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                                                                    EXHIBIT 10.3

                           QUALIFIED BORROWER GUARANTY

            UNCONDITIONAL GUARANTY OF PAYMENT (this "Guaranty"), is made as of
June 1, 2004 by AMB PROPERTY, L.P., a Delaware limited partnership (the
"Guarantor") for the benefit of JPMORGAN CHASE BANK, as Administrative Agent and
J.P. MORGAN EUROPE LIMITED, as Administrative Agent (collectively, the
"Administrative Agent") for the banks (the "Banks") that are from time to time
parties to that certain Second Amended and Restated Revolving Credit Agreement
(the "Credit Agreement"), dated as of the date hereof, among the Guarantor, the
banks listed on the signature pages thereof, the Administrative Agent, Bank of
America, N.A., as Syndication Agent, J.P. Morgan Securities Inc. and Banc of
America Securities LLC, as Joint Lead Arrangers and Joint Bookrunners,
Commerzbank Aktiengesellschaft New York and Grand Cayman Branches, PNC Bank,
National Association, and Wachovia Bank, N.A., as Documentation Agents, Keybank
National Association, The Bank of Nova Scotia, acting through its San Francisco
Agency, and Wells Fargo Bank, N.A., as Managing Agents, and ING Real Estate
Finance (USA) LLC, SouthTrust Bank and Union Bank of California, N.A., as
Co-Agents.

            Capitalized terms not otherwise defined in this Guaranty shall have
the meanings ascribed to them in the Credit Agreement.

                              W I T N E S S E T H:

            WHEREAS, pursuant to the terms of the Credit Agreement, a Qualified
Borrower may request that the Banks make one or more loans (each, a "Loan") to
the Qualified Borrower, to be guaranteed by Guarantor by this Guaranty and to be
evidenced by Qualified Borrower Notes (collectively, the "Note"), payable by the
Qualified Borrower to the order of the Banks.

            WHEREAS, this Guaranty is the "Qualified Borrower Guaranty" referred
to in the Credit Agreement;

            WHEREAS, in order to induce the Administrative Agent and the Banks
to make one or more Loans to one or more Qualified Borrowers, and to satisfy one
of the conditions contained in the Credit Agreement with respect thereto, the
Guarantor has agreed to enter into this Guaranty.

            NOW THEREFORE, in consideration of the premises and the direct and
indirect benefits to be derived from the making of the Loans by the Banks to
Qualified Borrowers, and for other good and valuable consideration, the receipt
and sufficiency of which is hereby acknowledged, Guarantor hereby agrees as
follows:

            i.    Guarantor, on behalf of itself and its successors and assigns,
hereby irrevocably, absolutely, and unconditionally guarantees the full and
punctual payment when due, whether at stated maturity or otherwise, of all
obligations of each and every Qualified Borrower

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now or hereafter existing under the Note (whether executed and delivered
simultaneously herewith or subsequently), or under any of the other Loan
Documents (such obligations, whenever arising, being the "Guaranteed
Obligations"), and any and all reasonable costs and expenses (including, without
limitation, reasonable attorneys' fees and disbursements) incurred by the
Administrative Agent in enforcing its rights under this Guaranty.

            ii.   It is agreed that the obligations of Guarantor hereunder are
primary and this Guaranty shall be enforceable against Guarantor and its
successors and assigns without the necessity for any suit or proceeding of any
kind or nature whatsoever brought by the Administrative Agent against the
relevant Qualified Borrower or its respective successors or assigns or any other
party or against any security for the payment and performance of the Guaranteed
Obligations and without the necessity of any notice of non-payment or
non-observance or of any notice of acceptance of this Guaranty or of any notice
or demand to which Guarantor might otherwise be entitled (including, without
limitation, diligence, presentment, notice of maturity, extension of time,
change in nature or form of the Guaranteed Obligations, acceptance of further
security, release of further security, imposition or agreement arrived at as to
the amount of or the terms of the Guaranteed Obligations, notice of adverse
change in such Qualified Borrower's financial condition and any other fact which
might materially increase the risk to Guarantor), all of which Guarantor hereby
expressly waives; and Guarantor hereby expressly agrees that the validity of
this Guaranty and the obligations of the Guarantor hereunder shall in no way be
terminated, affected, diminished, modified or impaired by reason of the
assertion of or the failure to assert by the Administrative Agent against such
Qualified Borrower or its respective successors or assigns, any of the rights or
remedies reserved to the Administrative Agent pursuant to the provisions of the
Loan Documents. Guarantor hereby agrees that any notice or directive given at
any time to the Administrative Agent which is inconsistent with the waiver in
the immediately preceding sentence shall be void and may be ignored by the
Administrative Agent, and, in addition, may not be pleaded or introduced as
evidence in any litigation relating to this Guaranty for the reason that such
pleading or introduction would be at variance with the written terms of this
Guaranty, unless the Administrative Agent has specifically agreed otherwise in a
writing, signed by a duly authorized officer. Guarantor specifically
acknowledges and agrees that the foregoing waivers are of the essence of this
transaction and that, but for this Guaranty and such waivers, the Banks would
not make Loans and the Fronting Bank would not issue Letters of Credit on behalf
of any Qualified Borrower.

            iii.  Guarantor hereby waives, and covenants and agrees that it will
not at any time insist upon, plead or in any manner whatsoever claim or take the
benefit or advantage of, any and all appraisal, valuation, stay, extension,
marshaling-of-assets or redemption laws, or right of homestead or exemption,
whether now or at any time hereafter in force, which may delay, prevent or
otherwise affect the performance by Guarantor of its obligations under, or the
enforcement by the Administrative Agent of, this Guaranty. Guarantor further
covenants and agrees not to set up or claim any defense, counterclaim, offset,
set-off or other objection of any kind to any action, suit or proceeding in law,
equity or otherwise, or to any demand or claim that may be instituted or made by
the Administrative Agent other than the defense of the actual timely payment and
performance by the relevant Qualified Borrower of the Guaranteed Obligations

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hereunder; provided, however, that the foregoing shall not be deemed a waiver of
Guarantor's right to assert any compulsory counterclaim, if such counterclaim is
compelled under local law or rule of procedure, nor shall the foregoing be
deemed a waiver of Guarantor's right to assert any claim which would constitute
a defense, setoff, counterclaim or crossclaim of any nature whatsoever against
Administrative Agent or any Bank in any separate action or proceeding. Guarantor
represents, warrants and agrees that, as of the date hereof, its obligations
under this Guaranty are not subject to any counterclaims, offsets or defenses of
any kind against the Administrative Agent, the Banks or the Fronting Bank.

            iv.   The provisions of this Guaranty are for the benefit of the
Administrative Agent on behalf of the Banks and their successors and permitted
assigns, and nothing herein contained shall impair as between any Qualified
Borrower and the Administrative Agent the obligations of such Qualified Borrower
under the Loan Documents.

            v.    This Guaranty shall be a continuing, unconditional and
absolute guaranty and the liability of Guarantor hereunder shall in no way be
terminated, affected, modified, impaired or diminished by reason of the
happening, from time to time, of any of the following, all without notice or the
further consent of Guarantor:

                        (1)   any assignment, amendment, modification or waiver
                              of or change in any of the terms, covenants,
                              conditions or provisions of any of the Guaranteed
                              Obligations or the Loan Documents or the
                              invalidity or unenforceability of any of the
                              foregoing; or

                        (2)   any extension of time that may be granted by the
                              Administrative Agent to any Qualified Borrower,
                              any guarantor, or their respective successors or
                              assigns, heirs, executors, administrators or
                              personal representatives; or

                        (3)   any action which the Administrative Agent may take
                              or fail to take under or in respect of any of the
                              Loan Documents or by reason of any waiver of, or
                              failure to enforce any of the rights, remedies,
                              powers or privileges available to the
                              Administrative Agent under this Guaranty or
                              available to the Administrative Agent at law,
                              equity or otherwise, or any action on the part of
                              the Administrative Agent granting indulgence or
                              extension in any form whatsoever; or

                        (4)   any sale, exchange, release, or other disposition
                              of any property pledged, mortgaged or conveyed, or
                              any property in which the Administrative Agent
                              and/or the Banks have been granted a lien or
                              security interest to secure any indebtedness of
                              any Qualified Borrower to the Administrative Agent
                              and/or the Banks; or

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                        (5)   any release of any person or entity who may be
                              liable in any manner for the payment and
                              collection of any amounts owed by any Qualified
                              Borrower to the Administrative Agent and/or the
                              Banks; or

                        (6)   the application of any sums by whomsoever paid or
                              however realized to any amounts owing by any
                              Qualified Borrower to the Administrative Agent
                              and/or the Banks under the Loan Documents in such
                              manner as the Administrative Agent shall determine
                              in its sole discretion; or

                        (7)   any Qualified Borrower's or the Guarantor's
                              voluntary or involuntary liquidation, dissolution,
                              sale of all or substantially all of their
                              respective assets and liabilities, appointment of
                              a trustee, receiver, liquidator, sequestrator or
                              conservator for all or any part of any Qualified
                              Borrower's or Guarantor's assets, insolvency,
                              bankruptcy, assignment for the benefit of
                              creditors, reorganization, arrangement,
                              composition or readjustment, or the commencement
                              of other similar proceedings affecting any
                              Qualified Borrower or Guarantor or any of the
                              assets of any of them, including, without
                              limitation, (i) the release or discharge of any
                              Qualified Borrower or Guarantor from the payment
                              and performance of their respective obligations
                              under any of the Loan Documents by operation of
                              law, or (ii) the impairment, limitation or
                              modification of the liability of any Qualified
                              Borrower or Guarantor in bankruptcy, or of any
                              remedy for the enforcement of the Guaranteed
                              Obligations under any of the Loan Documents, or
                              Guarantor's liability under this Guaranty,
                              resulting from the operation of any present or
                              future provisions of the Bankruptcy Code or other
                              present or future federal, state or applicable
                              statute or law or from the decision in any court;
                              or

                        (8)   any improper disposition by any Qualified Borrower
                              of the proceeds of the Loans, it being
                              acknowledged by Guarantor that the Administrative
                              Agent shall be entitled to honor any request made
                              by any Qualified Borrower for a disbursement of
                              such proceeds and that the Administrative Agent
                              shall have no obligation to see the proper
                              disposition by such Qualified Borrower of such
                              proceeds.

                        (9)   Guarantor hereby agrees that if at any time all or
                              any part of any payment at any time received by
                              the Administrative Agent from any Qualified
                              Borrower under any of the Notes or other Loan
                              Documents or Guarantor under or with respect to
                              this Guaranty is or must be rescinded or returned
                              by the Administrative Agent for

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                              any reason whatsoever (including, without
                              limitation, the insolvency, bankruptcy or
                              reorganization of any Qualified Borrower or
                              Guarantor), then Guarantor's obligations hereunder
                              shall, to the extent of the payment rescinded or
                              returned, be deemed to have continued in existence
                              notwithstanding such previous receipt by the
                              Administrative Agent, and Guarantor's obligations
                              hereunder shall continue to be effective or
                              reinstated, as the case may be, as to such
                              payment, as though such previous payment to the
                              Administrative Agent had never been made.

                        (10)  Until this Guaranty is terminated pursuant to the
                              terms hereof, the Guarantor (i) shall have no
                              right of subrogation against any Qualified
                              Borrower or any entity comprising same by reason
                              of any payments or acts of performance by
                              Guarantor in compliance with the obligations of
                              Guarantor hereunder; (ii) hereby waives any right
                              to enforce any remedy which Guarantor now or
                              hereafter shall have against any Qualified
                              Borrower or any entity comprising same by reason
                              of any one or more payment or acts of performance
                              in compliance with the obligations of Guarantor
                              hereunder; and (iii) from and after an Event of
                              Default (as defined in the Credit Agreement)
                              subordinates any liability or indebtedness of any
                              Qualified Borrower or any entity comprising same
                              now or hereafter held by Guarantor to the
                              obligations of each Qualified Borrower under the
                              Loan Documents.

            vi.   Guarantor hereby represents, warrants and covenants on its own
behalf to the Administrative Agent with the knowledge that the Administrative
Agent is relying upon the same, as follows:

                        (1)   Guarantor will be familiar with the financial
                              condition of each Qualified Borrower;

                        (2)   Guarantor has determined that it is in its best
                              interest to enter into this Guaranty;

                        (3)   this Guaranty is necessary and convenient to the
                              conduct, promotion and attainment of Guarantor's
                              business, and is in furtherance of Guarantor's
                              business purposes;

                        (4)   the benefits to be derived by Guarantor from each
                              Qualified Borrower's access to funds made possible
                              by the Loan Documents are at least equal to the
                              obligations of Guarantor undertaken pursuant to
                              this Guaranty;

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                        (5)   the Guarantor is solvent and has full partnership
                              power and legal right to enter into this Guaranty
                              and to perform its obligations under the terms
                              hereof and (i) Guarantor is organized and validly
                              existing under the laws of its state of formation,
                              (ii) Guarantor has complied with all provisions of
                              applicable law in connection with all aspects of
                              this Guaranty, and (iii) the person executing this
                              Guaranty on behalf of Guarantor has all the
                              requisite power and authority to execute and
                              deliver this Guaranty; and

                        (6)   this Guaranty has been duly executed by Guarantor
                              and constitutes the legal, valid and binding
                              obligation of Guarantor, enforceable against it in
                              accordance with its terms except as enforceability
                              may be limited by applicable insolvency,
                              bankruptcy or other laws affecting creditors'
                              rights generally or general principles of equity
                              whether such enforceability is considered in a
                              proceeding in equity or at law.

      The foregoing representations and warranties shall be deemed to be made as
of the date hereof and as the date of the making any Loan or the issuance of any
Letter of Credit to or for the account on any Qualified Borrower.

            vii. Each of Guarantor and the Administrative Agent acknowledges and
agrees that this Guaranty is a guaranty of payment and not of collection and
enforcement in respect of any obligations which may accrue to the Administrative
Agent and/or the Banks from each Qualified Borrower under the provisions of any
Loan Document.

            viii. Subject to the terms and conditions of the Credit Agreement,
and in conjunction therewith, the Administrative Agent may assign any or all of
its rights under this Guaranty.

            ix. Guarantor agrees, upon the written request of the Administrative
Agent, to execute and deliver to the Administrative Agent, from time to time,
any modification or amendment hereto or any additional instruments or documents
reasonably considered necessary by the Administrative Agent or its counsel to
cause this Guaranty to be, become or remain valid and effective in accordance
with its terms, provided, that, any such modification, amendment, additional
instrument or document shall not increase Guarantor's obligations or diminish
its rights hereunder and shall be reasonably satisfactory as to form to
Guarantor and to Guarantor's counsel.

            x. The representations and warranties of the Guarantor set forth in
this Guaranty shall survive until this Guaranty shall terminate in accordance
with the terms hereof.

            xi. This Guaranty together with the Credit Agreement, each Note now
or hereafter executed and delivered by any Qualified Borrower, and the other
Loan Documents

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contain the entire agreement among the parties with respect to the subject
matter hereof and supersedes all prior agreements relating to such subject
matter and may not be modified, amended, supplemented or discharged except by a
written agreement signed by Guarantor and the Administrative Agent.

            xii. If all or any portion of any provision contained in this
Guaranty shall be determined to be invalid, illegal or unenforceable in any
respect for any reason, such provision or portion thereof shall be deemed
stricken and severed from this Guaranty and the remaining provisions and
portions thereof shall continue in full force and effect.

            xiii. This Guaranty may be executed in counterparts which together
shall constitute the same instrument.

            xiv. All notices, requests and other communications to any party
hereunder shall be in writing (including bank wire, telex, facsimile
transmission followed by telephonic confirmation or similar writing) and shall
be addressed to such party at the address set forth below or to such other
address as may be identified by any party in a written notice to the others:

If to a
Qualified Borrower:                 At the address identified therefor by
                                    Borrower at the time such Qualified Borrower
                                    delivers its Note or, if no such address is
                                    so identified, at the address of Borrower
                                    set forth in the Credit Agreement for
                                    notices.

If to
Guarantor:                          At the address set forth in the Credit
                                    Agreement for notices.

With Copies of
Notices to the
Qualified Borrower
or Guarantor to:                    Piper Rudnick LLP
                                    203 North LaSalle Street, Suite 1800
                                    Chicago, Illinois 60601
                                    Attention: James M. Phipps, Esq.

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If to the Administrative Agent:     JPMorgan Chase Bank
                                    707 Travis Street, 6th Floor North
                                    Houston, Texas  77002
                                    Attention: Susan M. Tate

and to:                             JPMorgan Chase Bank
                                    1111 Fannin Street, 10th Floor
                                    Houston, Texas  77002
                                    Attention: Loan and Agency Services

With Copies to:                     Skadden, Arps, Slate, Meagher & Flom LLP
                                    4 Times Square
                                    New York, New York 10036
                                    Attention:  Martha Feltenstein, Esq.

            Each such notice, request or other communication shall be effective
(i) if given by telex or facsimile transmission, when such telex or facsimile is
transmitted to the telex number or facsimile number specified in this Section
and the appropriate answerback or facsimile confirmation is received, (ii) if
given by certified registered mail, return receipt requested, with first class
postage prepaid, addressed as aforesaid, upon receipt or refusal to accept
delivery, (iii) if given by a nationally recognized overnight carrier, 24 hours
after such communication is deposited with such carrier with postage prepaid for
next day delivery, or (iv) if given by any other means, when delivered at the
address specified in this Section.

            xv. This Guaranty shall be binding upon Guarantor and its successors
and assigns and shall inure to the benefit of the Administrative Agent and its
successors and assigns.

            xvi. The failure of the Administrative Agent to enforce any right or
remedy hereunder, or promptly to enforce any such right or remedy, shall not
constitute a waiver thereof, nor give rise to any estoppel against the
Administrative Agent, nor excuse Guarantor from its obligations hereunder. Any
waiver of any such right or remedy to be enforceable against the Administrative
Agent must be expressly set forth in a writing signed by the Administrative
Agent.

            xvii.           (1)   THIS GUARANTY AND THE RIGHTS AND OBLIGATIONS
                                  OF THE PARTIES HEREUNDER SHALL BE CONSTRUED
                                  IN ACCORDANCE WITH AND BE GOVERNED BY THE
                                  LAWS OF THE STATE OF NEW YORK.

                  (2)   Any legal action or proceeding with respect to this
                        Guaranty and any action for enforcement of any judgment
                        in respect thereof may be brought in the courts of the
                        State of New York or of the United States of America for
                        the Southern District of New York, and, by

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                        execution and delivery of this Guaranty, Guarantor
                        hereby accepts for itself and in respect of its
                        property, generally and unconditionally, the
                        non-exclusive jurisdiction of the aforesaid courts and
                        appellate courts from any thereof. Guarantor irrevocably
                        consents to the service of process out of any of the
                        aforementioned courts in any such action or proceeding
                        by the mailing of copies thereof by registered or
                        certified mail, postage prepaid, to Guarantor at the
                        address for notices set forth herein. Guarantor hereby
                        irrevocably waives any objection which it may now or
                        hereafter have to the laying of venue of any of the
                        aforesaid actions or proceedings arising out of or in
                        connection with this Guaranty brought in the courts
                        referred to above and hereby further irrevocably waives
                        and agrees not to plead or claim in any such court that
                        any such action or proceeding brought in any such court
                        has been brought in an inconvenient forum. Nothing
                        herein shall affect the right of the Administrative
                        Agent to serve process in any other manner permitted by
                        law or to commence legal proceedings or otherwise
                        proceed against Guarantor in any other jurisdiction.

                  (3)   EACH OF THE GUARANTOR AND THE ADMINISTRATIVE AGENT
                        HEREBY WAIVES ITS RIGHTS TO A JURY TRIAL OF ANY AND ALL
                        CLAIMS OR CAUSES OF ACTION BASED UPON OR ARISING OUT OF
                        THIS GUARANTY. IT IS HEREBY ACKNOWLEDGED BY GUARANTOR
                        THAT THE WAIVER OF A JURY TRIAL IS A MATERIAL INDUCEMENT
                        FOR THE ADMINISTRATIVE AGENT TO ACCEPT THIS GUARANTY AND
                        THAT THE LOANS MADE BY THE BANKS ARE MADE IN RELIANCE
                        UPON SUCH WAIVER. GUARANTOR FURTHER WARRANTS AND
                        REPRESENTS THAT SUCH WAIVER HAS BEEN KNOWINGLY AND
                        VOLUNTARILY MADE, FOLLOWING CONSULTATION WITH LEGAL
                        COUNSEL. IN THE EVENT OF LITIGATION, THIS GUARANTY MAY
                        BE FILED BY THE ADMINISTRATIVE AGENT IN COURT AS A
                        WRITTEN CONSENT TO A NON-JURY TRIAL.

                  (4)   Guarantor hereby further covenants and agrees with the
                        Administrative Agent that Guarantor may be joined in any
                        action against the Qualified Borrower in connection with
                        the Loan Documents and that recovery may be had against
                        Guarantor in such action or in any independent action
                        against Guarantor (with respect to the Guaranteed
                        Obligations), without the Administrative Agent first
                        pursuing or exhausting any remedy or claim against the
                        Qualified Borrower or its successors or assigns.
                        Guarantor also agrees that,

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                        in an action brought with respect to the Guaranteed
                        Obligations in any jurisdiction, it shall be
                        conclusively bound by the judgment in any such action by
                        the Administrative Agent (wherever brought) against any
                        Qualified Borrower or its successors or assigns, as if
                        Guarantor were a party to such action, even though
                        Guarantor was not joined as a party in such action.

                  (5)   Guarantor hereby agrees to pay all reasonable expenses
                        (including, without limitation, attorneys' fees and
                        disbursements) which may be incurred by the
                        Administrative Agent in connection with the enforcement
                        of its rights under this Guaranty, whether or not suit
                        is initiated.

            xvii. Subject to the terms of Section 5(i) hereof, this Guaranty
shall terminate and be of no further force or effect upon the full performance
and payment of the Guaranteed Obligations hereunder. Upon termination of this
Guaranty in accordance with the terms of this Guaranty, the Administrative Agent
promptly shall deliver to Guarantor such documents as Guarantor or Guarantor's
counsel reasonably may request in order to evidence such termination.

            xviii. All of the Administrative Agent's rights and remedies under
each of the Loan Documents or under this Guaranty are intended to be distinct,
separate and cumulative and no such right or remedy therein or herein mentioned
is intended to be in exclusion of or a waiver of any other right or remedy
available to the Administrative Agent.

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                        IN WITNESS WHEREOF, the undersigned has cause this
Guaranty to be duly executed and delivered as of the date first set forth above.

                                  GUARANTOR:

                                  AMB PROPERTY, L.P.,
                                  a Delaware limited partnership

                                  By:   AMB Property Corporation, a Maryland
                                        corporation and its sole general partner


                                        By: /s/ Gayle P. Starr
                                           ______________________________
                                        Name:  Gayle P. Starr
                                        Title: Senior Vice President

ACCEPTED:

JPMORGAN CHASE BANK,
as Administrative Agent

By:   /s/ Susan Tate
      _____________________
      Name:  Susan Tate
      Title: Vice President

J.P. MORGAN EUROPE LIMITED, as Administrative Agent

By:   /s/ S. Gillies             By:   /s/ N. Mall
      _____________________           _____________________
      Name:  S. Gillies               Name:  N. Mall
      Title: Associate                Title: Associate