**Exhibit10.9**QUALIFIED BORROWER GUARANTY          UNCONDITIONALGUARANTY OF PAYMENT (this “Guaranty”), is made as ofJune 1, 2006 by AMBPROPERTY, L.P., a Delaware limited partnership (the “Guarantor”) for the benefit of JPMORGAN CHASEBANK, N.A., 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 timeparties to that certain Third Amended and Restated Revolving Credit Agreement (the “CreditAgreement”), dated as of the date hereof, among the Guarantor, the banks listed on the signaturepages thereof, the Administrative Agent, Bank of America, N.A., as Syndication Agent, J.P. MorganSecurities Inc. and Banc of America Securities LLC, as Joint Lead Arrangers and Joint Bookrunners,Eurohypo AG, New York Branch, Wachovia Bank, N.A., and PNC Bank, National Association, asDocumentation Agents, and The Bank of Nova Scotia, acting through its San Francisco Agency, WellsFargo Bank, N.A., ING Real Estate Finance (USA) LLC, and LaSalle Bank National Association, asManaging Agents.          Capitalized terms not otherwise defined in this Guaranty shall have the meanings ascribed tothem in the Credit Agreement.WITNESSETH:          WHEREAS, pursuant to the terms of the Credit Agreement, a Qualified Borrower may request thatthe Banks make one or more loans (each, a “Loan”) to the Qualified Borrower, to be guaranteed byGuarantor 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 CreditAgreement;          WHEREAS, in order to induce the Administrative Agent and the Banks to make one or more Loansto one or more Qualified Borrowers, and to satisfy one of the conditions contained in the CreditAgreement 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 bederived from the making of the Loans by the Banks to Qualified Borrowers, and for other good andvaluable consideration, the receipt and sufficiency of which is hereby acknowledged, Guarantorhereby agrees as follows:          1. Guarantor, on behalf of itself and its successors and assigns, hereby irrevocably,absolutely, and unconditionally guarantees the full and punctual payment when due, whether atstated maturity or otherwise, of all obligations of each and every Qualified Borrower now orhereafter existing under the Note (whether executed and delivered simultaneously
 

 
herewith or subsequently), or under any of the other LoanDocuments (such obligations, whenever arising, being the “Guaranteed Obligations”), and any and allreasonable costs and expenses (including, without limitation, reasonable attorneys’ fees anddisbursements) incurred by the Administrative Agent in enforcing its rights under this Guaranty.          2. It is agreed that the obligations of Guarantor hereunder are primary and this Guarantyshall be enforceable against Guarantor and its successors and assigns without the necessity for anysuit or proceeding of any kind or nature whatsoever brought by the Administrative Agent against therelevant Qualified Borrower or its respective successors or assigns or any other party or againstany security for the payment and performance of the Guaranteed Obligations and without thenecessity of any notice of non-payment or non-observance or of any notice of acceptance of thisGuaranty 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 natureor 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 whichmight 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 theGuarantor hereunder shall in no way be terminated, affected, diminished, modified or impaired byreason of the assertion of or the failure to assert by the Administrative Agent against suchQualified Borrower or its respective successors or assigns, any of the rights or remedies reservedto the Administrative Agent pursuant to the provisions of the Loan Documents. Guarantor herebyagrees that any notice or directive given at any time to the Administrative Agent which isinconsistent with the waiver in the immediately preceding sentence shall be void and may be ignoredby the Administrative Agent, and, in addition, may not be pleaded or introduced as evidence in anylitigation relating to this Guaranty for the reason that such pleading or introduction would be atvariance with the written terms of this Guaranty, unless the Administrative Agent has specificallyagreed otherwise in a writing, signed by a duly authorized officer. Guarantor specificallyacknowledges 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 wouldnot issue Letters of Credit on behalf of any Qualified Borrower.          3. 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 orexemption, whether now or at any time hereafter in force, which may delay, prevent or otherwiseaffect the performance by Guarantor of its obligations under, or the enforcement by theAdministrative Agent of, this Guaranty. Guarantor further covenants and agrees not to set up orclaim any defense, counterclaim, offset, set-off or other objection of any kind to any action, suitor proceeding in law, equity or otherwise, or to any demand or claim that may be instituted or madeby the Administrative Agent other than the defense of the actual timely paymentand 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 assertany compulsory counterclaim, if such counterclaim is compelled under local law or rule ofprocedure, nor shall the foregoing be deemed a waiver of Guarantor’s right to assert any claimwhich would constitute a defense, setoff, counterclaim or crossclaim of any nature whatsoeveragainst Administrative Agent or any Bank in any separate action or proceeding. Guarantorrepresents, warrants and agrees that, as of the date hereof, its obligations under this Guarantyare not subject to any counterclaims, offsets or defenses of any kind against the AdministrativeAgent, the Banks or the Fronting Bank.          4. The provisions of this Guaranty are for the benefit of the Administrative Agent on behalfof the Banks and their successors and permitted assigns, and nothing herein contained shall impairas between any Qualified Borrower and the Administrative Agent the obligations of such QualifiedBorrower under the Loan Documents.          5. This Guaranty shall be a continuing, unconditional and absolute guaranty and the liabilityof Guarantor hereunder shall in no way be terminated, affected, modified, impaired or diminished byreason of the happening, from time to time, of any of the following, all without notice or thefurther consent of Guarantor:(a) 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 LoanDocuments or the invalidity or unenforceability of any of the foregoing; or(b) any extension of time that may be granted by the Administrative Agent to any QualifiedBorrower, any guarantor, or their respective successors or assigns, heirs, executors,administrators or personal representatives; or(c) any action which the Administrative Agent may take or fail to take under or in respectof any of the Loan Documents or by reason of any waiver of, or failure to enforce any ofthe rights, remedies, powers or privileges available to the Administrative Agent under thisGuaranty or available to the Administrative Agent at law, equity or otherwise, or anyaction on the part of the Administrative Agent granting indulgence or extension in any formwhatsoever; or(d) any sale, exchange, release, or other disposition of any property pledged, mortgaged orconveyed, or any property in which the Administrative Agent and/or the Banks have beengranted a lien or security interest to secure any indebtedness of any Qualified Borrower tothe Administrative Agent and/or the Banks; or(e) any release of any person or entity who may be liable in any manner for the payment andcollection of any amounts owed by any Qualified Borrower to the Administrative Agent and/or the Banks; or
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(f) the application of any sums by whomsoever paid or however realized to any amounts owing byany Qualified Borrower to the Administrative Agent and/or the Banks under the Loan Documents insuch manner as the Administrative Agent shall determine in its sole discretion; or(g) 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 ofany Qualified Borrower’s or Guarantor’s assets, insolvency, bankruptcy, assignment for the benefitof creditors, reorganization, arrangement, composition or readjustment, or the commencement ofother similar proceedings affecting any Qualified Borrower or Guarantor or any of the assets ofany of them, including, without limitation, (i) the release or discharge of any Qualified Borroweror Guarantor from the payment and performance of their respective obligations under any of theLoan Documents by operation of law, or (ii) the impairment, limitation or modification of theliability of any Qualified Borrower or Guarantor in bankruptcy, or of any remedy for theenforcement of the Guaranteed Obligations under any of the Loan Documents, or Guarantor’sliability under this Guaranty, resulting from the operation of any present or future provisions ofthe Bankruptcy Code or other present or future federal, state or applicable statute or law or fromthe decision in any court; or(h) any improper disposition by any Qualified Borrower of the proceeds of the Loans, it beingacknowledged by Guarantor that the Administrative Agent shall be entitled to honor any requestmade by any Qualified Borrower for a disbursement of such proceeds and that the AdministrativeAgent shall have no obligation to see the proper disposition by such Qualified Borrower of suchproceeds.(i) Guarantor hereby agrees that if at any time all or any part of any payment at any timereceived by the Administrative Agent from any Qualified Borrower under any of the Notes or otherLoan Documents or Guarantor under or with respect to this Guaranty is or must be rescinded orreturned by the Administrative Agent for any reason whatsoever (including, without limitation, theinsolvency, bankruptcy or reorganization of any Qualified Borrower or Guarantor), then Guarantor’sobligations hereunder shall, to the extent of the payment rescinded or returned, be deemed to havecontinued in existence notwithstanding such previous receipt by the Administrative Agent, andGuarantor’s obligations hereunder shall continue to be effective or reinstated, as the case maybe, as to such payment, as though such previous payment to the Administrative Agent had never beenmade.(j) Until this Guaranty is terminated pursuant to the terms hereof, the Guarantor (i) shall haveno right of subrogation against any Qualified Borrower or any entity comprising same by reason ofany payments or acts of performance by Guarantor in compliance with the obligations of Guarantorhereunder; (ii) hereby waives any right to enforce any
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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 ofperformance in compliance with the obligations of Guarantor hereunder; and (iii) from and afteran Event of Default (as defined in the Credit Agreement) subordinates any liability orindebtedness of any Qualified Borrower or any entity comprising same now or hereafter held byGuarantor to the obligations of each Qualified Borrower under the Loan Documents.          6. Guarantor hereby represents, warrants and covenants on its own behalf to the AdministrativeAgent with the knowledge that the Administrative Agent is relying upon the same, as follows:(a) Guarantor will be familiar with the financial condition of each Qualified Borrower;(b) Guarantor has determined that it is in its best interest to enter into this Guaranty;(c) this Guaranty is necessary and convenient to the conduct, promotion and attainment ofGuarantor’s business, and is in furtherance of Guarantor’s business purposes;(d) the benefits to be derived by Guarantor from each Qualified Borrower’s access to fundsmade possible by the Loan Documents are at least equal to the obligations of Guarantorundertaken pursuant to this Guaranty;(e) the Guarantor is solvent and has full partnership power and legal right to enter intothis Guaranty and to perform its obligations under the terms hereof and (i) Guarantor isorganized and validly existing under the laws of its state of formation, (ii) Guarantor hascomplied with all provisions of applicable law in connection with all aspects of thisGuaranty, and (iii) the person executing this Guaranty on behalf of Guarantor has all therequisite power and authority to execute and deliver this Guaranty; and(f) this Guaranty has been duly executed by Guarantor and constitutes the legal, valid andbinding obligation of Guarantor, enforceable against it in accordance with its terms exceptas enforceability may be limited by applicable insolvency, bankruptcy or other lawsaffecting creditors’ rights generally or general principles of equity whether suchenforceability 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 hereofand as the date of the making any Loan or the issuance of any Letter of Credit to or for theaccount on any Qualified Borrower.          7. Each of Guarantor and the Administrative Agent acknowledges and agrees that this Guaranty is a guaranty of payment and not of collection and enforcement inrespect of any
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obligations which may accrue to the Administrative Agent and/or the Banks from eachQualified Borrower under the provisions of any Loan Document.          8. 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.          9. Guarantor agrees, upon the written request of the Administrative Agent, to execute anddeliver to the Administrative Agent, from time to time, any modification or amendment hereto or anyadditional instruments or documents reasonably considered necessary by the Administrative Agent orits counsel to cause this Guaranty to be, become or remain valid and effective in accordance withits terms, provided, that, any such modification, amendment, additional instrument or documentshall not increase Guarantor’s obligations or diminish its rights hereunder and shall be reasonablysatisfactory as to form to Guarantor and to Guarantor’s counsel.          10. The representations and warranties of the Guarantor set forth in this Guaranty shallsurvive until this Guaranty shall terminate in accordance with the terms hereof.          11. This Guaranty together with the Credit Agreement, each Note now or hereafter executed anddelivered by any Qualified Borrower, and the other Loan Documents contain the entire agreementamong the parties with respect to the subject matter hereof and supersedes all prior agreementsrelating to such subject matter and may not be modified, amended, supplemented or discharged exceptby a written agreement signed by Guarantor and the Administrative Agent.          12. If all or any portion of any provision contained in this Guaranty shall be determined tobe invalid, illegal or unenforceable in any respect for any reason, such provision or portionthereof shall be deemed stricken and severed from this Guaranty and the remaining provisions andportions thereof shall continue in full force and effect.          13. This Guaranty may be executed in counterparts which together shall constitute the sameinstrument.          14. 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 similarwriting) and shall be addressed to such party at the address set forth below or to such otheraddress 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.
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   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: DLA Piper Rudnick Gray Cary US LLP  203 North LaSalle Street, Suite 1900  Chicago, Illinois 60601  Attention: James M. Phipps, Esq.   If to the Administrative Agent: JPMorgan Chase Bank, N.A.  707 Travis Street, 6th Floor North  Houston, Texas 77002  Attention: Susan M. Tate   and to: JPMorgan Chase Bank, N.A.  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 orfacsimile transmission, when such telex or facsimile is transmitted to the telex number orfacsimile number specified in this Section and the appropriate answerback or facsimile confirmationis received, (ii) if given by certified registered mail, return receipt requested, with first classpostage prepaid, addressed as aforesaid, upon receipt or refusal to accept delivery, (iii) if givenby a nationally recognized overnight carrier, 24 hours after such communication is deposited withsuch carrier with postage prepaid for next day delivery, or (iv) if given by any other means, whendelivered at the address specified in this Section.          15. This Guaranty shall be binding upon Guarantor and its successors and assigns and shallinure to the benefit of the Administrative Agent and its successors and assigns.          16. The failure of the Administrative Agent to enforce any right or remedy hereunder, orpromptly to enforce any such right or remedy, shall not constitute a waiver thereof, nor give riseto any estoppel against the Administrative Agent, nor excuse Guarantor from its obligationshereunder. Any waiver of any such right or remedy to be enforceable against the
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Administrative Agent must be expressly set forth in a writing signed by the Administrative Agent.17. (a) THIS GUARANTY AND THE RIGHTS AND OBLIGATIONS OF THEPARTIES HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND BE GOVERNED BY THE LAWSOF THE STATE OF NEW YORK.(b) Any legal action or proceeding with respect to this Guaranty and anyaction forenforcement of any judgment in respect thereof may be brought in the courts of the State ofNew York or of the United States of America for the Southern District of New York, and, byexecution and delivery of this Guaranty, Guarantor hereby accepts for itself and in respectof its property, generally and unconditionally, the non-exclusive jurisdiction of theaforesaid courts and appellate courts from any thereof. Guarantor irrevocably consents tothe service of process out of any of the aforementioned courts in any such action orproceeding by the mailing of copies thereof by registered or certified mail, postageprepaid, to Guarantor at the address for notices set forth herein. Guarantor herebyirrevocably waives any objection which it may now or hereafter have to the laying of venueof any of the aforesaid actions or proceedings arising out of or in connection with thisGuaranty brought in the courts referred to above and hereby further irrevocably waives andagrees not to plead or claim in any such court that any such action or proceeding broughtin any such court has been brought in an inconvenient forum. Nothing herein shall affectthe right of the Administrative Agent to serve process in any other manner permitted by lawor to commence legal proceedings or otherwise proceed against Guarantor in any otherjurisdiction.(c) EACH OF THE GUARANTOR AND THE ADMINISTRATIVE AGENT HEREBY WAIVES ITS RIGHTS TO A JURYTRIAL 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 MATERIALINDUCEMENT FOR THE ADMINISTRATIVE AGENT TO ACCEPT THIS GUARANTY AND THAT THE LOANS MADE BY THE BANKS ARE MADE IN RELIANCEUPON 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 BEFILED BY THE ADMINISTRATIVE AGENT IN COURT AS A WRITTEN CONSENT TO A NON-JURY TRIAL.(d) Guarantor hereby further covenants and agrees with the Administrative Agent thatGuarantor may be joined in any action against the Qualified Borrower in connection with theLoan Documents and that recovery may be had against Guarantor in such action or in anyindependent action against Guarantor (with respect to the Guaranteed Obligations), withoutthe Administrative Agent first pursuing or exhausting any remedy or claim
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against the Qualified Borrower or its successors or assigns. Guarantor also agrees that, in an actionbrought with respect to the Guaranteed Obligations in any jurisdiction, it shall beconclusively bound by the judgment in any such action by the Administrative Agent (whereverbrought) against any Qualified Borrower or its successors or assigns, as if Guarantor werea party to such action, even though Guarantor was not joined as a party in such action.(e) Guarantor hereby agrees to pay all reasonable expenses (including, without limitation,attorneys’ fees and disbursements) which may be incurred by the Administrative Agent inconnection with the enforcement of its rights under this Guaranty, whether or not suit isinitiated.          18. Subject to the terms of Section 5(i) hereof, this Guaranty shall terminate and be of nofurther force or effect upon the full performance and payment of the Guaranteed Obligationshereunder. Upon termination of this Guaranty in accordance with the terms of this Guaranty, theAdministrative Agent promptly shall deliver to Guarantor such documents as Guarantor or Guarantor’scounsel reasonably may request in order to evidence such termination.          19. All of the Administrative Agent’s rights and remedies under each of the Loan Documents orunder this Guaranty are intended to be distinct, separate and cumulative and no such right orremedy therein or herein mentioned is intended to be in exclusion of or a waiver of any other rightor remedy available to the Administrative Agent.
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          IN WITNESS WHEREOF, the undersigned has cause this Guaranty to be duly executed and deliveredas of the date first set forth above.      GUARANTOR: