FIRST AMENDMENT TO OFFICE LEASE AGREEMENT

THIS FIRST AMENDMENT TO OFFICE LEASE AGREEMENT (this
"Amendment") is executed as of December 21, 2001, by and between
WEO-CONCAR, LLC, a California limited liability company, formerly known as
Office Opportunity Associates, LLC, a California limited liability company
("Landlord"), and SIEBEL SYSTEMS, INC., a Delaware corporation
("Tenant").

Recitals

1. Landlord and Tenant are parties to that certain Office Lease Agreement,
    dated as of September 14, 2000, as modified by that certain letter agreement
    dated March 8, 2001 (as so modified, the "Original Lease"). Pursuant
    to the Original Lease, Landlord has agreed to construct the Project and
    Tenant has agreed to lease from Landlord all of the rentable square feet of
    office space in the Project. The Project is expected to consist of two
    office buildings of approximately 217,018 total rentable square feet, a
    retail building of approximately 2,200 rentable square feet that will be for
    retail use for another tenant(s), and a parking garage. The foregoing shall
    not limit or modify the provisions of Section II of the Lease providing
    for remeasurement of the Premises and Buildings upon completion of the
    Building Shells. Capitalized terms not defined in this Amendment shall have
    the meanings given them in the Original Lease. As used in this Amendment,
    "Lease" shall mean the Original Lease, as amended by this Amendment.
2. As part of the Original Lease, Tenant approved a set of Building Shell
    specifications set forth in Exhibit D-2 thereof. Landlord previously has
    exchanged with Tenant various draft construction drawings for the Building
    Shell for Tenant's review and to allow Tenant to begin to prepare the Space
    Plans, and thereafter has sent Tenant final construction documents for the
    Building Shell ("Building Shell CD's"). Landlord also has obtained
    the required building permits for construction of the Building Shell from
    the City of San Mateo ("City"). Landlord has hired Webcor
    Construction, Inc., dba Webcor Builders ("Webcor") as the general
    contractor for the Building Shell, and as of the Effective Date, Webcor has
    commenced construction of the parking structure and the Buildings.
3. In the process of reviewing the draft Building Shell CD's, Tenant
    determined that there are certain changes and additions to the Building
    Shell that Tenant would like to have incorporated therein. Landlord is
    willing to accommodate Tenant's desires to incorporate such changes, subject
    to the terms and conditions of this Amendment.
4. Landlord and Tenant desire to amend the Original Lease (i) to make
    certain changes and additions to the Building Shell and any changes to the
    Tenant Improvements resulting therefrom, (ii) to set forth Tenant's
    obligations to pay agreed upon costs in connection with such changes and
    additions, and (iii) to otherwise provide for all impacts that such changes
    and additions may have on the Original Lease and the economic terms thereof,
    all upon and subject to the terms and conditions set forth in this
Amendment.

NOW THEREFORE, in consideration of, and incorporating, the
foregoing recitals and the mutual agreements of the parties herein, Landlord and
Tenant hereby agree as follows:

1. Changes and Additions to Building Shell.
    
    Tenant hereby requests Landlord make and incorporate those changes and
      additions to the Building Shell which are set forth in Attachment A
      hereto ("Building Shell Changes"), which Building Shell Changes
      Landlord hereby approves and agrees to incorporate into the Buildings
      pursuant to the provisions of this Amendment. The costs to be charged to
      Tenant in connection with such Building Shell Changes shall be the
      Estimated Costs set forth on Attachment A("Tenant's Shell
      Costs"),together with reasonable design and architectural fees
      incurred by Landlord in connection with the Building Shell Changes, which
      fees have been approved by Tenant, which approval shall not be
      unreasonably withheld ("Design Costs"). In addition to Tenant's
      Shell Costs and Design Costs, Tenant shall pay to Landlord a development
      and construction management fee ("Landlord's Overhead") equal to
      five percent (5%) of Tenant's Shell Costs.Tenant acknowledges that the Building Shell Changes do not constitute
      and are not being sought as Warm Shell Construction Item changes to the
      Building Shell pursuant to Section 9 of Exhibit D
      (Construction Rider) to the Original Lease. Tenant acknowledges that the
      date for exercising its rights for the Warm Shell Construction Items under
      said Section 9 has passed and Tenant hereby waives and releases all
      its rights under said Section 9.Landlord and Tenant acknowledge and agree that no Tenant Delay shall
      be deemed to have occurred as a result of the Building Shell Changes,
      including as a result of any preparation or modification of building plans
      and drawings, cost estimates, construction contracts or change orders, or
      as a result of Landlord's construction of such Building Shell Changes.
2. Tenant hereby requests Landlord make and incorporate those changes and
      additions to the Building Shell which are set forth in Attachment A
      hereto ("Building Shell Changes"), which Building Shell Changes
      Landlord hereby approves and agrees to incorporate into the Buildings
      pursuant to the provisions of this Amendment. The costs to be charged to
      Tenant in connection with such Building Shell Changes shall be the
      Estimated Costs set forth on Attachment A("Tenant's Shell
      Costs"),together with reasonable design and architectural fees
      incurred by Landlord in connection with the Building Shell Changes, which
      fees have been approved by Tenant, which approval shall not be
      unreasonably withheld ("Design Costs"). In addition to Tenant's
      Shell Costs and Design Costs, Tenant shall pay to Landlord a development
      and construction management fee ("Landlord's Overhead") equal to
      five percent (5%) of Tenant's Shell Costs.
3. Tenant acknowledges that the Building Shell Changes do not constitute
      and are not being sought as Warm Shell Construction Item changes to the
      Building Shell pursuant to Section 9 of Exhibit D
      (Construction Rider) to the Original Lease. Tenant acknowledges that the
      date for exercising its rights for the Warm Shell Construction Items under
      said Section 9 has passed and Tenant hereby waives and releases all
      its rights under said Section 9.
4. Landlord and Tenant acknowledge and agree that no Tenant Delay shall
      be deemed to have occurred as a result of the Building Shell Changes,
      including as a result of any preparation or modification of building plans
      and drawings, cost estimates, construction contracts or change orders, or
      as a result of Landlord's construction of such Building Shell Changes.
5. Application of the Tenant Improvement Allowance to Tenant's Shell
    Costs. Landlord agrees to pay for the costs of constructing the Building
    Shell Changes, and for the Design Costs and Landlord's Overhead, as an
    offset against the Tenant Improvement Allowance, and that therefore the
    Tenant Improvement Allowance will be reduced by Tenant's Shell Costs, the
    Design Costs and Landlord's Overhead.
6. Required Removables. Landlord has indicated on Attachment A
    which of the Building Shell Changes will need to be removed upon the
    expiration or earlier termination of the Lease, and therefore, same shall
    constitute Required Removables under the Lease. Landlord's approval of any
    Changes to the Tenant Improvements resulting from Building Shell Changes may
    be conditioned upon Tenant's agreement to remove any particular items
    thereof which are expressly so identified by Landlord as a Required
    Removable at the time Landlord finally and formally approves such Change.
    All such Required Removables shall be removed and the Property restored in
    connection with said removal, in the same manner as required of Tenant with
    respect to all other Required Removables pursuant to all applicable
    provisions of the Lease, including, without limitation, Sections VIII and
    XXX of the Original Lease. Notwithstanding the foregoing, although
    Attachment A indicates that the Building Shell Changes listed as items 56,
    61, 64, 100 and 101 are Required Removables, Tenant will not be required to
    remove any below-grade piping or conduit that are part of such items, but
    shall be required to remove all above grade-elements, such as piping,
    conduit and fixtures and to cap any piping or conduit flush with slabs or
    ground surface.
7. Base Rent During Pre-Term Period. Tenant agrees to pay to Landlord
    Base Rent for each floor of the Premises for which the Rent Commencement
    Date has occurred from the Rent Commencement Date therefor until the
    Commencement Date of the Lease at the same rate per rentable square foot of
    the Premises as is applicable to the Premises for Months 1-12 as set forth
    in the Basic Lease Information.
8. Letter of Credit.
    
    Tenant has previously delivered to Landlord the sum of One Million One
      Hundred Ninety-Nine Thousand Two Hundred and Fifty Dollars
      ($1,199,250.00), which represents the estimated first month's Base Rent.
      Concurrently with its execution of this Amendment, Tenant shall deliver to
      Landlord a clean, unconditional, irrevocable, transferable standby letter
      of credit (the "Letter of Credit"), naming Landlord as beneficiary,
      in the form of Attachment B to this Amendment, and issued by a
      financial institution, satisfactory to Landlord. The amount available to
      be drawn under the Letter of Credit shall be One Million One Hundred
      Ninety-Nine Thousand Two Hundred and Fifty Dollars ($1,199,250.00).
      Provided that Tenant has delivered the Letter of Credit to Landlord,
      Landlord shall return to Tenant, within five (5) days after the execution
      of this Amendment, the full amount of the Prepaid Rent, as defined in
      Section I.H of the Basic Lease Information.Landlord shall hold the Letter of Credit in support of Tenant's
      obligations under the Lease, including damages that may accrue after a
      termination of the Lease under California Civil Code Section 1951.2.
      Tenant expressly waives the provisions of California Civil Code Section
      1950.7 with respect to the Letter of Credit. Landlord shall be entitled to
      draw any portion or the entire amount under the Letter of Credit upon
      notice that the Letter of Credit will not be renewed or will be terminated
      or upon default by Tenant, provided that Landlord shall not be obligated
      to give Tenant notice or opportunity to cure prior to drawing on the
      Letter of Credit. Landlord may apply such amounts drawn to satisfy
      Tenant's obligations under the Lease (in such order as Landlord may
      elect). The Letter of Credit shall provide for partial draws by Landlord.
      To the extent the Letter of Credit or the amounts drawn thereunder have
      not been previously applied against Tenant's other obligations under the
      Lease, Landlord shall be entitled to make draws from the Letter of Credit
      and apply it against the Base Rent as it comes due, provided, however,
      that if Tenant pays all such Base Rent in cash at or before the time such
      Base Rent comes due, Landlord shall return the Letter of Credit (including
      any unapplied amounts drawn against the Letter of Credit by Landlord) to
      Tenant, together with such instructions and documentation as the issuer of
      the Letter of Credit may require to cancel the same, within five (5) days
      after the first date on which Landlord has received payments of Base Rent
      from Tenant (exclusive of any Base Rent paid during the
      period described in Paragraph 4) in the aggregate amount of at least
      One Million One Hundred Ninety-Nine Thousand Two Hundred and Fifty Dollars
      ($1,199,250.00).Tenant shall not assign or encumber or attempt to assign or encumber
      the Letter of Credit and neither Landlord nor its successors or assigns
      shall be bound by any such assignment or encumbrance or attempted
      assignment or encumbrance.In the event of a financing, sale or other transfer of the Building,
      Tenant, if requested by Landlord in writing, at its sole cost and expense
      within ten (10) Business Days after receiving such request, will cause the
      issuing bank of the Letter of Credit to consent to the assignment or to
      issue a substitute letter of credit on identical terms to the Letter of
      Credit, other than the stated beneficiary, from the same issuing bank or,
      if the lender or transferee so requests, from another bank acceptable to
      such lender or transferee in its reasonable discretion, naming such lender
      or transferee as the beneficiary thereof, upon delivery by Landlord of the
      then outstanding Letter of Credit.
9. Tenant has previously delivered to Landlord the sum of One Million One
      Hundred Ninety-Nine Thousand Two Hundred and Fifty Dollars
      ($1,199,250.00), which represents the estimated first month's Base Rent.
      Concurrently with its execution of this Amendment, Tenant shall deliver to
      Landlord a clean, unconditional, irrevocable, transferable standby letter
      of credit (the "Letter of Credit"), naming Landlord as beneficiary,
      in the form of Attachment B to this Amendment, and issued by a
      financial institution, satisfactory to Landlord. The amount available to
      be drawn under the Letter of Credit shall be One Million One Hundred
      Ninety-Nine Thousand Two Hundred and Fifty Dollars ($1,199,250.00).
      Provided that Tenant has delivered the Letter of Credit to Landlord,
      Landlord shall return to Tenant, within five (5) days after the execution
      of this Amendment, the full amount of the Prepaid Rent, as defined in
      Section I.H of the Basic Lease Information.
10. Landlord shall hold the Letter of Credit in support of Tenant's
      obligations under the Lease, including damages that may accrue after a
      termination of the Lease under California Civil Code Section 1951.2.
      Tenant expressly waives the provisions of California Civil Code Section
      1950.7 with respect to the Letter of Credit. Landlord shall be entitled to
      draw any portion or the entire amount under the Letter of Credit upon
      notice that the Letter of Credit will not be renewed or will be terminated
      or upon default by Tenant, provided that Landlord shall not be obligated
      to give Tenant notice or opportunity to cure prior to drawing on the
      Letter of Credit. Landlord may apply such amounts drawn to satisfy
      Tenant's obligations under the Lease (in such order as Landlord may
      elect). The Letter of Credit shall provide for partial draws by Landlord.
      To the extent the Letter of Credit or the amounts drawn thereunder have
      not been previously applied against Tenant's other obligations under the
      Lease, Landlord shall be entitled to make draws from the Letter of Credit
      and apply it against the Base Rent as it comes due, provided, however,
      that if Tenant pays all such Base Rent in cash at or before the time such
      Base Rent comes due, Landlord shall return the Letter of Credit (including
      any unapplied amounts drawn against the Letter of Credit by Landlord) to
      Tenant, together with such instructions and documentation as the issuer of
      the Letter of Credit may require to cancel the same, within five (5) days
      after the first date on which Landlord has received payments of Base Rent
      from Tenant (exclusive of any Base Rent paid during the
      period described in Paragraph 4) in the aggregate amount of at least
      One Million One Hundred Ninety-Nine Thousand Two Hundred and Fifty Dollars
      ($1,199,250.00).
11. Tenant shall not assign or encumber or attempt to assign or encumber
      the Letter of Credit and neither Landlord nor its successors or assigns
      shall be bound by any such assignment or encumbrance or attempted
      assignment or encumbrance.
12. In the event of a financing, sale or other transfer of the Building,
      Tenant, if requested by Landlord in writing, at its sole cost and expense
      within ten (10) Business Days after receiving such request, will cause the
      issuing bank of the Letter of Credit to consent to the assignment or to
      issue a substitute letter of credit on identical terms to the Letter of
      Credit, other than the stated beneficiary, from the same issuing bank or,
      if the lender or transferee so requests, from another bank acceptable to
      such lender or transferee in its reasonable discretion, naming such lender
      or transferee as the beneficiary thereof, upon delivery by Landlord of the
      then outstanding Letter of Credit.
13. Entire Agreement. All attachments, exhibits and addenda attached
    hereto are incorporated into this Amendment. This Amendment, together with
    the Original Lease, contains the entire agreement of the parties hereto with
    respect to the subject matter hereof and may not be changed or terminated
    orally or by course of conduct.
14. Counterparts. This Amendment may be executed in counterparts, each
    of which shall be deemed an original as against the party whose signature is
    affixed thereto, and all of which together shall constitute but one and the
    same agreement.
15. Reaffirmation of Lease. Except as specifically set forth in this
    Amendment, the Original Lease remains unchanged and, as modified by this
    Amendment, is in full force and effect. This Amendment shall be binding upon
    and inure to the benefit to the parties and their respective successors and
    assigns. All references in the Original Lease to "this Lease" shall mean the
    Original Lease as amended by this Amendment.
    IN WITNESS WHEREOF, Landlord and Tenant have entered
    into and executed this Amendment as of the Effective Date.

TO: Bank of America, N.A.



We request you to transfer all of our rights as beneficiary
  under the Letter of Credit referenced above to the new beneficiary named
  below:



_________________________________________________________NAME
  OF NEW BENEFICIARY

_________________________________________________________ADDRESS



By this transfer, all our rights as the original beneficiary,
  including all rights to make drawings under the Letter of Credit, go to the
  new beneficiary. The new beneficiary shall have sole rights as beneficiary,
  whether existing now or in the future, including sole rights to agree to any
  amendments, including increases or extensions or other changes. All amendments
  will be sent directly to the new beneficiary without the necessity of consent
  by or notice to us.

We enclose the original letter of credit and any amendments.
  Please indicate your acceptance of our request for the transfer by endorsing
  the letter of credit and send it to the new beneficiary with your customary
  notice of transfer.

The Applicant is responsible for the transfer fee.



|The signature and title at the right conform
        withthose shown in our files as authorized to sign for the
        beneficiary. Policies governing signatureauthorization as required
        for withdrawals fromcustomer accounts shall also be applied to the
        authorization of signatures on this
        form.______________________________________NAME OF
        BANK_______________________________________AUTHORIZED
        SIGNATURE AND TITLE |  | _______________________________________________NAME
        OF BENEFICIARY
        _______________________________________________NAME
        OF AUTHORIZED SIGNER AND TITLE
        
        _______________________________________________AUTHORIZED
        SIGNATURE
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

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SECOND AMENDMENT TO OFFICE LEASE AGREEMENT



THIS SECOND AMENDMENT TO OFFICE LEASE AGREEMENT (this
  "Amendment") is executed as of September 25, 2002, by and between
  WEO - CONCAR, LLC, a California limited liability company, formerly known as
  Office Opportunity Associates, LLC, a California limited liability company
  ("Landlord"), and SIEBEL SYSTEMS, INC., a Delaware corporation
  ("Tenant").

Recitals



1. Landlord and Tenant are parties to that certain Office Lease
      Agreement, dated as of September, 2000 (the "Original Lease"), as
      modified by that certain letter agreement dated March 8, 2001, and First
      Amendment to Office Lease Agreement dated December 21, 2001 (the "First
      Amendment"). (The Original Lease as so modified is called the
      "Existing Lease"). Pursuant to the Original Lease, Landlord has
      agreed to construct the Project and Tenant has agreed to lease from
      Landlord all of the rentable square feet of office space in the Project.
      The Project is expected to consist of the following in San Mateo,
      California: an office building ("Building 1") located at 900 Concar
      Drive containing approximately 116,592 rentable square feet, an office
      building ("Building 2") located at 800 Concar Drive, containing
      approximately 100,526 rentable square feet, a retail building of
      approximately 2,200 rentable square feet that will be for retail use for
      another tenant(s), and a parking garage. The foregoing shall not limit or
      modify the provisions of Section II of the Lease providing for
      remeasurement of the Premises and Buildings upon completion of the
      Building Shells. Capitalized terms not defined in this Amendment shall
      have the meanings given them in the Existing Lease. As used in this
      Amendment, "Lease" shall mean the Existing Lease, as amended by
      this Amendment.
2. Tenant and Landlord wish to amend the Lease, inter alia,
      (i) to provide that Tenant and not Landlord shall be obligated to
      construct the Tenant Improvements, (ii) to change the definition of
      Landlord Work to be performed by Landlord and the completion dates for
      Landlord Work, (iii) to eliminate the Tenant Improvement Allowance,
      (iv) to reduce Base Rent, and (v) to provide certain other
      changes to the Existing Lease, all on the following terms and conditions:



NOW THEREFORE, in consideration of, and incorporating,
  the foregoing recitals and the mutual agreements of the parties herein,
  Landlord and Tenant hereby agree as follows:

1. Elimination of Tenant Improvement Allowance. The Tenant
      Improvement Allowance is changed to zero dollars ($0.00).
2. Modification of Landlord Work. The term "Landlord Work" shall be
      changed to mean the development, design and construction of the Project
      and Building Shell, but not the Tenant Improvements. The Building Shell
      shall substantially conform with the specifications described in Paragraph
      A of Exhibit D-2 of the Lease except as follows: (i) that portion of
      Item 3.4 thereof described as "perimeter walls taped and sanded,
      ready for tenant finish" (the "Perimeter Tape Work") is hereby eliminated,
      (ii) the ground floor of Building 1 (but not of Building 2) will
      include one men's and women's restroom as described in Item 3.1 of
      Paragraph A of Exhibit D-2 (the "Building 1 Restroom"), and
      (iii) the Building Shell Changes will be incorporated into the
      Building Shell. Landlord shall Substantially Complete the Landlord Work no
      later than December 31, 2002, except to the extent that any delay in such
      Substantial Completion is a result of a Tenant Delay. As provided in the
      second paragraph of Section III.A of the Lease,



















D. "Base Rent"



|Months 1 - 12Months 13 - 24Months 25 -
            36Months 37 - 48Months 49 - 60Months 61 - 72Months
            73 - 84Months 85 - 96Months 97 - 108Months 109 -
            120Months 121 - 132Months 133 - 144Months 145 -
            156 |  | $5.63 per rentable square foot per month$5.83
            per rentable square foot per month$6.04 per rentable square foot
            per month$6.26 per rentable square foot per month$6.49 per
            rentable square foot per month$6.73 per rentable square foot per
            month$6.97 per rentable square foot per month$7.19 per
            rentable square foot per month$7.41 per rentable square foot per
            month$7.64 per rentable square foot per month$7.88 per
            rentable square foot per month$8.12 per rentable square foot per
            month$8.37 per rentable square foot per
        month
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------





















|LANDLORD:
        WEO - CONCAR, LLC,a California limited
        liability company
        
        By: Wilson/Equity Office, LLCa Delaware limited
        liability companyits Manager
        
        By: Wilson Investors-California, LLCa Delaware
        limited liability companyits Manager
        
        By:/s/ Thomas P. SullivanThomas P.
        Sullivan, Manager | TENANT:
        SIEBEL SYSTEMS, INC.,a Delaware corporation
        
        By: /s/ Craig StevensName: Craig
        StevensTitle: Director, Legal Affairs
        
        
        
        By: Name: Title:
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

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EXHIBIT A

Costs to be Reimbursed by Tenant



|Tenant's Shell Costs under Amendment 1 | $ 823,344 
|-------------------------------------- | ----------
|Landlord's Overhead under Amendment 1  | 37,984    
|Accrued Design Costs through 9/25/02   | 222,596   
|Credit for Perimeter Tape Work         | <73,289>  
|Bathroom on Ground Floor               | 50,000    
|Conduit from Emergency Generator       | 49,451    
|Total as of date of Amendment 2:       | $1,110,086

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September 19, 2002



Ms. Linda Jansen
Vice President, Real Estate and Facilities
Siebel Systems, Inc.
2207 Bridgepoint Parkway
San Mateo. CA 94404



Siebel Systems, Inc.
Attn:	General Counsel
2207 Bridgepoint Parkway
San Mateo, CA 94404



Re: 			Concar - Office Lease Agreement, dated as of September 2000 by and between WEO CONCAR, LLC, a California limited liability company, formerly known as Office Opportunity Associates, LLC, a California limited liability company ("Landlord"), and SIEBEL SYSTEMS, INC., a Delaware corporation ("Tenant"), as modified by that certain letter agreement dated March 8, 2001, and First Amendment to Office Lease Agreement dated December 21, 2001 (such lease with all such amendments, the "Lease")



Ladies and Gentlemen:



This letter concerns your commencement of construction of tenant improvements in the Buildings 1 and 2 at the Concar project in San Mateo. (All capitalized terms used in this letter will have the meanings given in the Lease.)



We were very pleased to learn recently you reversed your plans to leave the Buildings unoccupied for the time being, and now want to complete your tenant improvements and move in as quickly as possible. We have been working very hard with you and the City to help you achieve this goal, and we certainly intend to continue cooperating in this effort as much as we can. As I am sure you understand there are certain details that need to be attended to prior to your continuation of the tenant improvement construction so as not to expose the Landlord or Tenant to undue risks, liabilities or other problems.



As of last week, Venture Builders has instructed their subcontractors to cease work until Landlord has formally released them to proceed. Landlord is prepared to do so in accordance with the current tenant improvement schedule. However, we ask that you acknowledge your agreement to abide by the terms of this letter and the Lease and by the following terms by signing the enclosed copy of this letter and returning it to Landlord:

1. You are the party contracting for and responsible for supervising, managing and paying for all tenant improvement work being performed by Venture Builders and its subcontractors.

2. You indemnify us and hold us harmless from and against any and all loss, cost, damage, expense or liability, including reasonable attorneys' fees and costs related to or arising out of the prior or future construction of the tenant improvements, including, without limitation, any liens resulting from your work and any delay in completion of our work directly or indirectly caused by your or your contractors', representatives' or agents' construction or other activities at the Premises.

We hope that these matters can be resolved quickly, so that you can finish your work and commence occupancy of the Premises as soon as possible.

Thank you for your cooperation.

Very truly yours,

WEO CONCAR. LLC., a California limited liability company

By:	Wilson/Equity Office, LLC, a Delaware limited liability company
its Manager

By:	Wilson Investors-California, LLC, a Delaware limited liability company
its Manager

By: 	/s/ Thomas P. Sullivan
Thomas P. Sullivan, Manager



The undersigned acknowledges and agrees to the terms and provisions of this letter.

SIEBEL SYSTEMS, INC.A Delaware corporation
By: /s/ Linda S. Jansen
Name: Linda S. Jansen
Title: Vice President Facilities and Real Estate
Date: 9/26/02

cc: 		Bob Winter, EOP
Susan Sagy, EOP
Jeff Arnold, EOP
Mike Sanford, EOP
Jacqueline Moore
Jon Knorpp
Genelle Osendorf
Ken Morrison, The Rockridge Group