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                                                                   Exhibit 10.19

                           THIRD AMENDMENT TO LEASE
                           ------------------------

     This Third Amendment to Lease (the "Agreement") is made and entered into as
of January 11, 2000 by and between PENINSULA OFFICE PARK ASSOCIATES, L.P., a
California limited partnership ("Landlord") and BLUE MARTINI, INC., a California
corporation ("Tenant").

                                   Recitals
                                   --------

     A.   Landlord and Tenant entered into a Lease Agreement (the "Original
Lease") dated September 1, 1998, a First Amendment to Lease (the "First
Amendment") dated as of May 12, 1999, and a Second Amendment to Lease (the
"Second Amendment") dated as of August 5, 1999 (as so amended, the "Amended
Lease"). Under the terms of the Amended Lease, Tenant leases from Landlord Suite
175 (the "Initial Premises") containing approximately 6,819 rentable square feet
on the first floor, Suite 180 (the "First Expansion Premises") containing
approximately 5,108 rentable square feet on the first floor, and Suite 280 (the
"Second Expansion Premises") containing approximately 7,370 rentable square feet
on the second floor of the of the building known as Peninsula Office Park 6
located at 2600 Campus Drive, San Mateo, California (the "Building"). As of the
date of this Agreement the Premises contain approximately 19,297 rentable square
feet, consisting of the Initial Premises, the First Expansion Premises and
Second Expansion Premises (collectively, the "Existing Premises").

     B.   The Term of the Amended Lease is scheduled to expire August 31, 2004
(the "Expiration Date").

     C.   Landlord and Tenant desire to amend the Amended Lease to provide for
(i) Tenant to lease Suite 285 (the "Third Expansion Premises") containing
approximately 8,342 rentable square feet on the second floor of the Building,
(ii) an extension of the Term, and (iii) to make certain other changes in the
Amended Lease, all upon and subject to the terms and conditions set forth in
this Agreement. The approximate configuration and location of the Third
Expansion Premises is shown on Exhibit A attached hereto.

     NOW THEREFORE, in consideration of the foregoing recitals, and mutual
agreements contained herein, the parties hereto agree as follows:

1. Capitalized Terms. All capitalized terms not otherwise defined in this
   ------------------
   Agreement shall have the meaning given them in the Amended Lease.

2. Definition of Lease. The Amended Lease, as further amended by this Agreement,
   -------------------
   is herein called the "Lease."

3. Leasing of Third Expansion Premises. Subject to Landlord obtaining
   ------------------------------------
   possession of the Third Expansion Premises from the Existing Tenant (as
   defined below), Landlord leases

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   to Tenant and Tenant leases from Landlord the Third Expansion Premises
   commencing on the date Landlord delivers possession of the Third Expansion
   Premises to Tenant (herein called either the "Third Expansion Premises
   Commencement Date" or "TEPCD") after Landlord has (a) obtained possession of
   the Third Expansion Premises from the Existing Tenant, and (b) constructed
   the Demising Wall (as defined below). Commencing on the Third Expansion
   Premises Commencement Date and continuing through the Term, as extended
   herein, the Third Expansion Premises shall be included in the "Premises" for
   all purposes under the Lease (and the "Premises" shall consist of both the
   Existing Premises and the Third Expansion Premises, totaling approximately
   27,639 rentable square feet).

4. Existing Tenant. As of the date of this Agreement the Third Expansion
   ----------------
   Premises are occupied by a tenant (the "Existing Tenant") pursuant to a lease
   which expires April 30, 2001. Landlord agrees to use good faith efforts to
   enter into a partial lease termination agreement with the Existing Tenant and
   to deliver possession of the Third Expansion Premises to Tenant on or before
   January 31, 2000 (the "Scheduled Third Expansion Premises Commencement
   Date"), but Landlord shall not be liable for any claims, damages or
   liabilities if Landlord does not enter into a partial lease termination
   agreement for the Third Expansion Premises with the Existing Tenant, and
   Landlord is unable to deliver possession of the Third Expansion Premises to
   Tenant prior to the Scheduled Third Expansion Premises Commencement Date.
   Notwithstanding anything to the contrary contained in this Agreement, if
   Landlord has not delivered possession of the Third Expansion Premises to
   Tenant on or before February 29, 2000, then Tenant may terminate this
   Agreement by written notice to Landlord, such notice of termination to be
   given, if at all, on or before March 10, 2000. If Tenant terminates this
   Agreement pursuant to the provisions of the immediately preceding sentence,
   then the L/C (as defined below) delivered by Tenant to Landlord in connection
   with this Agreement shall immediately become invalid, and within ten (10)
   days after Landlord receives such notice from Tenant terminating this
   Agreement, Landlord shall return to Tenant (a) the original L/C, and (b) all
   Base Rent paid by Tenant to Landlord under this Agreement.

5. Term and Expiration Date. If this Agreement is not terminated pursuant to the
   -------------------------
   provisions of Paragraph 4 above, then the Term of the Lease is hereby
   extended by approximately five (5) calendar months to be sixty (60) full
   calendar months following the Third Expansion Premises Commencement Date. The
   Expiration Date is hereby changed to be January 31, 2005 (the "Revised
   Expiration Date").

6. Condition of Third Expansion Premises. Tenant hereby accepts the Third
   --------------------------------------
   Expansion Premises in their existing "AS IS" condition, agrees that the Third
   Expansion Premises is in good and tenantable condition, and acknowledges that
   Landlord has no obligation to improve or alter the Third Expansion Premises.
   Any Alterations Tenant makes to the Third Expansion Premises shall be made
   only in accordance with the provisions of Section 6 of the Original Lease.
   Tenant shall contract with Commercial Interior Contractors ("CIC") to
   construct any Alterations desired by Tenant in the Third Expansion Premises.
   The sums charged by CIC for any such Alterations shall be

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    competitive in the marketplace. Tenant acknowledges and agrees that CIC is
    an affiliate of Landlord. The cost of any Alterations shall be paid by
    Tenant to CIC.

7.  Demising Wall. Landlord shall contribute up to $44,000.00 (the "Allowance")
    --------------
    toward the cost of constructing and installing a demising wall (the
    "Demising Wall") between the Third Expansion Premises and Suite 200 in a
    good and workmanlike manner using Building standard materials. CIC shall
    construct such Demising Wall. Unless this Agreement is terminated by Tenant
    pursuant to the provisions of Paragraph 4 above, then Tenant shall be
    responsible for all costs in excess of the Allowance ("Additional Costs") to
    construct and install the Demising Wall. Tenant shall pay any Additional
    Costs to Landlord within ten (10) Business Days following Tenant's receipt
    of (a) an invoice for any such Additional Costs, and (b) evidence from
    Landlord that Landlord has paid to CIC the total costs of constructing and
    installing the Demising Wall.

8.  Base Rent for Third Expansion Premises. In addition to the Base Rent payable
    --------------------------------------
    by Tenant for the Existing Premises, Tenant shall pay the following Base
    Rent for the Third Expansion Premises:

        Months                  Base Rent
        ------                  ---------

        TEPCD - 01/14/01:       $3.45 per rentable square foot per month
        01/15/01 - 01/14/02:    $3.80 per rentable square foot per month
        01/15/02 - 01/14/03:    $3.90 per rentable square foot per month
        01/15/03 - 01/14/04:    $4.00 per rentable square foot per month
        01/15/04 - 01/31/05:    $4.10 per rentable square foot per month

9.  Base Rent for Existing Premises. Tenant shall pay Base Rent for the Existing
    -------------------------------
    Premises through August 31, 2004 in accordance with the provisions of the
    Amended Lease. Commencing September 1, 2004 and continuing until the Revised
    Expiration Date Tenant shall pay $4.10 per month per rentable square foot in
    the Existing Premises as Base Rent for the Existing Premises.

10. Base Year and Tenant's Share. The Base Year for the Third Expansion Premises
    ----------------------------
    shall be calendar year 2000. From and after the Third Expansion Premises
    Commencement Date Tenant's Share shall be 46.62%.

11. Letter of Credit.
    -----------------

       (a). Upon execution of this Agreement, Tenant shall deliver to Landlord
    an unconditional, irrevocable, transferable and negotiable standby letter of
    credit (the "L/C") in an amount equal to $96,350.10 ("Face Amount"), issued
    by a bank or trust company ("Issuer") and in form and content acceptable to
    Landlord, in its sole and absolute discretion, as additional security for
    the performance of Tenant's obligations under this Lease. An L/C in the form
    attached hereto as Exhibit B is hereby approved by Landlord. The L/C shall
                       ---------
    name Landlord as beneficiary thereunder and provide that draws, including
    partial draws, at Landlord's election, will be honored upon the delivery

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    to the Issuer of a certificate signed by Landlord, or its authorized agent,
    that Tenant has failed to perform its obligations under the Lease. The L/C
    shall also provide that it will be automatically extended upon each renewal
    date unless the Issuer thereof delivers to Landlord, no later than forty-
    five (45) days prior to the stated expiration date of the L/C, written
    notice of Issuer's intent not to extend or renew the L/C. During any period
    that Tenant is required to maintain the L/C, Tenant shall, at least thirty
    (30) days prior to any expiration or termination of the L/C, provide
    Landlord either with written confirmation that the existing L/C will be
    automatically extended and renewed or with a new L/C that satisfies all of
    the requirements for the L/C in this Paragraph 12. In addition, upon a
    proposed sale or other transfer of any interest in the Building, the Land,
    this Lease or Landlord (including consolidations, mergers, or other entity
    changes), Tenant, at its sole cost and expense and upon ten (10) Business
    Days' notice, shall, concurrent with Landlord's delivery to Tenant of the
    then outstanding L/C, deliver to any such transferees, successors, or
    assigns a replacement L/C on identical terms (except for the stated
    beneficiary) from the same Issuer or another bank or trust company
    acceptable to Landlord, in Landlord's sole discretion, naming the new
    landlord as the beneficiary thereof. Tenant's failure to perform or observe
    any of the covenants set forth in this Paragraph 12 for any reason shall
    entitle Landlord to draw on the full amount of the L/C and shall constitute
    an Event of Default under this Lease without the requirement of any notice
    from Landlord. Any amount(s) drawn under the L/C shall be held or used by
    Landlord in accordance with the terms of Section 4 of the Lease.

       (b). If as of the first (1st), second (2nd), third (3rd) and fourth (4th)
    anniversary dates following the Third Expansion Premises Commencement Date,
    (i) no prior or current Event of Default has occurred, and no event or
    condition exists or has occurred which with the passage of time or delivery
    of notice by Landlord, or both, would constitute an Event of Default, and
    (ii) Tenant has delivered to Landlord, on or before such anniversary dates,
    audited financial statements prepared in accordance with generally accepted
    accounting principles consistently applied and certified by Tenant's chief
    financial officer as being complete and accurate which confirm that Tenant
    has achieved and sustained positive net earnings for each of the four
    consecutive calendar quarters immediately preceding each applicable
    anniversary date, the Face Amount of the L/C may be immediately reduced to
    (A) $77,080.10 on the first (1st) anniversary date of the Third Expansion
    Premises Commencement Date, (B) $57,810.06 on the second (2nd) anniversary
    date of the Third Expansion Premises Commencement Date, (C) $38,540.10 on
    the third (3rd) anniversary date of the Third Expansion Premises
    Commencement Date, and (D) $19,270.02 on the fourth (4th) anniversary date
    of the Third Expansion Premises Commencement Date, as applicable (the "L/C
    Burnoff").

12. Broker. Tenant warrants and represents to Landlord that in the negotiating
    -------
    or making of this Agreement neither Tenant nor anyone acting on Tenant's
    behalf has dealt with any broker or finder who might be entitled to a fee or
    commission for this Agreement. Tenant shall indemnify and hold Landlord
    harmless from any claim or claims, including costs, expenses and attorney's
    fees incurred by Landlord asserted by any broker or finder for a fee or
    commission based upon any dealings with or statements made by

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    Tenant or Tenant's Representatives. Landlord agrees to indemnify and hold
    Tenant harmless from and against any claim by third parties claiming by,
    through, or under Landlord for commissions due or alleged to be due in
    connection with this Agreement.

13. Ratification of Amended Lease. The Amended Lease, as modified by this
    ------------------------------
    Agreement, remains in full force and effect, and Landlord and Tenant ratify
    the same. This Agreement shall be binding upon and inure to the benefit of
    the parties and their respective successors and assigns.

      If Tenant is a corporation or a partnership, each of the persons executing
this Agreement on behalf of Tenant warrants and represents that Tenant is a duly
authorized and existing entity that Tenant has full right and authority to enter
into this Agreement and that the persons signing on behalf of Tenant are
authorized to do so and have the power to bind Tenant to this Agreement. Tenant
shall provide Landlord, upon request, with evidence reasonably satisfactory to
Landlord confirming the foregoing representations.

      Except as herein amended, the Amended Lease remains unchanged and is in
full force and effect in accordance with the terms and provisions contained
therein.

      This Third Amendment is hereby executed and delivered in multiple
counterparts, each of which shall have the force and effect of an original.

LANDLORD:                                    TENANT:

PENINSULA OFFICE PARK ASSOCIATES, L.P.,      BLUE MARTINI, INC.,
a California limited partnership             a California corporation

By:   CORNERSTONE HOLDINGS, INC.,            By: /s/ Monte Zweben
                                                 ---------------------------
      a Delaware limited liability company,       Name: Monte Zweben
                                                        --------------------
      general partner                             Title: President and CEO
                                                         -------------------
      By:  /s/ Robert Paratte                By:  __________________________
           -------------------------------
      Name: Robert Paratte                        Name:  ___________________
            ------------------------------
      Title: _____________________________        Title:  __________________


(For corporate entities, signature by TWO corporate officers is required: one by
(x) the chairman of the board, the president, or any vice president; and the
other by (y) the secretary, any assistant secretary, the chief financial
officer, or any assistant treasurer.)

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                                   EXHIBIT A
                                   ---------

                       ATTACHED TO AND FORMING A PART OF
                           THIRD AMENDMENT TO LEASE
                         DATED AS OF JANUARY 11, 2000
                                    BETWEEN
             PENINSULA OFFICE PARK ASSOCIATES, L.P., AS LANDLORD,
                                      AND
                  BLUE MARTINI, INC., AS TENANT ("AGREEMENT")


                         THE THIRD EXPANSION PREMISES
                         ----------------------------



                         [Floor plan showing location
                 and configuration of Third Expansion Premises
                               to be inserted.]



                                                              INITIALS:

                                                              Landlord  RP
                                                              Tenant    MZ
<PAGE>

                                   EXHIBIT B
                                   ---------

                       ATTACHED TO AND FORMING A PART OF
                            THIRD AMENDMENT TO LEASE
                          DATED AS OF JANUARY 11, 2000
                                    BETWEEN
              PENINSULA OFFICE PARK ASSOCIATES, L.P., AS LANDLORD,
                                      AND
                  BLUE MARTINI, INC., AS TENANT ("AGREEMENT")


                         APPROVED LETTER OF CREDIT FORM
                         ------------------------------

[Letterhead of Issuing Bank]
[must be a Bank whose location, credit and practices Landlord has approved]


RE:  IRREVOCABLE COMMERCIAL LETTER OF CREDIT NO. _________

TO:  [Name of project owner] ("Landlord"), _____________________________________
__________________ [Landlord's address]

Gentlemen:

We hereby issue our Irrevocable Commercial Letter of Credit in your favor, for
the account of _____________________________ [name of tenant and type of entity
(e.g. "ABC Corporation, a California corporation")] ("Tenant"), in the amount of
______________________________ Dollars ($__________). This amount is available
to you on presentation of your sight draft drawn upon us referring to the above
letter of credit number, date and amount being drawn hereunder, accompanied by
the signed statement of you or your authorized agent, Cornerstone Properties
Limited Partnership dba Wilson Cornerstone Properties Limited Partnership, that
the amount drawn hereunder is being drawn pursuant to the terms of the
_______________ [title of lease document (e.g. Office Lease, Lease Agreement,
etc.)] dated as of __________, between Tenant, as tenant, and Landlord, as
landlord, for certain premises located at _______________
__________________________ (the "Lease").

Any draft presented for payment must be presented on or before ________________
[term should be at least one year], the date this Letter of Credit expires.
Partial drawings are permitted.

If you sell or otherwise transfer any interest in the "Building" (as defined in
the Lease) [be sure to use the defined terms used in the Lease (e.g. if the
building is called the "Property" in the Lease, then use that term here)], in
the land upon which the same is located, in the Lease, or in

                               Exhibit B, Page 1
<PAGE>

Landlord (including consolidations, mergers or other entity changes), you shall
have the right to transfer this Letter of Credit to your transferee(s),
successors or assigns.

We hereby certify that this is an unconditional and irrevocable Letter of Credit
and agree that a draft drawn under and in compliance with the terms hereof will
be honored upon presentation at our office at _________________________________
[it must be a location easily accessible to us (e.g. no country banks located in
some tiny town in the Southeastern corner of Texas].

This Letter of Credit shall automatically be extended and renewed for successive
one year periods at the end of the stated expiration date and each anniversary
thereof unless we notify you in writing, no later than forty-five (45) days
prior to the then applicable expiration date, that we will not extend and renew
the Letter of Credit for another one year term.



Except to the extent inconsistent with the express provisions hereof, this
Letter of Credit is subject to and governed by Uniform Customs and Practice for
Documentary Credits (1993 Revision) International Chamber of Commerce
publication number 500.

                                               [Name of Bank]



                                               _________________________________
                                               Authorized Signature

INITIALS:
Landlord  ______
Tenant    ______