<PAGE>
                                                                   EXHIBIT 10.11


                            555 TWIN DOLPHIN PLAZA






                       CROSSROUTE SOFTWARE, INCORPORATED
                           a California corporation
<PAGE>

                            BASIC LEASE INFORMATION

                                 OFFICE LEASE

Lease Date:                       March 28, 1997

Landlord:                         SPIEKER PROPERTIES, L.P.
                                  a California limited partnership

Address of Landlord:              555 Twin Dolphin Drive
                                  Suite #110
                                  Redwood City, California 94065

Tenant:                           CROSSROUTE SOFTWARE, INCORPORATED
                                  a California corporation

Address of Tenant:                555 Twin Dolphin Drive
                                  Suite #190
                                  Redwood City, California 94065

Contact:                          Mr. Ken Ross  Telephone:  (415) 596-1300

Premises:                         Approximately 5,255 rentable square feet on
                                  the first floor of the building located at 555
                                  Twin Dolphin Drive, Redwood City, California,
                                  94065, as shown in the attached Exhibit "B"

Scheduled Term Commencement Date:               June 1, 1997

Scheduled Length of Term:                       Sixty (60) Months

Scheduled Term Expiration Date:                 May 31, 2002

Rent:                                           See Addendum #1, Rent, attached
                                                hereto and made a part hereof.

Security Deposit:                               $17,079

Tenant's Proportionate Share:                   2.65%

Permitted Use:                                  General Office

Occupancy Density:                              3.3/1,000 sqft

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

LANDLORD:                               TENANT:

SPIEKER PROPERTIES, L.P.                CROSSROUTE SOFTWARE, INCORPORATED
------------------------                ---------------------------------
a California limited partnership        a California corporation

   By: Spieker Properties, Inc.
       a Maryland corporation

   Its: General Partner


By  /s/ Peter H. Schnugg            By     /s/ Kenneth Ross
    --------------------------          -----------------------------
    Peter H. Schnugg                       Kenneth Ross


Its  Senior Vice President          Its    President
     -------------------------          -----------------------------

Date:                               Date:

      4-7-97                               3/31/97
     -------------------------          -----------------------------
<PAGE>

                                     LEASE

                               TABLE OF CONTENTS

<TABLE>
               <S>                                                             <C>
                   Basic Lease Information
               1.  Premises                                                     3
               2.  Occupancy                                                    3
               3.  Term and Possession                                          3
               4.  Rent                                                         3
               5.  Restrictions On Use                                          4
               6.  Compliance With Laws                                         4
               7.  Alterations                                                  4
               8.  Repairs                                                      4
               9.  Liens                                                        5
               10. Assignment and Subletting                                    5
               11. Insurance and Indemnification                                6
               12. Waiver of Subrogation                                        7
               13. Services and Utilities                                       7
               14. Estoppel Certificate                                         8
               15. Security Deposit                                             8
               16. Substitution                                                 8
               17. Holding Over                                                 8
               18. Subordination                                                8
               19. Rules and Regulations                                        9
               20. Re-entry by Landlord                                         9
               21. Default by Tenant                                            9
               22. Damage by Fire, Etc.                                        11
               23. Eminent Domain                                              11
               24. Sale by Landlord and Tenant's Remedies                      12
               25. Right of Landlord To Perform                                12
               26. Surrender of Premises                                       12
               27. Waiver                                                      12
               28. Notices                                                     13
               29. Rental Adjustments                                          13
               30. Taxes Payable by Tenant                                     15
               31. Successors and Assigns                                      15
               32. Attorneys' Fees                                             15
               33. Light and Air                                               15
               34. Public Transportation Information                           15
               35. Miscellaneous                                               16
               36. Lease Effective Date                                        16

                   Signatures                                                  16
                   Addendum #1 - 3                                             17

                   Exhibit A        Rules and Regulations
                   Exhibit B        Outline of Premises, Suite #180
                   Exhibit D        Form of Tenant Certificate
</TABLE>
<PAGE>

                                     LEASE
                                     -----


THIS LEASE is made this of this 28th day of March, 1997 , between Spieker
                                ----        ------   --           ------
Properties, L.P. a California limited partnership (hereinafter called
-------------------------------------------------
"Landlord") and CrossRoute Software Incorporated, a California corporation
                ----------------------------------------------------------
hereinafter "Tenant").

PREMISES

1.   Landlord leases to Tenant and Tenant leases from Landlord those premises
     (hereinafter called "Premises") outlined in red on Exhibit B attached
     hereto and made a part hereof, specified in the Basic Lease Information
     attached hereto. The Premises may be all or part of the building (the
     "Building") or of the project (the "Project") which may consist of more
     than one building.

OCCUPANCY

2.   Tenant shall use the Premises for the Permitted Use and for no other use or
     purpose without the prior written consent of Landlord. No increase in
     occupant density of the Leased Premises shall be made which shall add to
     the burden of such use of the Building as determined by Landlord without
     the prior written consent of Landlord.

TERM AND POSSESSION

3.   (a)  The parties project that the term shall commence on the Scheduled
          Term Commencement Date and, except as otherwise provided herein or in
          any exhibit or addendum hereto, shall continue in full force until the
          Term Expiration Date. If the Premises are not delivered by Landlord by
          the Scheduled Term Commencement Date for any reason, Landlord shall
          not be liable to Tenant for any loss or damage resulting from such
          delay. The Term Commencement Date shall be the first day of the
          calendar month next following the earlier of (i) the day when the
          Premises are substantially complete, or (ii) the date on which Tenant
          takes possession of, or commences the operation of its business in
          some or all of the Premises. If substantial completion occurs prior to
          the Scheduled Term Commencement Date, Tenant shall take occupancy.
          Landlord shall provide Tenant as much notice as circumstances allow of
          the date when Landlord expects to achieve substantial completion,
          based upon the progress of work. Should the Term Commencement Date be
          a date other than the Scheduled Term Commencement Date, either
          Landlord or Tenant, at the request of the other shall execute a
          declaration specifying the Term Commencement Date and the rent
          commencement date which shall be binding upon the parties as to the
          matters therein stated. Tenant's obligation to pay Rent and its other
          obligations for payment under this Lease shall commence upon the
          earlier of (i) the day when the Premises are substantially complete,
          or (ii) the date on which Tenant takes possession of, or commences the
          operation of its business in some or all of the Premises.

     (c)  The Premises shall be substantially complete and possession shall be
          delivered when (i) installation of Building Standard Work (which shall
          not include installation of telephone and other communication
          facilities or equipment, finish work and decoration to be performed by
          Tenant) has occurred, (ii) Tenant has direct access from the street to
          the elevator lobby on the floor where the Premises are located (iii)
          Landlord is in a position to furnish Building services to the
          Premises, and (iv) Landlord's architect shall certify substantial
          completion with respect to the premises, whether or not substantial
          completion of the Building itself shall have occurred. Substantial
          completion shall be deemed to have occurred notwithstanding a
          requirement to complete "punchlist" or similar corrective work.

RENT

4.   Tenant shall pay to Landlord throughout the Term Rent as specified in the
     Basic Lease Information, payable in equal monthly installments in advance
     on the first day of each calendar month during every year of the Term in
     lawful money of the United States, without deduction or offset whatsoever,
     to Landlord at the address specified in the Basic Lease Information or to
     such other firm or to such other place as Landlord may from time to time
     designate in writing by notice given as herein provided. Rent for the first
     month of the Term shall be paid by Tenant upon execution of this Lease. If
     the obligation for payment of Rent commences on other than the first day of
     a month as provided in paragraph 3(a), then Rent provided for such partial
     month shall be prorated and the prorated installment shall be paid on the
     first day of the calendar month next succeeding the Term Commencement Date.
     If the Term terminates on other than the last day of a calendar month, then
     the Rent provided for such partial month shall be prorated and the prorated
     installment shall be paid on the first day of the calendar month next
     preceding the date of termination.

                                       3
<PAGE>

RESTRICTIONS ON USE

5.   Tenant shall not do or permit anything to be done in or about the Premises
     which will in any way obstruct or interfere with the rights of other
     tenants or occupants of the Building or injure or annoy them, nor use or
     allow the Premises to be used for any improper, immoral, unlawful or
     objectionable purposes, nor shall Tenant cause or maintain or permit any
     nuisance in, on or about the Premises. Tenant shall not commit or suffer
     the commission of any waste in, on or about the Premises.

COMPLIANCE WITH LAWS

6.   Tenant shall not use the Premises or permit anything to be done in or about
     the Premises which will in any way conflict with any law, statute,
     ordinance or governmental rule or regulation now in force or which may
     hereafter be enacted or promulgated. Tenant shall not do or permit anything
     to be done on or about the Premises or bring or keep anything therein which
     will in any way increase the rate of any insurance upon the Building or any
     of its contents or cause a cancellation or said insurance or otherwise
     affect said insurance in any manner, and Tenant shall at its sole cost and
     expense promptly comply with all laws, statutes, ordinances and
     governmental rules, regulations or requirements now in force or which may
     hereafter be in force and with the requirements of any board of fire
     underwriters or other similar body now or hereafter constituted relating to
     or affecting the condition, use or occupancy of the Premises, excluding
     structural changes not related to or affected by alterations or
     improvements made by or for Tenant or Tenant's acts. The judgement of any
     court of competent jurisdiction or the admission of Tenant in any actions
     against Tenant, whether Landlord be a party thereto or not, that Tenant has
     so violated any such law, statute, ordinance, rule, regulation or
     requirement, shall be conclusive of such violation as between Landlord and
     Tenant.

ALTERATIONS

7.   Tenant shall not make or suffer to be made any alterations, additions or
     improvements in, on or to the Premises or any part thereof without the
     prior written consent of Landlord; and any such alterations, additions or
     improvements in, on or to said Premises, except for Tenant's movable
     furniture and equipment, shall immediately become Landlord's property and,
     at the end of the Term, shall remain on the Premises without compensation
     to Tenant. In the event Landlord consents to the making of any such
     alteration, addition or improvement by Tenant, the same shall be made by
     Tenant, at Tenant's sole cost and expense, in accordance with plans and
     specifications approved by Landlord, and any contractor or person selected
     by Tenant to make the same must first be approved in writing by Landlord.
     Notwithstanding the foregoing, Tenant shall be permitted to make non-
     structural alterations or additions, the costs of which do not exceed
     $1,000 per work of improvement, without Landlord's written approval.

     Notwithstanding the foregoing, Landlord, shall agree to allow Tenant to
     contract with outside licensed contractors for installation of additional
     approved tenant work for Tenant's account, subject to review and approval
     of all work and contractors by Landlord. Landlord shall have the right to
     collect from Tenant a supervision fee equal to 15% of the total direct
     costs associated with Tenant's improvements to the Premises, per the terms
     of Paragraph 7. Upon the expiration or sooner termination of the Term,
     Tenant shall upon demand by Landlord, at Tenant's sole cost and expense,
     with all due diligence remove all those alterations, additions or
     improvements made by or for the account of Tenant, designated by Landlord
     to be removed and Tenant shall with all due diligence, at its sole cost and
     expense, repair and restore the Premises to their original condition. At
     Landlord's election and notwithstanding the foregoing, however, Tenant
     shall pay to Landlord the cost of removing any such alterations, additions
     or improvements and restoring the Premises to their original condition such
     cost to include a reasonable charge for Landlord's overhead and profit as
     provided above, and such amount may be deducted from the Security Deposit
     or any other sums or amounts held by Landlord under this Lease.

REPAIRS

8.   By taking possession of the Premises, Tenant accepts the Premises as being
     in the condition in which Landlord is obligated to deliver them and
     otherwise in good order, condition and repair. At all times during the Term
     Tenant shall, at Tenant's sole cost and expense, keep the Premises and
     every part thereof in good order, condition and repair, excepting damage
     thereto by fire, earthquake, act of God or other elements. Tenant waives
     all right it may have under Section 1942 of the Civil Code of the State of
     California and any similar law, statues or ordinance now or hereafter in
     effect (to the full extent that such waiver may lawfully be given)
     authorizing or purporting to authorize Tenant to make repairs to or for the
     account of Landlord. Tenant shall upon the expiration or sooner termination
     of the Term hereof, unless Landlord demands otherwise pursuant to paragraph
     7 hereof, surrender to Landlord the Premises and all repairs, changes,
     alterations, additions and improvements thereto in the same condition as
     when received or when first installed, damage by fire, earthquake, act of
     God or the elements excepted, Landlord has no obligation to alter, remodel,
     improve, repair, decorate or paint the Premises or any part thereof, except
     as specified in the Office Lease Improvement Agreement and no
     representations respecting the condition of the Premises or the Building
     have been made by Landlord to Tenant, except as specifically set forth
     therein or in the Office Lease Improvement Agreement.

                                       4
<PAGE>

LIENS

9.   Tenant shall keep the Premises free from liens arising out of or related to
     work performed, materials or supplies furnished or obligations incurred by
     Tenant or in connection with work made, suffered or done by Tenant in
     Premises or Building. In the event that Tenant shall not, within ten (10)
     days following the imposition of any such lien, cause the same to be
     released of record by payment or posting of a proper bond, Landlord shall
     have, in addition to all other remedies provided herein and by law, the
     right, but no obligation, to cause the same to be released by such means as
     it shall deem proper, including payment of the claim giving rise to such
     lien. Landlord shall have the right at all times to post and keep posted on
     the Premises any notices permitted or required by law, or which Landlord
     shall deem proper, for the protection of Landlord, the Premises, the
     Building and any other party having an interest therein, from mechanics'
     and materialmen's liens, and Tenant shall give Landlord not less than ten
     (10) business days prior written notice of the commencement of any work in
     the Building or Premises which could lawfully give rise to a claim for
     mechanics' or materialmen's liens.

ASSIGNMENT AND SUBLETTING

10.  Tenant shall not sell, assign, encumber or otherwise transfer this Lease or
     any interest therein (by operation of law or otherwise), sublet the
     Premises or any part thereof or suffer any other person to occupy or use
     the Premises or any portion thereof, nor shall Tenant permit any lien to be
     placed on Tenant's interest under this Lease by operation of law except in
     accordance with the provisions of this paragraph 10. For purposes hereof,
     sales, transfers or assignments of (i) a controlling interest in the stock
     of Tenant, if Tenant is a corporation, or of (ii) the general partnership
     interests sufficient to control management decisions if Tenant is a
     partnership or of (iii) the majority or controlling underlying beneficial
     interest, if Tenant is any other form of business entity, shall constitute
     an assignment subject to the terms of this paragraph 10.

     (a)  In the event that Tenant should desire to sublet the Premises or any
          part thereof, Tenant shall provide Landlord with written notice of
          such desire at least ninety (90) days in advance of the date on which
          Tenant desires to make such sublease. Landlord shall then have a
          period of thirty (30) days following receipt of such notice within
          which to notify Tenant in writing that Landlord elects either (i) to
          terminate this Lease as to the space so affected as of the date so
          specified by Tenant, in which event Tenant shall be relieved of all
          further obligations hereunder as to such space from and after that
          date, or (ii) to permit Tenant to sublet such space, subject, however,
          to the prior written approval of the proposed Sublessee by Landlord
          which said consent shall not be unreasonably withheld. If Landlord
          should fail to notify Tenant in writing of its election within said
          thirty (30) day period, Landlord shall be deemed to have waived option
          (i) above, but written approval of the proposed Sublessee shall still
          be required. Refusal by Landlord to approve a proposed Sublessee shall
          not constitute a termination of this Lease. In exercising its right of
          consent to a Sublessee it shall be reasonable for Landlord to withhold
          consent to any Sublessee who (aa) does not agree to assume the
          obligations of the Lease with respect to the space to be so sublet,
          (bb) does not agree to utilize the space so sublet for the Permitted
          Use, (cc) is of unsound financial condition as determined by Landlord,
          or (dd) will, in Landlord's opinion increase the occupant density in
          the Leased Premises. If Tenant proposes to sublease less than all of
          the Premises, election by Landlord of termination of this Lease with
          respect to space to be so sublet shall leave this Lease in full force
          and effect with respect to the remainder of the space, the Rent and
          Tenant's Proportionate Share of Operating Expenses and taxes shall be
          adjusted on a pro rata basis to reflect the reduction in Net Rentable
          Area of the Premises as retained by Tenant. This Lease as so amended
          shall continue thereafter in full force and effect and references
          herein to the Premises shall mean that portion thereof as to which the
          Lease has not been terminated.

     (b)  Tenant shall not enter into any other transaction subject to this
          paragraph 10 without Landlord's prior written consent which said
          consent shall not be unreasonably withheld. It shall be reasonable for
          Landlord to withhold consent to any proposed transaction described in
          this paragraph 10 on any of the grounds specified in paragraph 10 (a)
          with respect to sublessee's or any other reasonable grounds.

     (c)  Any rent or other consideration realized by Tenant under any such
          sublease or assignment to which Landlord has consented hereunder, in
          excess of the Rent payable hereunder, after amortization or the
          reasonable cost of the improvements over the remainder of the Term for
          which Tenant has paid and reasonable subletting and assignment costs,
          shall be divided and paid ninety percent (90%) to Landlord and ten
          percent (10%) to Tenant.

     (d)  Any subletting hereunder by Tenant shall not result in Tenant being
          released or discharged from any liability under this lease. Any
          purported assignment, subletting or other transaction to which
          paragraph 10 applies, which occurs contrary to the provisions hereof,
          shall be void. Landlord's consent to any assignment, subletting or
          other transaction to which this paragraph 10 applies shall not release
          Tenant from any of Tenant's obligations hereunder or constitute a
          consent with respect to any subsequent transaction to which this
          paragraph applies.

                                       5
<PAGE>

INSURANCE AND INDEMNIFICATION

11.  (a)  Landlord shall not be liable to Tenant and Tenant hereby waives all
          claims against Landlord for any injury or damage to any person or
          property in or about the Premises by or from any cause whatsoever
          (other than Landlord's gross negligence or willful misconduct) and,
          without limiting the generality of the foregoing, whether caused by
          water leakage of any character from the roof, walls, basement or other
          portion of the Premises or the Building, or caused by gas, fire, oil
          or electricity in, on or about the Premises or the Building.

     (b)  Tenant shall hold Landlord harmless from and defend Landlord against
          any and all claims or liability for any injury or damage to any person
          or properly whatsoever; (i) occurring in, on, or about the Premises or
          any part thereof, or (ii) occurring in, on or about any facilities
          (including, without prejudice to the generality of the term
          "facilities", elevators, stairways, lobbies, health clubs, passageways
          or hallways), the use of which Tenant may have in conjunction with
          other tenants of the Building, when such injury or damage shall be
          caused in part or in whole by the act, neglect, fault of or omission
          of any duty with respect to the same by Tenant, its agents, servants,
          employees or invitees. Tenant shall further indemnify and save
          Landlord harmless against and from any and all claims by or on behalf
          of any person, firm or corporation arising from the conduct or
          management of any work or thing whatsoever done by Tenant in or about
          or from transactions of Tenant concerning the Premises, and will
          further indemnify and save Landlord harmless against and from any and
          all claims arising from any breach or default on the part of Tenant in
          the performance of any covenant or agreement on the part of Tenant to
          be performed pursuant to the terms of this Lease or arising from any
          act or negligence of Tenant, or any of its agents, contractors,
          servants, employees or licensees, and from and against all costs,
          counsel fees, expenses and liabilities incurred in connection with any
          such claim or action or proceeding brought thereon. In case any action
          or proceeding is brought against Landlord by reason of any claims or
          liability within the limits of the foregoing indemnity, Tenant shall
          defend such action or proceeding at Tenant's sole expense by counsel
          reasonably satisfactory to Landlord.

     (c)  Landlord shall hold Tenant harmless from and defend Tenant against any
          and all claims or liability for any injury or damage to any person or
          property occurring in or about any facilities (including, without
          prejudice to the generality of the term "facilities", elevators,
          stairways, passageways or hallways), the use of which Tenant may have
          in conjunction with other tenants of the building, when such injury or
          damage shall be caused in whole or in part by the act, neglect, fault
          of or omission of any duty with respect to the same by Landlord, its
          agents, servants, employees or invitees. Landlord shall further
          indemnify and save Tenant harmless against and from any and all claims
          by or on behalf of any person, firm or corporation arising from the
          conduct or management of any work or thing whatsoever done by Landlord
          in or about, or from transactions of Landlord concerning, the Premises
          where such work is not being done for the account of Tenant; and
          Landlord will further indemnify and save Tenant harmless against and
          from any and all claims arising from any breach or default on the part
          of Landlord in the performance of any covenant or agreement on the
          part of Landlord to be performed pursuant to the terms of this Lease
          or arising from any act or negligence of Landlord, or any of its
          agents, contractors, servants, employees or licensees, and from and
          against all costs, counsel fees, expenses and liabilities incurred in
          connection with any such claims or action or proceeding brought
          thereon. In case any action or proceeding is brought against Tenant by
          reason of any claims or liability within the limits of the foregoing
          indemnity, Landlord shall defend such action or proceeding at
          Landlord's sole expense by counsel reasonably satisfactory to Tenant.

     (d)  The provisions of paragraph 11 (b) and 11 (c) shall survive the
          expiration or termination of this Lease with respect to any claims or
          liability occurring prior to such expiration or termination.

     (e)  Tenant shall purchase at its own expense and keep in force during the
          Term of this Lease a policy or policies of workers' compensation and
          comprehensive liability insurance, including personal injury and
          property damage, in the amount of Five Hundred Thousand Dollars
          ($500,000.00) for property damage and Two Million Dollars
          ($2,000,000.00) per occurrence for personal injuries or deaths of
          persons occurring in or about the Premises. The foregoing limits shall
          be increased in proportion to increases during the Term in the United
          States Department of Labor, Bureau of Labor Statistics, Cost of Living
          Index, All Urban consumers (1967=100) for the region in which the
          Leased Premises are located. Said policies shall: (i) name Landlord
          and any party holding an interest to which this Lease may be
          subordinated under paragraph 18 hereof, as additional insureds, and
          insure Landlord's contingent liability under this Lease; (ii) be
          issued by an insurance company acceptable to Landlord and licensed to
          do business in the State of California; and (iii) provide that said
          insurance shall not be cancelled unless ten (10) days prior written
          notice shall have been given to Landlord. Said policy or policies or
          certificates thereof shall be delivered to Landlord by Tenant upon
          commencement of the term of this Lease and upon each renewal of said
          insurance.

                                       6
<PAGE>

WAIVER OF SUBROGATION

12. To the extent permitted by law and without affecting the coverage provided
    by insurance required to be maintained hereunder Landlord and Tenant each
    waive any right to recover against the other (i) damages for injury, to or
    death of persons, (ii) damages to property (iii) damage to the Premises or
    any part thereof, (ix,) damage to the Braiding or any part thereof, or (v)
    claims arising by reason of the foregoing, but only to the extent that any
    of the foregoing damages and/or claims referred to above are covered (and
    only to the extent of such coverage) by insurance actually carried by either
    Landlord or Tenant. This provision is intended to waive fully, and for the
    benefit of each party, any rights and/or claims which might give rise to a
    right of subrogation on any insurance carrier. The coverage obtained by each
    party pursuant to this Lease shall include, but without limitation, a waiver
    of subrogation by the carrier which conforms to the provisions of this
    paragraph.

SERVICES AND UTILITIES

13. (a)   Landlord shall maintain the public and common areas of the Building,
          including lobbies, stairs, elevators, corridors and restrooms, the
          windows in the Building, the mechanical, plumbing and electrical
          equipment serving the Building, and the structure itself, in
          reasonably good order and condition except for damage occasioned by
          the act of Tenant, which damage shall be repaired by Landlord at
          Tenant's expense.

    (b)   Provided Tenant shall not be in default hereunder, and subject to the
          provisions elsewhere herein contained and to the rules and regulations
          of the Building, Landlord shall furnish to the Premises during
          ordinary business hours of generally recognized business days to be
          determined by Landlord (but exclusive, in any event, of Saturdays,
          Sundays and legal holidays), water and electricity suitable for the
          Permitted Uses of the Premises, heat and air conditioning required in
          Landlord's judgement for the comfortable use and occupation of the
          Premises for the Permitted Uses, janitorial services during the times
          and in the manner that such services are, in Landlord's judgement,
          customarily furnished in comparable buildings in the immediate market
          area, and elevator service which shall mean service either by
          nonattended automatic elevators or elevators with attendants, or both,
          at the option of Landlord. Landlord shall have no obligation to
          provide additional or after-hours heating or air-conditioning, but if
          Landlord elects to provide such services at Tenant's request, Tenant
          shall pay to Landlord a reasonable charge for such services as
          determined by Landlord. Tenant agrees to keep and cause to be kept
          closed all window coverings when necessary because of the sun's
          position, and Tenant agrees at all times to cooperate fully with
          Landlord and to abide by all the regulations and requirements which
          Landlord may prescribe for the proper functioning and protection of
          heating, ventilating and air-conditioning systems. Wherever heat-
          generating machines, excess lighting or equipment are used in the
          Premises which affect the temperature otherwise maintained by the air
          conditioning system, Landlord reserves the right to install
          supplementary air-conditioning units in the Premises, and the cost
          thereof, including the cost of installation and the cost of operating
          and maintenance thereof, shall be paid by Tenant to Landlord upon
          demand by Landlord.

    (c)   Tenant shall not without written consent of Landlord use any apparatus
          or device in the Premises, including without limitation, electronic
          data processing machines, punch card machines and machines using
          excess lighting or using current in excess of that which is determined
          by Landlord as reasonable and normal for the Permitted Use or which
          will in any way increase the amount of electricity or water usually
          furnished or supplied for the Permitted uses of the Premises; not
          connect with electric current, except through existing electrical
          outlets in the Premises or water pipes, any apparatus or device for
          the purposes of using electrical current or water. If Tenant shall
          require water or electrical current or any other resource in excess of
          that usually furnished or supplied for the Permitted Use of the
          Premises, Tenant shall first procure the consent of Landlord which
          Landlord may refuse, to the use thereof, and Landlord may cause a
          special meter to be installed in the Premises so as to measure the
          amount of water, electrical current or other resource consumed for any
          such other use. Tenant shall pay directly to Landlord as an addition
          to and separate from payment of Basic Operating Costs the cost of all
          such energy, utility service and meters (and of installation,
          maintenance and repair thereof). Landlord may add to the metered
          charge a recovery of additional expense incurred in keeping account of
          the water, electrical current or other resource so consumed. Landlord
          shall not be liable for any damages directly or indirectly resulting
          from, nor shall the Rent herein reserved be abated by reason of (i)
          the installation, use or interruption of use of any equipment in
          connection with the furnishing of any of the foregoing utilities and
          services, (ii) failure to furnish or delay in furnishing any such
          utilities or services when such failure or delay is caused by acts of
          God or the elements, labor disturbances of any character, any other
          accidents or other conditions beyond the reasonable control of
          Landlord, or by making of repairs or improvements to the Premises or
          to the Building, or (iii) the limitation, curtailment, rationing or
          restriction on use of water, electricity, gas or any other form of
          energy or any other service or utility whatsoever serving the Premises
          or the Building. Landlord shall be entitled to cooperate voluntarily
          and in a reasonable manner with the efforts of national, state or
          local government agencies or utility suppliers in reducing energy or
          other resource consumption. The obligation to make services available
          hereunder shall be subject to the limitations of any such voluntary,
          reasonable program.

    (d)   Any sums payable under this paragraph 13 shall constitute Additional
          Rent hereunder.

                                       7
<PAGE>

ESTOPPEL CERTIFICATE

14.  Within ten (10) days following any written request which Landlord may make
     from time to time, Tenant shall execute and deliver to Landlord a
     certificate substantially in the form attached hereto as Exhibit D and made
     a part hereof indicating thereon any exceptions thereto which may exist at
     /hat time. Failure by Tenant to execute and deliver such certificate shall
     constitute an acceptance of the Premises and acknowledgment by Tenant that
     the statements included in Exhibit D are true and correct without
     exception. Landlord and Tenant intend that any statement delivered pursuant
     to this paragraph may be relied upon by any mortgagee, beneficiary,
     purchaser or prospective purchaser of the Building or any interest therein.
     Landlord shall have the right to substitute for the attached Exhibit D a
     certificate in form required by Landlord's mortgagee or provider of
     financing.

SECURITY DEPOSIT

15.  Concurrently with execution hereof, Tenant has paid to Landlord the
     Security Deposit in the amount stated on the Basic Lease Information Sheet
     as security for the full and faithful performance of Tenant's obligations
     under this Lease. Upon expiration of the Term or earlier termination
     hereof, the Security Deposit shall be returned to Tenant, reduced by such
     amounts as may be required by Landlord to remedy defaults on the part of
     Tenant in the payment of Rent, to repair damages to the Premises caused by
     Tenant and to clean the Premises. Landlord shall hold the Security Deposit
     for the foregoing purposes in accordance with the provisions of all
     applicable law.

SUBSTITUTION

16.  At any time after execution of this Lease, Landlord may substitute for the
     Premises other premises in the Building (the "New Premises") upon not less
     than ninety (90) days prior written notice, in which event the new Premises
     shall be deemed to be the Premises for all purposes hereunder; provided,
     however, that:

     (a)  The Net Rentable Area in the Premises is less than five thousand
          (5,000) square feet;

     (b)  The New Premises shall be similar in area and in appropriateness for
          Tenant's purposes;

     (c)  Any such substitution is effected for the purpose of accommodating a
          tenant who will occupy all or a substantial portion of the Net
          Rentable Area of the floor on which the Premises are located; and

     (d)  If Tenant is occupying the Premises at the time of such substitution,
          Landlord shall pay the expense of moving Tenant, its property and
          equipment to the New Premises and shall, at its sole cost, improve the
          New Premises with improvements substantially similar to those Landlord
          has committed to provide or has provided in the Premises.

HOLDING OVER

17.  If Tenant shall retain possession of the Premises or any part thereof
     without Landlord's consent following the expiration of the Term or sooner
     termination of this Lease for any reason, then Tenant shall pay to Landlord
     for each day of such retention triple the amount of the daily rental for
     the last period prior to the date of such expiration or termination. Tenant
     shall also indemnify and hold Landlord harmless from any loss or liability
     resulting from delay by Tenant in surrendering the Premises, including,
     without limitation, any claims made by any succeeding Tenant founded on
     such delay. Alternatively, if Landlord gives notice to Tenant of Landlord's
     election thereof, such holding over shall constitute renewal of this Lease
     for a period from month to month, or for one year, whichever shall be
     specified in such notice. Acceptance of Rent by Landlord following
     expiration or termination shall not constitute a renewal of this Lease, and
     nothing contained in this paragraph shall waive Landlord's right to reentry
     or any other right. Unless Landlord exercises the option hereby given to
     it, Tenant shall be only a Tenant at sufferance, whether or not Landlord
     accepts any Rent from Tenant while Tenant is holding over without
     Landlord's written consent.

SUBORDINATION

18.  Without the necessity of any additional document being executed by Tenant
     for the purpose of effecting a subordination, this Lease shall be subject
     and subordinate at all times to: (a) all ground leases or underlying leases
     which may now exist or hereafter be executed affecting the Building or the
     land upon which the Building is situated or both, and (b) the lien of any
     mortgage or deed of trust which may now exist or hereafter be executed in
     any amount for which said Building, land, ground leases or underlying
     leases, or Landlord's interest or estate in any of said items, is specified
     as security. Notwithstanding the foregoing, Landlord shall have the right
     to subordinate or cause to be subordinated any such ground leases or
     underlying leases or any such liens to this Lease. In the event that any
     ground leases or underlying lease terminates for any reason or any mortgage
     or deed of trust is foreclosed or a conveyance in lieu of foreclosure is
     made for any reason, Tenant shall, notwithstanding any subordination,
     attorn to and become the Tenant of the successor in interest to Landlord at
     the option of such

                                       8
<PAGE>

     successor in interest. Tenant shall execute and deliver, upon demand by
     Landlord and in the form requested by Landlord, any additional documents
     evidencing the priority or subordination of this Lease with respect to any
     such ground leases or underlying leases or the lien of any such mortgage or
     deed of trust. Tenant hereby irrevocably appoints Landlord as attorney-in-
     fact for Tenant to execute, deliver and record any such documents in the
     name and on behalf of Tenant At the request of Landlord, Tenant shall
     provide to Landlord its current financial  statement or other information
     disclosing financial worth which Landlord shall use solely for purposes of
     this lease and in connection with the ownership, management and disposition
     of the property subject hereto.

RULES AND REGULATIONS

19.  Tenant shall faithfully observe and comply with the rules and regulations
     printed on or annexed to this Lease and all reasonable modifications
     thereof and additions thereto from time to time put into effect by
     Landlord. Landlord shall not be responsible to Tenant for the non-
     compliance by any other Tenant or occupant of the Building with any of the
     rules and regulations.

RE-ENTRY BY LANDLORD

20.  Landlord reserves and shall at all times have the right to re-enter the
     Premises to inspect the same, to provide any services to be provided by
     Landlord to Tenant hereunder, to show the Premises to prospective
     purchasers, mortgagees or tenants, to post notices of nonresponsibility and
     to alter, improve or repair the Premises and any portion of the Building,
     Without abatement of Rent, and may for that purpose erect, use and maintain
     scaffolding, pipes, conduits and other necessary structures in and through
     the Premises where reasonably required by the character of the work to be
     performed; provided that entrance to the Premises shall not be blocked
     thereby, and further provided that the business of Tenant shall not be
     interfered with unreasonably. Tenant waives any claim for damages for any
     injury or inconveniences to or interference with Tenant's business, any
     loss of occupancy or quiet enjoyment of the Premises, and any other loss
     occasioned thereby. Landlord shall at all times have and retain a key with
     which to unlock all of the doors in, upon and about the Premises, excluding
     Tenant's vaults and safes or special security areas (designated in
     advance), and Landlord shall have the right to use any and all means which
     Landlord may deem necessary or proper to open said doors in an emergency,
     in order to obtain entry to any portion of the Premises, and any entry to
     the Premises or portions thereof obtained by Landlord by any of said means,
     or otherwise, shall not be construed to be a forcible or unlawful entry
     into, or a detainer of, the Premises, or any eviction, actual or
     constructive, of Tenant from the premises or any portions thereof. Landlord
     shall also have the right at any time, without the same constituting an
     actual or constructive eviction and without incurring any liability to
     Tenant therefore, to change the arrangement and/or location of entrances or
     passageway, doors and doorways, and corridors, elevators, stairs, toilets
     or other public parts of the Building, and to change the name, number or
     designation by which the Building is commonly known.

DEFAULT BY TENANT

21.  (a)  Events of Default:

          The occurrence of any of the following shall constitute an event of
          default on the part of Tenant:

          (1)  Abandonment. Vacation or Abandonment of the Premises for a
               continuous period in excess of five (5) business days. Tenant
               waives any right to notice Tenant may have under Section 1951.3
               of the Civil Code of the State of California, the terms of this
               subsection (a) being deemed such notice to Tenant as required by
               said Section 1951.3;

          (2)  Nonpayment of Rent. Failure to pay any installment of Rent due
               and payable hereunder (or failure to pay any other amount
               required to be paid hereunder, all such obligations to be
               construed as the equivalent of obligations for payment of Rent)
               upon the date when said payment is due, such failure continuing
               without cure by payment of the delinquent Rent and late charge
               for a period of five (5) business days after written notice and
               demand; provided, however, that except as expressly otherwise
               provided herein, Landlord shall not be required to provide such
               notice more than twice during the Term, the third such non-
               payment constituting default for all purposes hereof without
               requirement of notice. For purposes of subparagraph 21(e), such
               failure shall constitute a default without requirement of notice.

               The due dates for payment of installments of rent provided for
               herein shall be absolute and the existence of a cure period or
               notice period shall not be deemed to extend said date for
               purposes of determining Tenant's compliance with its obligations
               hereunder.

          (3)  Other Obligations. Failure to perform any obligations, agreement
               or covenant under this Lease other than those matters specified
               in subparagraphs (1) and (2) of this subparagraph (a), such
               failure continuing for fifteen (15) business days after written
               notice of such failure (or such longer period as Landlord
               determines to be necessary to remedy such default, provided that
               Tenant shall continuously and diligently pursue such remedy at
               all times until such default is cured);

                                       9
<PAGE>

          (4)  General Assignment. A general assignment by Tenant for the
               Benefit of creditors;

          (5)  Bankruptcy. The filing of any voluntary petition in bankruptcy by
               Tenant, or the filing of an involuntary petition by Tenant's
               creditors, which involuntary petition remains undischarged for a
               period of thirty (30) days. In the event that under applicable
               law the trustee in bankruptcy or Tenant has the right, to affirm
               this Lease and continue to perform the obligations of Tenant
               hereunder, such trustee or Tenant shall, in such time period as
               may be permitted by the bankruptcy court having jurisdiction,
               cure all defaults of Tenant hereunder outstanding as of the day
               of the affirmance of this Lease and provide to Landlord such
               adequate assurances as may be necessary to ensure Landlord of the
               continued performance of Tenant's obligations under this Lease:

          (6)  Receivership. The employment of a receiver to take possession of
               substantially all of Tenant's assets or the Premises, if such
               receivership remains undissolved for a period of ten (10)
               business days after creation thereof;

          (7)  Attachment. The attachment, execution or other judicial seizure
               of all or substantially all of Tenant's assets or the Premises,
               if such attachment or other seizure remains undismissed or
               undischarged for a period of ten (10) business days after the
               levy thereof;

          (8)  Insolvency. The admission by Tenant in writing of its inability
               to pay its debts as they become due, the filing by Tenant of a
               petition seeking any reorganization, arrangement, composition,
               readjustment, liquidation, dissolution or similar relief under
               any present or future statute, law or regulation, the filing by
               Tenant of an answer admitting or failing timely to contest a
               material allegation of a petition filed against Tenant in any
               such proceeding or, if within thirty (30) days after the
               commencement of any proceeding against Tenant seeking any
               reorganization or arrangement, composition, readjustment,
               liquidation, dissolution or similar relief under any present or
               future statute, law or regulation, such proceeding shall not have
               been dismissed.

     (b)  Remedies Upon Default.

          (1)  Rent. All failures to pay any monetary obligation to be paid by
               Tenant under this Lease shall be construed as obligations for
               payment of Rent.

          (2)  Termination. In the event of the occurrence of any event of
               default, Landlord shall have the right, with or without notice or
               demand, immediately to terminate this Lease, and at any time
               thereafter recover possession of the Premises or any part thereof
               and expel and remove therefrom Tenant and any other person
               occupying the same, by any lawful means, and again repossess and
               enjoy the Premises without prejudice to any of the remedies that
               Landlord may have under this Lease, or at law or equity by reason
               of Tenant's default or of such termination.

          (3)  Continuation After Default. Even though Tenant has breached this
               Lease and/or abandoned the Premises, this Lease shall continue in
               effect for so long as Landlord does not terminate Tenant's right
               to possession under paragraph 21 (b) (2) hereof, and Landlord may
               enforce all its right and remedies under this Lease, including
               rout without limitation) the right to recover Rent as it becomes
               due; and Landlord, without terminating this Lease, may exercise
               all of the rights and remedies of a Landlord under Section 1951.4
               of the Civil Code of the State of California or any successor
               code section. Acts of maintenance, preservation or efforts to
               lease the premises or the appointment of receiver upon
               application of Landlord to protect Landlord's interests under
               this Lease shall not constitute an election to terminate Tenant's
               right to possession.

     (c)   Damages Upon Termination.

               Should Landlord terminate this Lease pursuant to the provisions
               of paragraph 21(b)(2) hereof, Landlord shall have all the rights
               and remedies of a landlord provided by Section 1951.2 of the
               Civil Code of the State of California, or successor code section.
               Upon such termination, in addition to any other rights and
               remedies to which Landlord may be entitled under applicable law,
               Landlord shall be entitled to recover from Tenant: (i) the worth
               at the time of award of the unpaid Rent and other amounts which
               had been earned at the time of termination; (ii) the worth at the
               time of award of the amount by which the unpaid Rent which would
               have been earned after termination until the time of award
               exceeds the amount of such Rent loss that the Tenant proves could
               have been reasonably avoided; (iii) the worth at the time of
               award of the amount by which the unpaid Rent for the balance of
               the Term after the time of award exceeds the amount of such Rent
               loss that the Tenant proves could be 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. The "worth at the
               time of award" of the amounts referred to in (i) and (ii) shall
               be computed with interest at the lesser of eighteen percent (18%)
               per annum or the maximum rate allowed by law. The "worth at the
               time of award" of the amount referred to in (iii) shall be
               computed by reference to competent appraisal evidence or the
               formula prescribed by and using the lowest discount rate
               permitted under applicable law.

                                      10
<PAGE>

     (d)  Computation of Rent For Purposes of Default.

          For purposes of computing unpaid Rent which would have accrued and
          become payable under this Lease pursuant to the provisions of
          paragraph 2 l(c), unpaid Rent shall consist of the sum of:

          (1)  the total Basic Rent for the balance of the Term then remaining
               (with the amount of Basic Rent to be determined by reference to
               fair rental value being the subject of proof by competent
               evidence), plus

          (2)  a computation of the excess of Gross Rent (the term "Gross Rent"
               meaning the sum of (i) rental adjustments payable pursuant to
               paragraph 29 and (ii) Basic Rent) over Basic Rent for the balance
               of the Term then remaining ("Excess Gross Rental"), the assumed
               excess Gross Rental for the calendar year of the default and each
               future calendar year in the Term to be equal to the Excess Gross
               Rental for the calendar year prior to the year in which default
               occurs compounded at a per annum rate equal to the mean average
               rate of inflation for the preceding five (5) calendar years as
               determined by the United States Department of Labor, Bureau of
               Labor Statistics Consumer Price Index (All Urban Consumers) for
               the Metropolitan Area or Region of which San Francisco,
               California is a part.

     (e)  Late Charge. In addition to its other remedies, Landlord shall have
          the right without notice or demand to add to the amount of any payment
          required to be made by Tenant hereunder, and which is not paid on or
          before the date the sum is due, an amount equal to five percent (5%)
          of the delinquency for each month or portion thereof that the
          delinquency remains outstanding to compensate Landlord for the loss of
          the use of the amount not paid and the administrative costs caused by
          the delinquency, the parties agreeing that Landlord's damage by virtue
          of such delinquencies would be difficult to compute and the amount
          stated herein represents a reasonable estimate thereof.

     (f)  Remedies Cumulative. All rights, privileges and elections or remedies
          of the parties are cumulative and not alternative to the extent
          permitted by law and except as otherwise provided herein.

DAMAGE BY FIRE, ETC.

22.  If the Premises or the Building are damaged by fire or other casualty,
     Landlord shall forthwith repair the same, provided such repairs can be made
     within one hundred eighty (180) days from the date of such damage under the
     laws and regulations of the federal, state and local governmental
     authorities having jurisdiction thereof. In such event, this Lease shall
     remain in full force and effect except that Tenant shall be entitled to a
     proportionate reduction of Rent while such repairs to be made hereunder by
     Landlord are being made. Said proportionate reduction shall be based upon
     the extent to which the making of such repairs to be made hereunder by
     Landlord shall interfere with the business carried on by Tenant in the
     Premises. Within twenty (20) days from the date of such damage, Landlord
     shall notify Tenant whether or not such repairs can be made within one
     hundred eighty (180) days from the date of such damage and Landlord's
     determination thereof shall be binding on Tenant. If such repairs cannot be
     made within one hundred eighty (180) days from the date of such damage,
     Landlord shall have the option within thirty (30) days of the date of such
     damage either to: (a) Notify Tenant of Landlord's intention to repair such
     damage and diligently prosecute such repairs, in which event this Lease
     shall continue in full force and effect and the Rent shall be reduced as
     provided herein, or Co) notify Tenant of Landlord's election to terminate
     this Lease as of a date specified in such notice, which date shall be not
     less than thirty (30) nor more than sixty (60) days after notice is given.
     In the event such notice to terminate is given by Landlord, this Lease
     shall terminate on the date specified in such notice. In case of
     termination by either event, the Rent shall be reduced by a proportionate
     amount based upon the extent to which said damage interfered with the
     business carried on by Tenant in the Premises, and Tenant shall pay such
     reduced Rent up to the date of termination. Landlord agrees to refund to
     Tenant any Rent previously paid for any period of time subsequent to such
     date of termination. The repairs to be made hereunder by Landlord shall not
     include, and Landlord shall not be required to repair, any damage by fire
     or other cause to the property of Tenant or any repairs or replacements of
     any paneling, decorations, railings, floor coverings or any alterations,
     additions, fixtures or improvements installed on the premises by or at the
     expense of Tenant. The provisions of Section 1942, subdivision 2, and
     Section 1933, subdivision 4, of the Civil Code of California are superseded
     by the foregoing.

EMINENT DOMAIN

23.  If any part of the Premises shall be taken or appropriated under the power
     of eminent domain or conveyed in lieu thereof, either party shall have the
     right to terminate this Lease at its option. If any part of the Building
     shall be taken or appropriated under power of eminent domain or conveyed in
     lieu thereof, Landlord may terminate this Lease at its option. In either of
     such events, Landlord shall receive subject to the rights of Landlord's
     first mortgage (and Tenant shall assign to Landlord upon demand from
     Landlord) any income, rent, award or any interest therein which may be paid
     in connection with the exercise of such power of eminent domain, and Tenant
     shall have no claim against Landlord for any part of the sums paid by
     virtue 6f such proceedings, whether or not attributable to the value of the
     unexpired Term. If a part of the Premises shall be so taken or appropriated
     or conveyed and neither party hereto shall elect to terminate this Lease
     and the Premises have been damaged as a consequence of such partial taking
     or appropriation or conveyance, Landlord shall restore the Premises
     continuing

                                      11
<PAGE>

     under this Lease at Landlord's cost and expense; provided, however, that
     Landlord shall not be required to repair or restore any injury or damage to
     the property of Tenant or to make any repairs or restoration of any
     alterations, additions, fixtures or improvements installed on the Premises
     by or at the expense of Tenant. Thereafter the Rent for the remainder of
     the Term shall be proportionately reduced, such reduction to be based upon
     the extent to which the partial taking or appropriation or conveyance shall
     interfere with the business carried on by Tenant in the. Premises.
     Notwithstanding anything to the contrary contained in this paragraph, if
     the temporary use or occupancy of any part of the Premises shall be taken
     or appropriated under power of eminent domain during the Term. this Lease
     shall be and remain unaffected by such taking or appropriation and Tenant
     shall continue to pay, in full, all Rent payable hereunder by Tenant during
     the Term; in the event of any such temporary appropriation or taking,
     Tenant shall be entitled to receive that portion of any award which
     represents compensation for the use of or occupancy of the Premises during
     the Term, and Landlord shall be entitled to receive that portion of any
     award which represents the cost of restoration of the Premises and the use
     and occupancy of the Premises after the end of the Term.

SALE BY LANDLORD AND TENANT'S REMEDIES

24.  In the event of a sale or conveyance by Landlord of the Building, the same
     shall operate to release Landlord from any future liability upon any of the
     covenants or conditions, express or implied, herein contained in favor of
     Tenant, and in such event Tenant agrees to look solely to the
     responsibility of the successor in interest of Landlord in and to this
     Lease. This Lease shall not be affected by any such sale and Tenant agrees
     to attorn to the purchaser or assignee. Tenant shall look solely to
     Landlord's interest in the Building for recovery of any judgment from
     Landlord. Landlord, or if Landlord is a partnership, its partners whether
     general or limited, or if Landlord is a corporation, its directors,
     officers or shareholders, shall never be personally liable for any such
     judgment.

RIGHT OF LANDLORD TO PERFORM

25.  All covenants and agreements to be performed by Tenant under any of the
     terms of this Lease shall be performed by Tenant at Tenant's sole cost and
     expense and without any abatement of Rent. If Tenant shall fail to pay any
     sum of money, other than Rent, required to be paid by it hereunder or shall
     fail to perform any other act on its part to be performed hereunder, and
     such failure shall continue for ten (10) days after notice thereof by
     Landlord, Landlord may, but shall not be obligated to do so, and without
     waiving or releasing Tenant from any obligations of the Tenant, make any
     such payment or perform any such act on the Tenant's part to be made or
     performed. All sums so paid by Landlord and all necessary incidental costs
     together with interest thereon at the rate of eighteen percent (18%) per
     annum or the maximum rate permitted by law, whichever is less per annum
     from the date of such payment by the Landlord shall be payable as
     Additional Rent to Landlord on demand, and Tenant covenants to pay such
     sums, and Landlord shall have, in addition to any other right or remedy of
     Landlord, the same right and remedies in the event of the nonpayment
     thereof by Tenant as in the case of default by Tenant in the payment of the
     Rent.

SURRENDER OF PREMISES

26.  (a)  Tenant shall, at least ninety (90) days before the last day of the
          Term, give to Landlord a written notice of intention to surrender the
          Premises on that day, but nothing contained herein shall be construed
          as an extension of the Term or as consent of Landlord to any holding
          over by Tenant.

     (b)  At the end of the term or any renewal thereof or other sooner
          termination of this Lease, Tenant shall peaceably deliver up to
          Landlord possession of the Premises, together with all improvements,
          fixtures or additions thereto by whomsoever made, in the same
          condition as received, or first installed, wear and tear and damage by
          fire, earthquake, act of God or the elements alone excepted. Tenant
          may, upon the termination of this Lease, remove all movable furniture
          and equipment belonging to Tenant, at Tenant's sole cost, title to
          which shall be in Tenant until such termination, repairing any damage
          caused by such removal. Property not so removed shall be deemed
          abandoned by the Tenant, and title to the same shall thereupon pass to
          Landlord.

     (c)  The voluntary or other surrender of this Lease by Tenant, or a mutual
          cancellation thereof, shall not work a merger and shall, at the option
          of Landlord, terminate all or any existing subleases or subtenancies
          or may, at the option of Landlord, operate as an assignment to it of
          any or all such subleases or subtenancies.

WAIVER

27.  If either Landlord or Tenant waives the performance of any term, covenant
     or condition contained in this Lease, such waiver shall not be deemed to be
     a waiver of any subsequent breach of the same or any other term, covenant
     or condition contained herein. The acceptance of Rent by Landlord shall not
     constitute a waiver of any preceding breach by Tenant of any term, covenant
     or condition of this Lease, regardless of Landlord's knowledge of such
     preceding breach at the time Landlord accepted such Rent. Failure by
     Landlord to enforce any of the terms, covenants or conditions of this Lease
     for any length of time shall not be deemed to waive or to decrease the
     right of Landlord to insist thereafter upon strict performance by Tenant.
     Waiver by Landlord of any term, covenant or condition contained in this
     Lease may only be made by a written document signed by Landlord.

                                      12
<PAGE>

NOTICES

28.  All notices and demands which may or are required to be given by either
     party to the other hereunder shall be in writing. All notices and demands
     by Landlord to Tenant shall be sent by United States certified or
     registered mail, or Federal Express or singular overnight carrier, postage
     or freight prepaid, addressed to Tenant at the Premises, or to such other
     place as Tenant may from time to time designate in a notice to Landlord.
     All notices and demands by Tenant to Landlord shall be sent by United
     States certified or registered mail, or Federal Express of similar
     overnight carrier, postage or freight prepaid, addressed to Landlord at the
     address specified in the Basic Lease Information, or to such other firm or
     to such other place as Landlord may from time to time designate in a notice
     to Tenant.

RENTAL ADJUSTMENT

29.  In addition to Basic Rent provided to be paid hereunder, Tenant shall pay
     as Rent Tenant's Proportionate Share of Basic Operating Cost in the manner
     set forth below.

     (a)  Definition: For purposes hereof, the terms used in this Paragraph 29
          shall have the following meanings:

          (1)    "Basic Operating Cost" shall mean all expenses and costs of
                 every kind and nature which Landlord shall pay or become
                 obligated to pay because of or in connection with the ownership
                 and operation of the Building and supporting facilities of the
                 Building, and such additional facilities now and in subsequent
                 years as may be determined by Landlord to be necessary to the
                 Building, including, but not limited to the following:

          (i)    Wages, salaries and related expenses and benefits of all on-
                 site and off-site employees engaged directly in the operation,
                 management, maintenance, engineering and security of the
                 Building, and the costs of an office in the Building; provided,
                 however, that Basic Operating Cost shall not include leasing
                 commissions paid to any real estate broker, salesperson or
                 agent.

          (ii)   Supplies, materials and rental of equipment used in the
                 operation, management and maintenance of the Building.

          (iii)  Utilities, including water and power, heating, lighting, air
                 conditioning and ventilating of the Building.

          (iv)   All maintenance, janitorial and service agreements for the
                 Building and the equipment therein, including, without
                 limitation, alarm services, window cleaning and elevator
                 maintenance.

          (v)    A management cost recovery determined by Landlord equal to
                 three percent (3%) of Gross Rent derived from the Building.

          (vi)   Legal expenses and the cost of audits by certified public
                 accountants; provided, however, that legal expenses chargeable
                 as Basic Operating Cost shall not include the cost of
                 negotiating leases, collecting rents, evicting tenants nor
                 shall it include costs incurred in legal proceedings with or
                 against any tenant or to enforce the provisions of any lease.

          (vii)  All insurance premiums and costs, including but not limited to,
                 the premiums and cost of fire, casualty and liability coverage
                 and rental abatement and earthquake insurance (if Landlord
                 elects to provide such coverage) applicable to the Building and
                 Landlord's personal property used in connection therewith.

          (viii) Repairs, replacements and general maintenance (excluding
                 repairs and general maintenance paid by proceeds of insurance
                 or by Tenant or other third parties, and alterations
                 attributable solely to tenants of the Building other than
                 Tenant).

          (ix)   All maintenance costs relating to public and service areas of
                 the Building, including (but without limitation) sidewalks,
                 landscaping, service areas, mechanical rooms and Building
                 exteriors.

          (x)    All taxes, service payments in lieu of taxes, annual or
                 periodic license or use fees, fees, real estate taxes,
                 impositions or charges imposed upon or levied in connection
                 with use of the Building to raise funds for public transit,
                 housing or other environmental, sociological or fiscal effects
                 of the Building or land use, assessments whether general or
                 special, ordinary and extraordinary, unforeseen as well as
                 foreseen, of any kind which are assessed, levied, charged,
                 confirmed or imposed by any public authority upon the Building,
                 the land upon which it is located, Building operations or Rent
                 payable under this Lease (or any portion or component thereof),
                 excepting only inheritance or estate taxes imposed upon or
                 assessed against the interest of any person in the Building or
                 any part thereof or interest therein, and taxes computed upon
                 the basis of the net income of the owners of the Building or
                 any part thereof or interest therein.

                                      13
<PAGE>

          (xi) Amortization (together with reasonable financing charges) of
               capital improvement made to the Building subsequent to the Term
               Commencement Date which will improve the operating efficiency of
               the building or which may be required to comply with laws,
               ordinances, rules or regulations promulgated, adopted or enforced
               after completion of the initial construction of the Building and
               improvements of the Premises pursuant to the Office Lease
               Improvement Agreement.

          Notwithstanding anything to the contrary herein contained, Basic
          Operating Cost shall not include (aa) the initial construction cost of
          the Building; (bb) depreciation on the initial construction of the
          Building; (cc) the cost of providing Tenant Improvements to Tenant or
          any other tenant; (dd) debt service (including, but without
          limitation, interest, principal and any impound payment) required to
          be made on any mortgage or deed of trust recorded with respect to the
          Building and/or the real property on which the Building is located
          other than debt service and financing charges imposed pursuant to
          paragraph 29(a)(1)(xi) above; and (ee) the cost of special services,
          goods or materials provided to any tenant. In the event that the
          Building is not fully occupied during any fiscal year of the Term as
          determined by Landlord, an adjustment shall be made in computing the
          Basic Operating Cost for such year so that Basic Operating Cost shall
          be computed as though the Building had been one hundred percent (100%)
          occupied; provided, however, that in no event shall Landlord be
          entitled to collect in excess of one hundred percent (100%) of the
          total Basic Operating Cost from all of the tenants in the Building
          including Tenant. All costs and expenses shall be determined in
          accordance with generally accepted accounting principles which shall
          be consistently applied (with accruals appropriate to Landlord's
          business). Basic Operating Cost shall not include specific costs
          incurred for the account of, separately billed to and paid by specific
          tenants.

          (2)  "Estimated Basic Operating Cost" for any particular year shall
               mean Landlord's estimate of the Basic Operating Cost for such
               fiscal year made prior to commencement of such fiscal year as
               hereinafter provided. Landlord shall have the right from time to
               time to revise its fiscal year and interim accounting periods so
               long as the periods as so revised are reconciled with prior
               periods in accordance with generally accepted accounting
               principles applied in a consistent manner.

          (3)  "Basic Operating Cost Adjustment" shall mean the difference
               between Basic Operating Cost and Estimated Basic Operating Cost
               for any fiscal year determined as hereinafter provided.

     (b)  Payment of Estimated Basic Operating Cost.

          During the last month of each fiscal year during the Term, or as soon
          thereafter as practicable, Landlord shall give Tenant written notice
          of the Estimated Basic Operating Cost for the ensuing fiscal year. The
          Estimated Basic Operating Cost for the fiscal year in which the
          Scheduled Term Commencement Date falls is set forth in the Basic Lease
          Information sheet. Tenant shall pay Tenant's Proportionate Share of
          the Estimated Basic Operating Costs with installments of Basic Rent
          required to be paid pursuant to paragraph 3 above for the fiscal year
          to which the estimate applies in monthly installments on the first day
          of each calendar month during such year, in advance. Such payment
          shall be construed to be Rent for all purposes hereof. If at any time
          during the course of a fiscal year, Landlord determines that Basic
          Operating Cost will apparently vary from the then Estimated Basic
          Operating Cost by more than five percent (5%), Landlord may, by
          written notice to Tenant, revise the Estimated Basic Operating Cost
          for the balance of such fiscal year and Tenant shall pay Tenant's
          Proportionate Share of the Estimated Basic Operating Cost as so
          revised for the balance of the then current fiscal year on the first
          day of each calendar month thereafter, such revised installment
          amounts to be Rent for all purposes hereof.

     (c)  Computation of Basic Operating Cost Adjustment.

          Within one hundred twenty (120) days after the end of each fiscal year
          as determined by Landlord or as soon thereafter as practicable,
          Landlord shall deliver to Tenant a statement of Basic Operating Cost
          for the fiscal year just ended, accompanied by a computation of Basic
          Operating Cost Adjustment. If such statement shows that Tenant's
          payment based upon Estimated Basic Operating Cost is less than
          Tenant's Proportionate Share of Basic Operating Cost, then Tenant
          shall pay the difference within twenty (20) days after receipt of such
          statement, such payment to constitute additional Rent hereunder. If
          such statement shows that Tenant's payments of Estimated Basic
          Operating Cost exceed Tenant's Proportionate Share of Basic Operating
          Costs, then (provided that Tenant is not in default under this Lease),
          Tenant shall receive a credit for the amount of such payment against
          Tenant's obligation for payment of Tenant's Proportionate Share of
          Estimated Basic Operating Cost next becoming due hereunder. If this
          Lease has been terminated or the Term hereof has expired prior to the
          date of such statement, then the Basic Operating Cost Adjustment shall
          be paid by the appropriate party within twenty (20) days after the
          date of delivery of the statement.

     (d)  Net Lease.

          This shall be a net lease and Base Rent shall be paid to Landlord
          absolutely net of all costs and expenses. The provisions for payment
          of Basic Operating Cost by means of periodic payments of Tenant's
          Proportionate Share of Estimated Basic Operating Cost and the Basic
          Operating Cost Adjustment are intended to pass on to Tenant and
          reimburse Landlord for all cost and expenses of the nature described
          in paragraph 29(a)(1) above incurred in connection with ownership and
          operation of the Building and such

                                      14
<PAGE>

          additional facilities now and in subsequent years as may be determined
          by Landlord to be necessary to the Building.

     (e)  Tenant Audit.

          Tenant shall have the right, at Tenant's expense and upon not less
          than forty-eight (48) hours prior written notice to Landlord to review
          at reasonable times Landlord's books and records for any fiscal year a
          portion of which falls within the Term for purposes of verifying
          Landlord's calculations of Basic Operating Cost and Basic Operating
          Cost Adjustments. In the event that Tenant shall dispute the amount
          set forth in any statement provided by Landlord under paragraph 29(c)
          above, Tenant shall have the right not later than twenty (20) days
          following the receipt of such statement, and upon condition that
          Tenant shall first deposit with Landlord the full amount in dispute,
          to cause Landlord's books and records with respect to such fiscal year
          to be audited by certified public accountants selected by Tenant
          subject to Landlord's reasonable right of approval. The Basic
          Operating Cost Adjustment shall be appropriately adjusted on the basis
          of such audit. If such audit discloses a liability for a refund or
          credit by Landlord to Tenant in excess of ten percent (10%) of
          Tenant's Proportionate Share of the Basic Operating Cost Adjustment
          previously reported, the cost of such audit shall be borne by
          Landlord. Otherwise the cost of such audit shall be paid by Tenant. If
          Tenant shall not request an audit in accordance with the provisions of
          this paragraph 29(e) within twenty (20) days of receipt of Landlord's
          statement provided pursuant to paragraph 29(d), such statement shall
          be final and binding for all purposes hereof.

TAXES PAYABLE BY TENANT

30.  (a)  Tenant shall pay before delinquency any and all taxes levied or
          assessed and which become payable by Landlord (or Tenant) during the
          Term of this Lease, whether or not now customary or within the
          contemplation of the parties hereto, which are based upon, measured by
          or otherwise calculated with respect to: (a) the value of Tenant's
          equipment, furniture, fixtures or other personal property located in
          the Premises; (b) the value of any leasehold improvements,
          alterations, or additions made in or to the Premises, regardless of
          whether title to such improvements, alterations or additions shall be
          in Tenant or Landlord; or (c) this transaction or any document to
          which Tenant is a party creating or transferring an interest or an
          estate in the Premises.

     (b)  In the event that it shall not be lawful for Tenant so to reimburse
          Landlord, the Rent shall be revised to net Landlord the same net rent
          after imposition of any such tax upon Landlord as would have been
          payable to Landlord prior to the imposition of any such tax. All taxes
          payable to Tenant under this paragraph 30 shall be additional rental.

SUCCESSORS AND ASSIGNS

31.  Subject to the provisions of paragraph 10 hereof, the terms, covenants and
     conditions contained herein shall be binding upon and inure to the benefit
     of the heirs, successors, executors, administrators and assigns of the
     parties hereto.

ATTORNEYS' FEES

32.  In the event that any action or proceeding is brought to enforce any term,
     covenant or condition of this Lease on the part of Landlord or Tenant, the
     prevailing party in such litigation shall be entitled to reasonable
     attorneys' fees to be fixed by the court in such action or proceeding.

LIGHT AND AIR

33.  No diminution of light, air or view by any structure which may hereafter be
     erected (whether or not by Landlord) shall entitle Tenant to any reduction
     of Rent, result in any liability of Landlord to Tenant, or in any other way
     affect this Lease or Tenant's obligations hereunder.

PUBLIC TRANSPORTATION INFORMATION

34.  Tenant shall establish and maintain during the Term hereof a program to
     encourage maximum use of public transportation by personnel of Tenant
     employed on the Premises, including without limitation the distribution to
     such employees of written materials explaining the convenience and
     availability of public transportation facilities adjacent or proximate to
     the Building, staggering working hours of employees, and encouraging use of
     such facilities, all at Tenant's sole reasonable cost and expense.

                                      15
<PAGE>

MISCELLANEOUS

35.  (a)  The term "Premises" shall be deemed to include (except where such
          meaning would be clearly repugnant to the context) the office space
          demised and improvements now or at any time hereinafter comprising or
          built in the space hereby demised

     (b)  The paragraph headings hereto are for convenience of reference and
          shall in no way define, increase, limit or describe the scope or
          intent of any provision of this Lease.

     (c)  The term "Landlord" in these presents shall include the Landlord, its
          successors and assigns. In any case where this lease is signed by more
          than one person, the obligations hereunder shall be joint and several.

     (d)  The term "Tenant" or any pronoun used in place thereof shall indicate
          and include the masculine or feminine, the singular or plural number,
          individuals, firms or corporations, and their and each of their
          respective successors, executors, administrators and permitted
          assigns, according to the context hereof.

     (e)  Time is of the essence of this Lease and all of its provisions.

     (f)  This Lease shall in all respects be governed by the laws of the State
          of California.

     (g)  This Lease, together with its exhibits, contains all the agreements of
          the parties hereto and supersedes any previous negotiations.

     (h)  There have been no representations made by the Landlord or
          understandings made between the parties other than those set forth in
          this Lease and its exhibits.

     (i)  This Lease may not be modified except by a written instrument by the
          parties hereto.

     (j)  If for any reason whatsoever any of the provisions hereof shall be
          unenforceable or ineffective, all of the other provisions shall be and
          remain in full force and effect.

     (k)  See Addenda #1 - #3 attached hereto and made a part hereof. If the
          term of the printed form and the terms of the Addendas are in
          conflict, the terms of the Addendas will prevail.

LEASE EFFECTIVE DATE

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

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

                  "LANDLORD"

                  SPIEKER PROPERTIES, L.P.
                  a California limited partnership

                  By: Spieker Properties, Inc.
                      a Maryland corporation

                  By:  /s/ Peter Schnugg
                     -------------------------------
                       Peter Schnugg

                  Its: Senior Vice President
                      ------------------------------

                  Date:  4-7-97
                       -----------------------------

                  "TENANT"

                  CROSSROUTE SOFTWARE, INCORPORATED
                  a California corporation

                  By:  /s/ Kenneth Ross
                     -------------------------------
                       Kenneth Ross

                  Its: President
                       -----------------------------
                  Date:
                       -----------------------------

                                      16
<PAGE>

     LEASE DATE:    March 28, 1997

     LANDLORD:      SPIEKER PROPERTIES,
                    L.P. a California limited partnership

     TENANT:        CROSSROUTE SOFTWARE, INCORPORATED
                    a California corporation



     ADDENDUM #1 RENT
     ----------------

     Rent for the Premises shall be as follows:

          Months 1 - 12
          -------------
          6/1/97 - 5/31/98

          Base Rent                   $13,243.00
          Basic Operating Costs
          (1997 Est.)                   3,836.00
                                      ----------
                                      $17,079.00 per month

          Months 13 - 24
          --------------
          6/1/98 - 5/31/99

          Base Rent                   $13,768.00
          Basic Operating Costs
          (1997 Est.)                   3,836.00
                                      ----------
                                      $17,604.00 per month

          Months 25 - 36
          --------------
          6/1/99 - 5/31/00

          Base Rent                   $14,294.00
          Basic Operating Costs
          (1997 Est.)                   3,836.00
                                      ----------
                                      $18,130.00 per month

          Months 37 - 48
          --------------
          6/1/00 - 5/31/01

          Base Rent                   $14,819.00
          Basic Operating Costs
          (1997 Est.)                   3,836.00
                                      ----------
                                      $18,655.00 per month

          Months 49 - 60
          --------------
          6/1/01 - 5/31/02

          Base Rent                   $15,345.00
          Basic Operating Costs
          (1997 Est.)                   3,836.00
                                      ----------
                                      $19,181.00 per month

     Rental rate includes a $.73 (1997 estimate) per square foot per month
     allowance for real estate taxes, assessments, insurance, normal routine
     maintenance, management, five (5) days per week janitorial service, and
     normal operating hours utilities. Should the actual expenses be more or
     less than this allowance, the difference shall be credited to Tenant, or
     owed by Tenant, as the case may be.

                                      17
<PAGE>

     ADDENDUM #2 TENANT IMPROVEMENTS
     -------------------------------

     Landlord, at its sole cost, shall provide the following tenant
     improvements:

          -  Shampoo carpets throughout office area
          -  Touch-up paint as necessary throughout office area

     ADDENDUM #3 LETTER OF CREDIT
     ----------------------------

     Upon execution hereof., Tenant shall provide Landlord with a Letter of
     Credit from a United States bank acceptable to Landlord, and naming
     Landlord as beneficiary in an amount equal to $51,236.00 (fifty one
     thousand two hundred thirty six dollars) and in the form and substance
     satisfactory to Landlord. This Letter of Credit shall be held throughout
     the entire length of the lease term. Said Letter of Credit shall serve as
     security for the faithful performance and observance by Tenant of the
     terms, provisions and conditions of this Lease, including without
     limitation, the surrender of possession of the Premises to Landlord as
     herein provided. The Letter of Credit shall be payable at sight when
     accompanied by Landlord's signed statement that Tenant has failed to pay
     any rent or other amount due under the Lease and evidence of notice from
     Landlord to Tenant per the terms of this Lease.

     "Landlord"
     Spieker Properties, L. P.
     a California limited partnership

     By:  Spieker Properties, Inc.
          ------------------------
          a Maryland corporation


     By:  /s/ Peter Schnugg
          ------------------------
          Peter H. Schnugg

     Its: Senior Vice President
          ------------------------

     Date:  4-7-97
          ------------------------


     "TENANT"
     Crossroute Software, Incorporated
     a California corporation

     By:  /s/ Kenneth Ross
          ------------------------
          Kenneth Ross

     Its: President
          ------------------------

     Date:   3/31/97
          ------------------------

                                      18
<PAGE>

                             Rules and Regulations

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

     2.   Tenant must use Landlord's blinds in all exterior and atrium window
offices. No awning shall be permitted on any part of the Premises. Tenant shall
not place anything against or near glass partitions or doors or windows which
may appear unsightly from outside the Premises.

     3.  Tenant shall not obstruct sidewalks, halls, passages, exits, entrances,
elevators, escalators or stairways of the Building. The halls, passages, exits,
entrances, shopping malls, elevators, escalators and stairways are not for the
general public, and Landlord shall in all cases retain the right to control and
prevent access thereto of all persons whose presence in the judgement of
Landlord would be prejudicial to the safety, character, reputation and interests
of the Building and its tenants; provided that nothing herein contained shall be
construed to prevent such access to persons with whom any tenant normally deals
in the ordinary course of its business, unless such persons are engaged in
illegal activities. No tenant and no employee or invitee of any tenant shall go
upon the roof of the Building.

     4.   The directory of the Building will be provided exclusively for the
display of the name and location of Tenants only, and Landlord reserves the
right to execute any other names therefrom.

     5.   All cleaning and janitorial services for the Building and the Premises
shall be provided exclusively through Landlord, and except with the written
consent of Landlord, no person or persons other than those approved by Landlord
shall be employed by Tenant or permitted to enter the Building for the purpose
of cleaning the same. Tenant shall not cause any unnecessary labor by
carelessness or indifference to the good order and cleanliness of the Premises.
Landlord shall not in any way be responsible to any Tenant for any loss of
property on the Premises, however occurring, or for any damage to any Tenant's
property by the janitor or any other employee or any other person.

     6.  Landlord will furnish Tenant, free of charge, with two keys to each
door lock in the Premises. Landlord may make a reasonable charge for any
additional keys. Tenant shall not make or have made additional keys, and Tenant
shall not alter any lock or install a new additional lock or bolt on any door of
its Premises. Tenant, upon the termination of its tenancy, shall deliver to
Landlord the keys of all doors which have been furnished to Tenant, and in the
event of loss of any keys so furnished, shall pay Landlord therefor.

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

     8.   Any freight elevator shall be available for use by all tenants in the
Building, subject to such reasonable scheduling as Landlord in its discretion
shall deem appropriate, No equipment, materials, furniture, packages, supplies,
merchandise or other property will be received in the Building or carried in the
elevators except between such hours and in such elevators as may be designated
by Landlord.

     9.   Tenant moves and deliveries of large quantities of furniture,
equipment or supplies must be accomplished after 5:30 pm on weekdays or anytime
on weekends and must be coordinated with Landlord.

     10.  Tenant shall not place a load upon any floor of the Premises which
exceeds the load per square foot which such floor was designed to carry and
which is allowed by law. Landlord shall have the right to prescribe the weight,
size and position of all equipment, materials, furniture or other property
brought into the Building. Heavy objects, if such objects are considered
necessary by Tenant, as determined by Landlord, shall stand on such platforms as
determined by Landlord to be necessary to properly distribute the weight.
Business machines and mechanical equipment belonging to Tenant, which cause
noise or vibration that may be transmitted to the structure of the Building or
to any space therein to such a degree as to be objectionable to Landlord or to
any tenants in the Building, shall be placed and maintained by Tenant, at
Tenant's expense, on vibration eliminators or other devices sufficient to
eliminate noise or vibration. The persons employed to move such equipment in or
out of the Building must be acceptable to Landlord. Landlord will not be
responsible for loss of, or damage to, any such equipment or other property from
any cause, and all damage done to the Building by maintaining or moving such
equipment or other property shall be repaired at the expense of Tenant.

     11.  Tenant shall not use or keep in the Premises any kerosene, gasoline
or inflammable or combustible fluid or materials other than those limited
quantities necessary for the operation or maintenance of office equipment.
Tenant shall not use or permit to be used in the Premises any foul or noxious
gas or substance, or permit or allow the Premises to be occupied or used in a
manner offensive or objectionable to Landlord or other occupants of the Building
by reason of noise, odors or vibrations, nor shall Tenant bring into or keep in
or about the Premises any birds or animals.

     12.  Tenant shall not use any method of heating or air-conditioning other
than that supplied by Landlord.

                                  Exhibit "A"
                                   Page -1-
<PAGE>

     13.  Tenant shall not waste electricity, water or air-conditioning and
agrees to cooperate fully with Landlord to assure the most effective operation
of the Building's heating and air-conditioning and to comply with any
governmental energy-saving rules, laws and regulations of which Tenant has
actual notice, and shall refrain from attempting to adjust controls other than
room thermostats for Tenant's use. Tenant shall keep corridor doors closed, and
shall close window coverings at the end of each business day. Heat and air-
conditioning shall be provided during ordinary business hours of generally
recognized business days but not less than the hours of 8:00 am to 6:00 pm on
Monday through Friday (excluding in any event Saturdays, Sundays and legal
holidays it being understood that legal holidays shall mean and refer to those
holidays of which Landlord provides Tenant with reasonable prior written notice
which shall in any event include those holidays on which the New York Stock
Exchange is closed).

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

     15.  Landlord reserves the right to exclude from the building between the
hours of 6:00 pm and 7:00 am the following day, or such other hours as may be
established from time to time by Landlord, and on Saturdays, Sundays and legal
holidays, any person unless that person is known to the person or employee in
charge of the Building and has a pass or is properly identified. Tenant shall be
responsible for all persons for whom it requests passes and shall be liable to
Landlord for all acts of all such persons. Landlord shall not be liable for
damages for any error with regard to the admission to or exclusion from the
Building of any person. Landlord reserves the right to prevent access to the
Building in case of invasion, mob, riot, public excitement or other commotion by
closing the doors or by other appropriate action.

     16.  Tenant shall close and lock the doors of its Premises and entirely
shut off all water faucets or other water apparatus, and electricity, gas or air
outlets before Tenant and employees leave the Premises. Tenant shall be
responsible for any damage or injuries sustained by other tenants or occupants
of the Building or by Landlord for noncompliance with this rule.

     17.  Tenant shall not obtain for use on the Premises ice, drinking water,
food beverage, towel or other similar services or accept barbering or
bootblacking services upon the Premises, except at such hours and under such
regulations as may be fixed by Landlord.

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

     19.  Tenant shall not sell, or permit the sale at retail, of newspapers,
magazines, periodicals, theater tickets or any other goods or merchandise to the
general public in or on the Premises. Tenant shall not make any room-to-room
solicitation of business from other tenants in the Building. Tenant shall not
use the Premises for any business or activity other than that specifically
provided for in Tenant's Lease.

     20.  Tenant shall not install any radio or television antenna, loudspeaker
or other device on the roof or exterior walls of the Building. Tenant shall, not
interfere with radio or television broadcasting or reception from or in the
Building or elsewhere.

     21.  Tenant shall not mark, drive nails, screw or drill into the
partitions, woodwork or plaster or in any way deface the Premises or any part
thereof, except to install normal wall hangings. Landlord reserves the right to
direct electricians as to where and how telephone and telegraph wires are to be
introduced to the Premises, Tenant shall not cut or bore holes for wires. Tenant
shall not affix any floor covering to the floor of the Premises in any manner
except as approved by Landlord. Tenant shall repair any damage resulting from
noncompliance with this rule.

     22.  Tenant shall not install, maintain or operate upon the Premises
any vending machine without the written consent of Landlord.

     23.  Canvassing, soliciting and distribution of handbills or any other
written material, and peddling in the Building are prohibited, and each tenant
shall cooperate to prevent same.

     24.   Landlord reserves the right to exclude or expel from the Building any
person who, in Landlord's judgement, is intoxicated or under the influence of
liquor or drugs or who is in violation of any of the Rules and Regulations of
the Building.

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

     26.  The Premises shall not be used for the storage of merchandise held
for sale to the general public, or for lodging or for manufacturing or any kind,
nor shall the Premises be used for any improper, immoral or objectionable
purpose. No cooking shall be done or permitted by any tenant on the Premises,
except that used by Tenant of Underwriters' Laboratory-approved equipment for
brewing coffee, tea, hot chocolate and similar beverages shall be permitted, and
the use of a microwave shall be permitted, providing that such equipment and use
is in accordance with all applicable federal, state, county and city laws,
codes, ordinance, rules and regulations.

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

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

                                  Exhibit "A"
                                   Page -2-
<PAGE>

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

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

     31   The requirements of Tenants will be attended to only upon appropriate
application to the off ice of the Building by an authorized individual.
Employees of Landlord shall not perform any work or do anything outside of their
regular duties unless under special instructions from Landlord. and no employee
of Landlord will admit any person (Tenant or otherwise) to any office without
specific instructions from Landlord.

     32.  Landlord may waive any one or more of these Rules and Regulations for
the benefit of Tenant or any other tenant, but no such waiver by Landlord shall
be construed as a waiver of such Rules and Regulations in favor of Tenant or any
other Tenant, or prevent Landlord from thereafter enforcing any such Rules and
Regulations against any or all of the tenants of the Building.

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

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

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

     36.  Tenant shall not occupy or permit any portion of Demised Premises to
be occupied as an office that is not generally consistent with the character and
nature of all other tenancies in the Building, or is (a) for an employment
agency, a public stenographer or typist, a labor union office, a physician's or
dentist's office, a dance or music studio, a school, a beauty salon or barber
shop, the business of photographic, multilith or multigraph reproductions or
offset printing (not precluding using any part of Demised Premises for
photographic, multilith or multigraph reproductions solely in connection with
Tenant's own business and/or activities), a restaurant or bar, an establishment
for the sale of confectionery or soda or beverages or sandwiches or ice cream or
baked goods, an establishment for the preparation of dispensing or consumption
of food or beverages (of any kind) in any manner whatsoever, or as a news or
cigar stand, or as a radio or television or recording studio, theater or
exhibition-hall, for manufacturing for the storage of merchandise or for the
sale of merchandise, goods or property of any kind at auction, or for lodging,
sleeping or for any immoral purpose, or for any business which would tend to
generate a large amount of foot traffic in or about the Building or the land
upon which it is located, or any of the areas used in the operation of the
Building, including but not limited to any use (i) for a banking, trust company,
depository, guarantee, or safe deposit business, (ii) as a savings bank, or as a
savings and loan association, or as a loan company, (iii) for the sale of
travelers checks, money orders, drafts, foreign exchange or letters of credit or
for the receipt of money for transmission, (iv) as a stock broker's or dealer's
office or for the underwriting of securities, (v) a government office or foreign
embassy or consulate, or (vi) tourist or travel bureau, or (b) a use which
conflicts with any so-called "exclusive" then in favor of, or is for any use the
same as that stated in any percentage lease to another tenant of the Building or
the Site, or (c) a use which would be prohibited by any other portion of this
Lease (including, but not limited to any Rules and Regulations then in effect)
or in violation of law. Tenant shall not engage or pay any employees on Demised
Premises, except those actually working for Tenant on Demised Premises nor shall
Tenant advertise for laborers giving an address at Demised Premises.

     37.  If Demised Premise is or becomes infested with vermin as a result of
the use or any misuse or neglect of Demised Premises by Tenant, its agents,
servants, employees, contractors, visitors or licensees, Tenant shall forthwith
at Tenant's expense cause the same to be exterminated from time to time to the
satisfaction of Landlord and shall employ such licensed exterminators as shall
be approved in writing in advance by Landlord.

     38.  Tenant, Tenant's agents, servants, employees, contractors, licensees
or visitors shall not park any vehicles in any driveways, service entrances, or
areas posted "No Parking".

     39.  Tenant shall install and maintain, at Tenant's sole cost and expense,
an adequate visibly marked (at all times properly operational) fire extinguisher
next to any duplicating or photocopying machine or similar heat producing
equipment, which may or may not contain combustible material, in Demised
Premises.

     40.  Smoking will not be permitted in the Building.

     41.  Landlord reserves the right to assess a $100 penalty to the Tenant
whose employee(s) after repeated warnings continue to abuse parking privileges.
Landlord also has the right to tow any vehicle(s) in violation at the vehicle
owner's expense.

     42.  Tenant shall not use lobbies or other common areas of the Building
for promotion, such as parties, displays or advertisements.

     43.  Tenants may reserve the Tenant Conference Room through the Building
Manager on a first come, first served basis. Tenants shall comply with all
check-in and cleanup of the conference room or Landlord reserves the right to
assess a reasonable fee for maid service.

                                  Exhibit "A"
                                   Page -3-
<PAGE>

                        Outline of Premises, Suite 180
                            Approximately 5,255 rsf

                                     (Map)

                                  Exhibit "B"
                                   Page -1-
<PAGE>

                          Form of Tenant Certificate

CrossRoute Software: Incorporated
---------------------------------

555 Twin Dolphin Drive, Suite 190
---------------------------------

Redwood City, California 94065
------------------------------



RE:  Premises located at 555 Twin Dolphin Drive, Suite 180
     Redwood City, California 94065



Gentlemen:

The undersigned, as Tenant under that certain lease (the "Lease") dated March
                                                                        -----
28, 1997,
---------

made with Spieker Properties, L.P. as
          ------------------------

Landlord (the "Landlord"), does hereby certify:

1. That the copy of the Lease attached hereto as Exhibit A is a true and
   complete copy of the Lease, and that there are no amendments, modifications
   or extensions of or to the Lease and the Lease is now in full force and
   effect.

2. That its leased premises at the above location have been completed in
   accordance with the terms of the Lease, that it has accepted possession of
   said premises, and that it now occupies the same.

3. That it began paying rent on ________________, 19__, and that, save only as
   may be required by the terms of the Lease, no rental has been paid in
   advance, nor has the undersigned deposited any sums with the Landlord as
   security.

4. That there exists no defenses or offsets to enforcement of the Lease by the
   Landlord and, so far as is known to the undersigned, the Landlord is not, as
   of the date hereof, in default in the performance of the Lease, nor has the
   Landlord committed any breach thereof, nor has any event occurred which, with
   the passage of time or the giving of notice, or both, would constitute a
   default or breach by the Landlord.

   The undersigned acknowledges that you are relying on the above representation
   of the undersigned in (advancing funds to purchase the existing first
   mortgage loan covering the building in which the leased premises are located)
   (in purchasing the building in which the leased premises are located) and
   does hereby warrant and affirm to and for your benefit, and that of your
   successors and assigns, that each of the foregoing representations is true,
   correct and complete as of the date hereof.


Dated:_________________________



By_____________________________
     Kenneth Ross

     Its_______________________

                                  Exhibit "D"
                                   Page -1-
<PAGE>

                              LEASE AMENDMENT #1
                              ------------------


ORIGINAL LEASE DATE           March 28, 1997


LEASE AMENDMENT DATE:         October 6, 1997


LANDLORD:                     Spieker Properties, L.P.
                              a California Limited Partnership


TENANT:                       CrossRoute Software, Incorporated
                              a California Corporation

Landlord and Tenant, by executing this Lease Amendment as provided do hereby
amend the Original Lease referred to above as follows:

1.   TERM
     ----

     The term of the Lease shall be extended so that the Scheduled Term
     Expiration Date, as defined per the Basic Lease Information within the
     Original Lease Agreement, shall be October 31, 2002.

2.   PREMISES
     --------

     The Premises of the Lease as defined per the Basic Lease Information shall
     be amended such that effective November 1, 1997, approximately 17,198
     square feet of rentable space on the sixth floor of 555 Twin Dolphin Drive,
     known as Suite #600, shall be incorporated into the Original Lease
     Agreement, and approximately 5,255 square feet of rentable space on the
     first floor of 555 Twin Dolphin Drive, known as Suite #180, shall be
     reduced from the Original Lease Agreement. Total square footage shall
     increase from 5,255 to 17,198 rentable square feet.


3.   RENTAL RATE
     -----------

     Months 1 - 12
     (11/01/97 - 10/31/98)    Base Rent           $47,982.42
                              Op. Exp. (est '97)  $12.210.58
                                                  ----------
                              Total Rent          $60,193.00  per month

     Months 13 - 24
     11/01/98 - 10/31/99      Base Rent           $49,702.22
                              Op. Exp. (est '97)  $12,210.58
                                                  ----------
                              Total Rent          $61,912.80  per month

     Months 25 - 36
     11/01/99 - 10/31/2000    Base Rent           $51,422.02
                              Op. Exp. (est '97)  $12.210.58
                                                  ----------
                              Total Rent          $63,632.60  per month

     Months 37 - 48
     11/01/2000 - 10/31/2001  Base Rent           $53,141.82
                              Op. Exp. (est '97)  $12.210.58
                                                  ----------
                              Total Rent          $65,352.40  per month

     Months 49 - 60
     11/01/2001 - 10/31/2002  Base Rent           $54,861.62
                              Op. Exp. (est '97)  $12,210.58
                                                  ----------
                              Total Rent          $67,072.20  per month

4.   PROPORTIONATE SHARE
     -------------------

     Tenant's Share, as defined per the Basic Lease Information within the
     Original Lease Agreement shall increase effective November 1, 1997 from
     2.65% to 8.66%.
<PAGE>

CrossRoute Software, Incorporation
Lease Amendment #1
Page Two

5.   SECURITY DEPOSIT
     ----------------

     The of the Security Deposit, as defined in the Basic Lease Information of
     the Lease Agreement, shall increase from $17,079.00 to $60,193.00.

6.   LETTER OF CREDIT
     ----------------

     The amount of the Letter of Credit, as defined in Addendum #3 of the
     Original Lease Agreement, shall increase from $51,236.00 to $180,579.00.

7.   TENANT IMPROVEMENTS
     -------------------

     Landlord, at its sole cost, shall provide the following tenant
     improvements:

     .    New building standard carpet throughout entire office
     .    New paint throughout entire office

8.   All other terms and conditions of the original Lease Agreement shall apply
     to this Lease Amendment #1. Agreed to this 7th day of October, 1997.



     LANDLORD:

     Spieker Properties, L. P.
     a California Limited Partnership

     By:  Spieker Properties, Inc.
          -----------------------------------
          a Maryland corporation

     Its: General Partner

     By: /s/  Peter H. Schnugg
         -----------------------------------
          Peter H. Schnugg

     Its: Senior Vice President
          ----------------------------------

     Date:  10-16-97
           ---------------------------------


     TENANT:

     Crossroute Software, Incorporated
     a California corporation

     By: /s/ Kenneth Ross
        ------------------------------------
         Kenneth Ross

     Its:  President
          ----------------------------------

     Date:  10/7/97
           ---------------------------------
<PAGE>

                              EXPANSION AGREEMENT
                              -------------------

AMENDMENT NUMBER 2 TO THAT LEASE DATED MARCH 28,1997 AND AS AMENDED BY LEASE
AMENDMENT #I DATED OCTOBER 6, 1997 BETWEEN SPIEKER PROPERTIES, L.P., AS
LANDLORD, AND CROSSROUTE SOFTWARE, INCORPORATED, AS TENANT, FOR PREMISES LOCATED
AT 555 TWIN DOLPHIN DRIVE, REDWOOD CITY, CALIFORNIA.

Effective September 1, 1999, the above-described Lease will be amended as
follows to provide for Tenant's expansion premises:

1.   Expansion Premises. Approximately 3,610 square feet of rentable area
     ------------------
     located on the third floor of the building known as 555 Twin Dolphin Drive.
     The Premises as expanded herein are approximately as shown outlined in red
     on the attached floor plan (Exhibit A, Suite 350 and Exhibit A-1, Suite
     600).

2.   Premises. The Premises of the Lease as defined per the Basic Lease
     --------
     Information shall be amended such that effective September 1, 1999, the
     square footage shall increase from 17,198 rentable square feet to 20,808
     rentable square feet.

3.   Rent. Base Rent for the Premises shall be as follows:
     ----

     9/1/99 - 10/31/99:   Sixty One Thousand Sixty Eight and 11/100ths dollars
                          ($61,068.11) per month plus Tenant's Proportionate
                          Share of Basic Operating Cost per Paragraph 29 of the
                          Lease. Tenant's Proportionate Share of Basic Operating
                          Cost through December 1999 is estimated to be
                          $17,719.11 per month. Tenant's Proportionate Share of
                          Basic Operating Cost is estimated a year in advance
                          and collected on a monthly basis. Any adjustments
                          necessary (up or down) will be made at the end of the
                          operating year.

     11/1/99 - 10/31/00:  Sixty Two Thousand Seven Hundred Eighty Seven and
                          91/100ths dollars ($62,787.91) per month plus Tenant's
                          Proportionate Share of Basic Operating Cost per
                          Paragraph 29 of the Lease. Tenant's Proportionate
                          Share of Basic Operating Cost through December 1999 is
                          estimated to be $17,719.11 per month. Tenant's
                          Proportionate Share of Basic Operating Cost is
                          estimated a year in advance and collected on a monthly
                          basis. Any adjustments necessary (up or down) will be
                          made at the end of the operating year.

     11/1/00 - 10/31/01:  Sixty Four Thousand Nine Hundred Five and 52/100ths
                          dollars ($64,905.52) per month plus Tenant's
                          Proportionate Share of Basic Operating Cost per
                          Paragraph 29 of the Lease

     11/1/01 - 10/31/02   Sixty Seven Thousand Thirty Seven and 05/100ths
                          dollars ($67,037.05) per month plus Tenant's
                          Proportionate Share of Basic Operating Cost per
                          Paragraph 29 of the Lease.

5.   Security Deposit. The Security Deposit, as set forth in the Basic Lease
     ----------------
     Information of the Lease shall be increased from $60,193.00 to $75,000.00.
     The increase ($14,807.00) to the Security Deposit shall be due and payable
     upon execution of this Expansion Agreement
<PAGE>

6.   Tenant's Proportionate Share. Tenant's Proportionate Share per the Basic
     ----------------------------
     Lease Information of the Lease shall increase effective September 1, 1999
     from 8.66% to 10.49%

7.   Tenant Improvements. Tenant agrees to accept the Premises as so expanded in
     -------------------
     "as is" condition except for the improvements as described on the attached
     Exhibit B.

All other terms and conditions of the Lease shall remain in full force and
effect and shall apply to the expansion premises as well as to the original
premises.

Dated:  6-22-99
        -------

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

Landlord: SPIEKER PROPERTIES, L.P.
By: Spieker Properties, Inc.

       /s/ Nancy B. Gille
       ------------------

      By:  Nancy B. Gille
           --------------
      Its: Vice President
           --------------
      Dated:  6/24/99
              -------

Tenant:  EXTRICITY SOFTWARE, INCORPORATED

By: /s/ [ILLEGIBLE]^^
    -------------------

Its: VP Finance and CFO
     ------------------

Dated:   6-22-99
         -------
<PAGE>

                                   EXHIBIT A

                                  THIRD FLOOR

                                    [GRAPH]
<PAGE>

                                  EXHIBIT A-1

                                  SIXTH FLOOR

                                    [GRAPH]
<PAGE>

                                   EXHIBIT B
                                   ---------
                            to Expansion Agreement

Landlord, at Landlord's sole cost and expense, shall perform or cause to be
performed the following improvements to the Premises:

1.  Re-paint all interior walls; color selection by Tenant

2.  Steam clean carpeted area and clean/buff tiled area.
<PAGE>

555 Twin Dolphin Drive
Suite 110
Redwood City, CA 94065
(415) 591-1717
Fax (415) 591-9502
                                                                [SPIEKER
LEASE COMMENCEMENT (START-UP) LETTER                            PROPERTIES LOGO]


October 7, 1999

Karin Duff
Extricity Software. Inc.
555 Twin Dolphin Drive, Suite 600
Redwood City, Ca 94065


     Re:  Lease for Premises at 555 Twin Dolphin Drive, Redwood City, California
(the "Lease,")

Dear Karin:

Per Paragraph 3 of the Lease dated March 28, 1997, this letter Will serve to
define the term of the Expansion Agreement dated June 22, 1999, as beginning
September 13, 1999, and ending on October 31, 2002.

Per paragraph 5 of the Expansion Agreement, please remit $14,807.00 for the
increase of the security deposit.

Please amend the Letter of Credit No SB20011412, dated November 5, 1997 to
reflect the name Extricity Software, Inc..

Please indicate your acceptance of this by signing where indicated below and
returning all three (3) copies of this letter to our office. We will return a
fully executed copy to you for your files.

Your full obligations is now due and payable, broken down as follows:

       Increase in Security Deposit                           14,807.00
       Base Rent, Ste. 350-September 13-30                     6,819.53
       Est. Operating Expenses, Ste 350- September 13-30       1,844.47
       Base Rent, Ste. 650-September                          49,702.22
       Est. Operating Expenses, Ste 650- September            14,645.00
       Base Rent, Sts. 350&650-October                        61,068.11
       Estimated Operating Expenses Sts. 350&650-October      17,719.l1
                                                           ------------
       total:                                                166,605.44
       Received:                                            (144,574.00)
       Total Outstanding:                                  $  22,031.44
                                                           ============
<PAGE>

October 7, 1999
Karin Duff
Extricity Software, Inc.
Page 2

As a reminder, you will not be invoiced for rent. Please notify your accounting
department that rent is due and payable on or before the first of each month.
Please reference your Lease Id # (EXTRSOF01) on all checks sent to Spieker
Properties. All checks should be made payable to Spieker Properties and mailed
                                                 ------------------
to the following address:

Spieker Properties
P.O. Box 45587
Department 11511
San Francisco, California 94145-0587

Please make a note that as of November 1, 1999, a rent increase will take place
per your Lease and your monthly rental obligation will total $80,507.02
($62,787.91 base rent, $17,719.11 for operating expenses).

Please furnish this office with current evidence of the insurance coverage
required to be maintained by Tenant pursuant to Paragraph 11.E of the Lease,
and, naming Spieker Properties, L.P., as an additional insured.

It is truly a pleasure having Extricity Software, Inc. as a Tenant at the
Project and we wish you every success at your new location.

Should you have any questions or require any additional information, please feel
free to call me at (650) 591-1717.

Sincerely,

/s/ Anne Risberg

Anne Risberg
Project Manager

AGREED AND ACCEPTED:

Spieker Properties, L.P.,                      Extricity Software, Inc.
a California limited partnership

By:  Spieker Properties, Inc.,
     a Maryland corporation
     its general partner

                                               By:  /s/ [ILLEGIBLE]^^
                                                    ----------------------------
                                               Its: ____________________________

     By:   /s/ [ILLEGIBLE]^^
          ---------------------------
     Its:        10/18/99
          --------------------------
                                               Approved as to Legal Fee

                                               Signed: [ILLEGIBLE]^^
                                                      ------------------
                                               Date:     10-11-99
                                                    --------------------
<PAGE>

                                 AMENDMENT #3
                                 ------------

                              EXPANSION AGREEMENT
                              -------------------

AMENDMENT NUMBER 3 TO THAT LEASE DATED MARCH 28,1997 AND AS AMENDED BY LEASE
AMENDMENT #1 DATED OCTOBER 6, 1997 AND AMENDMENT NUMBER 2 EFFECTIVE SEPTEMBER 1,
1999 BETWEEN SPIEKER PROPERTIES, L.P., AS LANDLORD, AND EXTRICITY SOFTWARE,
INC., FORMERLY CROSSROUTE SOFTWARE, INCORPORATED, AS TENANT, FOR PREMISES
LOCATED AT 555 TWIN DOLPHIN DRIVE, REDWOOD CITY, CALIFORNIA.

Effective January 1, 2000, the above-described Lease will be amended as follows
to provide for Tenant's second expansion premises (the "Second Expansion
Premises"):

1.   Date of Agreement. The date of this Amendment Number 3 shall be December
     -----------------
     28, 1999.

2.   Second Expansion Premises. Approximately 5,255 square feet of rentable area
     -------------------------
     located on the first floor of the building known as 555 Twin Dolphin Drive
     as shown outlined in red on the attached floor plan (Exhibit A - Suite
     180).

3.   Premises. The Premises of the Lease as defined per the Basic Lease
     --------
     Information shall be amended such that effective January 1, 2000, the
     square footage shall increase from 20,808 rentable square feet to 26,063
     rentable square feet. The Premises as expanded herein are approximately as
     shown outlined in red on the attached floor plan (Exhibit A - Suite 180
     (Second Expansion Premises), Exhibit A-l, Suite 350 ("Expansion Premises")
     and Exhibit A-2, Suite 600 ("Original Premises") collectively, the
     Premises.

4.   Term for Second Expansion Premises. The Term for the Second Expansion
     ----------------------------------
     Premises shall be sixty (60) months commencing January 1, 2000.

5.   Rent. Rent for the Second Expansion Premises shall be as follows:
     ----

     1/1/2000-12/31/2000:     Nineteen Thousand Four Hundred Sixty Six and
                              00/100ths dollars ($19,466.00) per month plus
                              Basic Operating Cost per Paragraph 29 of the
                              Lease. Operating expenses through December 2000
                              are estimated to be $4,707.00 per month. Direct
                              operating expenses are estimated a year in advance
                              and collected on a monthly basis. Any adjustments
                              necessary (up or down) will be made at the end of
                              the operating year.

     1/1/2001-12/31/2001:     Twenty Thousand One Hundred Forty Seven and
                              00/100ths dollars ($20,147.00) per month per month
                              plus Basic Operating Cost per Paragraph 29 of the
                              Lease.
<PAGE>

     1/1/2002-12/31/2002:     Twenty Thousand Eight Hundred Fifty Two and
                              00/100ths dollars ($20,852.00) per month per month
                              plus Basic Operating Cost per Paragraph 29 of the
                              Lease.

     1/1/2003-12/31/2003:     Twenty One Thousand Eight Hundred Fifty Two and
                              00/100ths dollars ($21,582.00) per month per month
                              plus Basic Operating Cost per Paragraph 29 of the
                              Lease.

     1/1/2004-12/31/2004:     Twenty Two Thousand Three Hundred Thirty Seven and
                              00/100ths dollars ($22,337.00) per month per month
                              plus Basic Operating Cost per Paragraph 29 of the
                              Lease.

                              Rent for the Expansion Premises and the Original
                              Premises shall remain as enumerated in Amendment
                              Number 2 and shall not in any way be amended,
                              modified or altered by this Amendment Number 3.

6.   Security Deposit.        Three hundred thousand and 00/100 dollars
     ----------------         ($300,000.00) in the form of a letter of credit
                              pursuant to the below-itemized terms.

     A.   (i) Delivery of Letter of Credit. In addition to the existing Security
          Deposit currently held by Landlord, Tenant shall, on execution of this
          Amendment Number 3, deliver to Landlord and cause to be in effect
          during the Lease Term for the Second Expansion Premises an
          unconditional, irrevocable letter of credit ("LOC") in the amount
          specified above. The LOC shall be in a form acceptable to Landlord and
          shall be issued by an LOC bank selected by Tenant and acceptable to
          Landlord. An LOC bank is a bank that accepts deposits, maintains
          accounts, has a local office that will negotiate a letter of credit,
          and the deposits of which are insured by the Federal Deposit Insurance
          Corporation. Tenant shall pay all expenses, points, or fees incurred
          by Tenant in obtaining the LOC. The LOC shall not be mortgaged,
          assigned or encumbered in any manner whatsoever by Tenant without the
          prior written consent of Landlord. Tenant acknowledges that Landlord
          has the right to transfer or mortgage its interest in the Project, the
          Building and in this Lease and Tenant agrees that in the event of any
          such transfer or mortgage, Landlord shall have the right to transfer
          or assign the LOC and/or the LOC Security Deposit (as defined below)
          to the transferee or mortgagee, and in the event of such transfer,
          Tenant shall look solely to such transferee or mortgagee for the
          return of the LOC and/or the LOC Security Deposit.

          (ii) Replacement of Letter of Credit. Tenant may, from time to time,
          replace any existing LOC with a new LOC if the new LOC (a) becomes
          effective at least thirty (30) days before expiration of the LOC that
          it replaces; (b) is in the required LOC amount; (c) is issued by an
          LOC bank acceptable to Landlord; and (d) otherwise complies with the
          requirements of this Paragraph 6 A.

          (iii) Landlord's Right to Draw on Letter of Credit. Landlord shall
          hold the LOC as security for the performance of Tenant's obligations
          under the Lease. If, after notice and failure to cure within any
          applicable period provided in this Lease, Tenant defaults on any
          provision of the Lease, Landlord may, without prejudice to any other
          remedy it has, draw on that portion of the LOC necessary to (a) pay
          Rent or other sum in default; (b) pay or reimburse Landlord for any
          amount that Landlord may spend or become obligated
<PAGE>

          to spend in exercising Landlord's rights under Paragraph 25 (Right of
          Landlord to Perform); and/or (c) compensate Landlord for any expense,
          loss, or damage that Landlord may suffer because of Tenant's default.
          If Tenant fails to renew or replace the LOC at least thirty (30) days
          before its expiration, Landlord may, without prejudice to any other
          remedy it has, draw on the entire amount of the LOC.

     B.   LOC Security Deposit. Any amount of the LOC that is drawn on by
          Landlord but not applied by Landlord shall be held by Landlord as a
          security deposit (the "LOC Security Deposit") in accordance with
          Paragraph 15 of the Lease.

     C.   Restoration of Letter of Credit and LOC Security Deposit. If Landlord
          draws on any portion of the LOC and/or applies all or any portion of
          such draw, Tenant shall, within five (5) business days after demand by
          Landlord, either (a) deposit cash with Landlord in an amount that,
          when added to the amount remaining under the LOC and the amount of any
          LOC Security Deposit, shall equal the LOC Amount then required under
          this Amendment Number 3; or (b) reinstate the LOC to the full LOC
          Amount.

7.   Tenant's Proportionate Share. Tenant's Proportionate Share per the Basic
     ----------------------------
     Lease Information of the Lease shall increase effective January 1, 2000
     from 10.49% to 13.14%. Upon the expiration or earlier termination of the
     Term for the Original Premises and the Expansion Premises, Tenant's
     proportionate share shall be reduced to 2.65%

8.   Tenant Improvements. Tenant agrees to accept the Second Expansion Premises
     -------------------
     as so expanded in "as is" condition.

All other terms and conditions of the Lease shall remain in full force and
effect and shall apply to the Second Expansion Premises as well as to the
Expansion Premises and the Original Premises. IN WITNESS WHEREOF, the parties
hereto have executed this Amendment Number 3 as of the Date of Agreement above
written.

Landlord: SPIEKER PROPERTIES, L.P.
By: Spieker Properties, Inc.

       /s/ Nancy B. Gille
     ----------------------

     By:  Nancy B. Gille
     Its:  Vice President

     Dated:  2/8/00
             ----------


Tenant:  EXTRICITY SOFTWARE, INC.

By: /s/ Stephan Albertolle
    -----------------------

Printed: Stephan Albertolle
         ------------------

Its: CFO
     ----------------------

Dated:_____________________