10600 North De Anza Blvd.	408.446.0700
	Suite 200	Facsimile 408.446.0583
	Cupertino, CA 95014-2075	www sobrato.com





DEVELOPMENT COMPANIES



FIRST AMENDMENT TO LEASE

Building 2 - 2211 Bridgepointe Parkway, San Mateo

This first amendment to lease (`Amendment') is made this
11th day of June, 1999 (the "Effective Date") by and
between SOBRATO INTERESTS III, a California limited partnership having an
address at I0600 N. De Anza Blvd Suite 200, Cupertino, California 95014
("Landlord") and SIEBEL SYSTEMS, INC., a Delaware corporation having
its principal place of business at 1855 South Grant Street, San Mateo,
California 94402 ("Tenant").

WITNESSETH

WHEREAS Landlord and Tenant entered to a lease dated
March 11, 1999, (the "Lease") for a building to be constructed at 2211
Bridgepointe Parkway in the location labeled as Building 2 on Exhibit
"A" attached hereto ("Premises"); and



WHEREAS Landlord and Tenant are concurrently entering
to a lease for Building 3 (the "Building 3 Lease"), the parties desire
to eliminate the option to lease Building 3 contained in the Lease; and



WHEREAS Landlord and Tenant wish to modify the
security deposit provisions to provide for individual letters of credit for this
Lease, the Building 1 Lease and the Building 3 Lease;



NOW, THEREFORE, in order to effect the intent of the
parties as set forth above and for good and valuable consideration exchanged
between the parties, the Lease is a ended as of the Effective Date as
follows



1.	The first sentence of Section 4.A is modified to
provide that the Lease Term shall be automatically extended so as to be
coterminous with the Expiration Date of the Building 3 Lease.  Rent during such
extended term shall be at the Base Monthly Rent in effect immediately prior to
such extended term.



2.	Section 4.B.ii is modified by adding "for Building
1" after "Commencement Date" in the only sentence of this
section.



3.		Section 4.D is replaced in its entirety by the
following:



Security Deposit



(i)	Amount: Tenant has deposited with Landlord a
letter of credit (`Letter of Credit") in a form reasonably acceptable to
Landlord in the amount of Eight Million Four Hundred Thousand Dollars
($8,400,000.00) to secure Tenant's obligation to complete Tennant Improvements
in the 
Building. Upon Landlord's receipt of evidence reasonably satisfactory to
Landlord of lien free completion of the Tenant Improvements and that Tenant has
fully paid for the cost of all Tenant Improvements for the Building, the Letter
of Credit shall be cancelled and returned to Tenant by Landlord.
Notwithstanding the foregoing, in the event Tenant elects to defer

construction on a portion of the non-core Tenant Improvements
in the Building (as provided further and restricted in Section 5.B), Landlord
shall not require Tenant to continue to post the Letter of Credit after payment
in full for all other Tenant Improvements associated with the Building.



(ii)	Use by Landlord:  Landlord shall be entitled
to draw against the full amount of the Letter of Credit at any time provided
only that Landlord certifies to the issuer of the Letter of Credit that Tenant
has failed to make a payment for Tenant Improvement costs as provided in 5.F,
that Tenant has failed to timely renew or extend the Letter of Credit as
required by this subsection (ii), or that Tenant has failed to amend the Letter
of Credit or obtain a new Letter of Credit as required by this subsection (ii)
and such failure has not been cured within ten (10) days following Landlord's
notice to Tenant.  Tenant shall keep the Letter of Credit in effect at all times
prior to payment in full for the Tenant Improvements for the Building.  At least
sixty (60) days prior to expiration of any Letter of Credit, the term thereof
shall be renewed or extended for a period until Tenant has paid in full for the
Tenant Improvements for the Building. Subject to the notice requirement and cure
period provided herein, Tenant's failure to so renew or extend the Letter of
Credit shall be a material default of this Lease by Tenant entitling Landlord to
draw down on the entire amount of the Letter of Credit.  Any amounts drawn on
the Letter of Credit shall be used to pay for the cost of the Tenant
Improvements.  In the event the Letter of Credit is drawn by Landlord, and the
proceeds used to pay for the completion of the Tenant Improvements in the
Building, after Landlord's completion of the Tenant Improvements in the
Building, Landlord shall refund to Tenant any excess proceeds from the Letter of
Credit.  In the event of termination of Landlord's interest in this Lease,
Landlord may deliver the Letter of Credit to Landlord's successor in interest in
the Premises and thereupon be relieved of further responsibility with respect to
the Letter of Credit.  Except as provided herein, no other security deposit
shall be required by Tenant.



(iii)	Letter of Credit Fee:  Landlord and Tenant
agree to share equally in the fee charged to provide the Letter of Credit.  In
no event, however, shall Landlord's share of the fee exceed the sum of Forty Two
Thousand Dollars ($42,000.00) per annum.



4.	The seventh through the ninth sentences of Section 5.A
beginning "Landlord shall contract for the installation" shall be
replaced in its entirety by "Landlord's affiliated construction company,
Sobrato Construction Corporation shall act as the general contractor for the
Building Shell and shall begin construction of the Building Shell immediately
following the Effective Date.  Upon completion of the Tenant Improvement Plans,
Landlord and Tenant shall select a general contractor ("General
Contractor") on the basis of a competitive bid of the cost to construct the
Tenant Improvements. Thereafter, Landlord shall cause the General Contractor to
complete construction of the Tenant Improvements.  Landlord and Sobrato
Construction shall use commercially reasonable efforts to ensure effective
coordination between the General Contractor selected to construct the Tenant
Improvements and Sobrato Construction Corporation."



5.	The first sentence of Section 5.J is replaced by
"Sobrato Construction Corporation and General Contractor shall each procure
(as a cost of the Building Shell or the Tenant Improvements as applicable) a
"Broad Form" liability insurance policies in the amount of Three
Million Dollars ($3,000,000.00)."



6.	The first three sentences of Section 5.K are replaced
by "After the Building Shell and Tenant Improvements are Substantially
Complete, Landlord shall cause Sobrato Construction Corporation and/or the
General Contractor to immediately correct any construction defect or other
"punch list" item which Tenant brings to Landlord's attention.  All
such work shall be performed so as to reasonably minimize the interruption to
Tenant and its activities on the Premises.  Sobrato Construction Corporation
shall provide a standard contractor's warranty with respect to the Building
Shell for one (1) year from the Commencement Date.  The General Contractor shall
provide
a standard contractor's warranty with respect to the Tenant
Improvements for one (1) year from the Commencement Date."



7.	Section 19 regarding Tenant's option to lease Building
3 is deleted and no longer applicable due to Tenant's concurrent execution of
the Building 3 Lease.



8.	All defined terms shall have the same meanings as in
the Lease, except as otherwise stated this Amendment.



9.	Except as hereby amended, the Lease and all of the
terms, covenants and conditions thereof shall remain unmodified and in full
force and effect.  In the event of any conflict or inconsistency between the
terms and provisions of this Amendment and the terms and provisions of the
Lease, the terms and provisions of this Amendment shall prevail.

IN WITNESS WHEREOF, the parties hereto have set their
hands to this Amendment as of the day and date first above written.



|LandlordSobrato Interests III,
a California limited partnership
By:/s/
Its: General Partner | TenantSiebel Systems, Inc.
a Delaware Corporation
By:/s/
Its: Director, Legal Affairs
|------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------

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10600 North De Anza Blvd.	408.446.0700
	Suite 200	Facsimile: 408.446.0583
	Cupertino CA 95014-2075	www.sobrato.com





DEVELOPMENT COMPANIES





SECOND
AMENDMENT TO LEASE



This second amendment to lease ("Amendment") is
made this 31ST day of July, 2000 ("Effective Date") by and
between Sobrato Interests III, a California limited partnership having an
address at 10600 N. De Anza Blvd, Suite 200, Cupertino, California 95014
("Landlord") and Siebel Systems, Inc., a Delaware corporation having
its principal place of business at 1855 South Grant Street, San Mateo, CA 94402
California ("Tenant").



WITNESSETH



WHEREAS Landlord and Tenant entered into a lease dated
March 11, 1999, and a First Amendment to Lease dated June 11, 1999 (the
"Lease") for the premises ("Premises") located at 2211
Bridgepointe Parkway, San Mateo, California; and



WHEREAS Landlord and Tenant wish to memorialize the
Lease Commencement date.



NOW, THEREFORE, in order to effect the intent of the
parties as se forth above and for good and valuable consideration exchanged
between the parties, the Lease is amended as of the Effective Date as
follows:



1.	The Lease Commencement date shall be May 22, 2000



2.	All defined terms shall have the same meanings as in
the Lease, except as otherwise stated in this Amendment.



3.	Except as hereby amended, the Lease and all of the
terms, covenants and conditions thereof shall remain unmodified and in full
force and effect.  In the event of any conflict or inconsistency between the
terms and provisions of this First Amendment and the terms and provisions of the
Lease, the terms and provisions of this First Amendment shall prevail.



IN WITNESS WHEREOF, the parties hereto have set their
hands to this Amendment as of the day and date first above written





|LandlordSobrato Interests III,
a California limited partnership
By:/s/
Its: General Partner | TenantSiebel Systems, Inc.
a Delaware Corporation
By:/s/
Its: Vice President, Facilities & Real Estate
|------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------

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