LANDLORD'S APPROVAL RIGHTS. Landlord may withhold its approval of
the Space Plan, including any revisions requested by Tenant, the T.I.
Construction Documents, Change Orders or other work requested by Tenant which
require work which: (i)exceeds or affects the structural integrity of the
Project, or any part of the heating, ventilating, air conditioning, plumbing,
mechanical, electrical, communication or other systems of the Project; (ii)is
not approved by the holder of any mortgage or deed of trust encumbering the
Project at the time the work is proposed; (iii)would not be approved by a
prudent owner of property similar to the Project; (iv)violates any agreement
which affects the Project or binds Landlord; (v)Landlord reasonably believes
will increase the cost of operation or maintenance of the common areas within or
any of the systems of the Project; (vi)Landlord reasonably believes will reduce
the market value of the Premises or Project at the end of the Lease Term;
(vii)does not conform

4/15/97                                               Landlord Initials: _______
                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                  Page 13 of 14
<PAGE>   58
to applicable building codes or is not approved by any governmental authority
with jurisdiction over the Premises; (viii)is not a Building Standard item or an
item of equal or higher quality; (ix)in Landlord's determination detrimentally
affects the uniform exterior appearance of the Project; or (x)is reasonably
disapproved by Landlord for any other reason not set forth herein.

         11.6 TIME OF THE ESSENCE. Time is of the essence as to each and every
term and provision of this Work Letter. In all instances where Tenant is
required to approve an item, if no written notice of disapproval is given within
the stated time period at the end of said period the item shall automatically be
deemed approved and the next succeeding time period shall commence. Except as
otherwise provided, all references herein to a "number of days" shall mean and
refer to calendar days.

         11.7 FORCE MAJEURE. If either party cannot perform any of its
obligations due to events beyond such party's control, the time provided for
performing such obligations shall be extended by a period of time equal to the
duration of such events; provided, however, that in no event shall the due date
for the payment of any money be extended.

         11.8 ATTORNEYS' FEES. In any action to enforce or interpret the terms
of this Work Letter, the party prevailing in that action shall be entitled to
recover its reasonable attorneys' fees and costs of suit, both at trial and on
appeal.

         11.9 INCORPORATION. This Work Letter is and shall be incorporated by
reference in the Lease and all of the terms and provisions of the Lease are
incorporated herein for all purposes. Any default by Tenant hereunder also
constitutes a default under the Lease.

         IN WITNESS WHEREOF, the Work Letter has been made and executed as of
the date set forth below.

                           LANDLORD:

Dated:___________________  MARCO PLAZA ENTERPRISES, a
                           California general partnership


                           By:          /s/ Robert Kronick
                              -------------------------------------------------
                           Name:        Robert Kronick
                              -------------------------------------------------
                           Title:       Partner
                              -------------------------------------------------

                           TENANT:

Dated:     4/17/97         TRITEAL CORPORATION, a
                           Delaware corporation

                           By:          /s/ Gregory Jay White
                              -------------------------------------------------
                           Name:        Gregory Jay White
                              -------------------------------------------------
                           Title:       Chief Operating Officer
                              -------------------------------------------------


4/15/97                                               Landlord Initials: _______
                                                        Tenant Initials: _______
                                   EXHIBIT "C"
                                  Page 14 of 14