Exhibit 10.29

THIS CONTRIBUTION AGREEMENT (this “Agreement”) is made as of May 10, 2011, by
and among KBS ACQUISITION HOLDINGS, LLC, a Delaware limited liability company
(“KBS Holdings”), and KBS ACQUISITION SUB, LLC, a Delaware limited liability
company (“KBS Sub”). Except as otherwise specified, capitalized terms used but
not defined herein have the respective meanings set forth in the Amended and
Restated Master Repurchase Agreement (the “Repurchase Agreement”), dated as of
the date hereof, between KBS GKK Participation Holdings I, LLC (“KBS GKK I”), as
Seller, and Goldman Sachs Mortgage Company, as Buyer.
WHEREAS, this Agreement relates to:
(a) that certain Loan Agreement dated as of April 1, 2008, between the borrowers
named therein (collectively, “Borrower”) and Goldman Sachs Mortgage Company
(“Goldman”), as successor-in-interest to Goldman Sachs Commercial Mortgage
Capital, L.P., Citicorp North America, Inc. (“Citi”) and SLG Stars Mortgage Loan
LLC (“SLG Mortgage”), as successor-in-interest to SL Green Realty Corp. (“SL
Green”), collectively, as the “Senior Lender” (as amended by that certain
Amendment to Loan Agreement dated as of August 22, 2008, that certain Second
Amendment to Loan Agreement dated as of March 9, 2010, that certain letter Re:
Omnibus Extension of Loan Agreements dated as of March 13, 2011, (the “First
Extension Letter”), that certain letter Re: Omnibus Extension of Loan Agreements
dated as of April 15, 2011, (the “Second Extension Letter”), that certain letter
Re: Omnibus Extension of Loan Agreements dated as of April 29, 2011, (the “Third
Extension Letter”), and that certain letter Re: Omnibus Extension of Loan
Agreements dated as of May 10, 2011 (the “Fourth Extension Letter”), the “Senior
Loan Agreement”), whereby Senior Lender made a loan to Borrower in the original
principal amount of $250,000,000 (the “Senior Loan”), which Senior Loan is now
evidenced by (1) that certain Amended and Restated Promissory Note A-1 made by
Borrower to Goldman in the original principal amount of $120,157,427.31 (the
“Goldman Senior Note”), (2) that certain Amended and Restated Promissory Note
A-2 made by Borrower to Citi in the original principal amount of $93,455,236.35
(the “Citi Senior Note”), and (3) that certain Amended and Restated Promissory
Note A-3 made by Borrower to SLG Mortgage in the original principal amount of
$35,697,282.81 (the “SLG Senior Note”; together with the Goldman Senior Note and
the Citi Senior Note, the “Senior Notes”), and secured by, among other things,
certain mortgages made by the Borrower in favor of Senior Lender (collectively,
the “Senior Mortgages”), which Senior Mortgages encumber the real property more
particularly described in the Senior Loan Agreement (collectively, the
“Premises”);
(b) that certain Junior Mezzanine Loan Agreement dated as of August 22, 2008,
between GKK Stars Junior Mezz 2 LLC (“Junior Mezzanine Borrower”), as borrower,
and Goldman, Citi and SLG Stars Mezz Loan LLC, as successor-in-interest to SL
Green (“SLG Mezz”), collectively as the “Junior Mezzanine Lender” (as amended by
that certain Amendment to Junior Mezzanine Loan Agreement dated as of August 22,
2008, the First Extension Letter, the Second Extension Letter, the Third
Extension Letter, and the Fourth Extension Letter, the “Junior Mezzanine Loan
Agreement,” and together with the Senior Loan Agreement, the “Loan Agreements”),
whereby Junior Mezzanine

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Lender is the owner and holder of a loan to Junior Mezzanine Borrower in the
original principal amount of $99,329,673.13 (the “Junior Mezzanine Loan” and
together with the Senior Loan, the “Loans”), which Junior Mezzanine Loan is
evidenced by (1) that certain Mezzanine Promissory Note A-1 (Junior Mezzanine
Loan) made by Junior Mezzanine Borrower to Goldman in the original principal
amount of $47,872,931.46 (the “Goldman Junior Mezzanine Note”), (2) that certain
Mezzanine Promissory Note A-2 (Junior Mezzanine Loan) made by Junior Mezzanine
Borrower to Citi in the original principal amount of $37,234,286.92 (the “Citi
Junior Mezzanine Note”), and (3) that certain Mezzanine Promissory Note A-3
(Junior Mezzanine Loan) made by Junior Mezzanine Borrower to SLG Mezz in the
original principal amount of $14,222,454.75 (the “SLG Mezz Junior Mezzanine
Note”; together with the Goldman Junior Mezzanine Note and the Citi Junior
Mezzanine Note, the “Junior Mezzanine Notes” and together with the Senior Notes,
the “Notes”), and secured by, among other things, a Pledge and Security from
Junior Mezzanine Borrower pursuant to which Junior Mezzanine Lender is granted a
first priority security interest in the direct ownership interests of Junior
Mezzanine Borrower in the Senior Mezzanine Borrowers (collectively, the “Junior
Pledge Agreement”);
WHEREAS, (a) SLG Mortgage, Goldman and Citi entered into that certain Co-Lender
Agreement dated as of August 22, 2008, relative to the Senior Loan (the “Senior
Loan Co-Lender Agreement”), and (b) SLG Mezz, Goldman and Citi entered into that
certain Co-Lender Agreement dated as of August 22, 2008 (the “Junior Mezzanine
Co-Lender Agreement,” and together with the Senior Loan Co-Lender Agreement, the
“Co-Lender Agreements”);
WHEREAS, Goldman, Citi and SLG Mortgage, and SLG Mezz, collectively in their
individual capacities as “Senior Lender,” “Senior Mezzanine Lender,” and “Junior
Mezzanine Lender” entered into that certain Intercreditor Agreement, dated as of
August 22, 2008 (the “Intercreditor Agreement”);
WHEREAS, pursuant and subject to the terms and conditions of that certain
Assignment and Assumption Agreement dated May 10, 2011, by and between SLG
Mortgage and SLG Mezz (“SLG Assignors”), as assignors, and KBS GKK I, as
assignee, SLG Assignors assigned, and KBS GKK I assumed, the SLG Mortgage Senior
Note and the SLG Mezz Junior Mezzanine Note, and SLG Assignors' right, title and
interest in and to the Loans, the Loan Agreements, the other Loan Documents, the
Co-Lender Agreements and the Intercreditor Agreement (collectively, the
“Assigned Interests”);
WHEREAS, pursuant and subject to the terms and conditions of that certain
Contribution Agreement dated of even date herewith, by and between KBS GKK I and
KBS Holdings, KBS GKK I assigned, and KBS Holdings assumed, the Assigned
Interests; and
WHEREAS, KBS Holdings wishes to contribute and convey the Assigned Interests,
and KBS Holdings' obligations under the Co-Lender Agreements and the

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Intercreditor Agreement (the “Obligations”) to KBS Sub, and KBS Sub wishes to
accept the Assigned Interests, and assume the Obligations.
NOW, THEREFORE, the parties agree as follows:
ARTICLE I
THE CONTRIBUTION
SECTION 1.01    Contribution of the Assigned Interests. On the terms and subject
to the conditions and other provisions set forth in this Agreement, KBS Holdings
hereby contributes, assigns, transfers, conveys and delivers to KBS Sub as a
contribution to KBS Sub's capital all of its right, title and interest in and to
the Assigned Interests (the “Contribution”), and KBS Sub hereby accepts the
Contribution.
SECTION 1.02.    Assignment and Assumption of Participation Obligations. On the
terms and subject to the conditions and other provisions set forth in this
Agreement, KBS Holdings hereby assigns, transfers, conveys and delivers to KBS
Sub, and KBS Sub hereby assumes, and agrees to observe and perform all of the
covenants applicable to, the Obligations (the “Assumption”).
SECTION 1.03.    Acknowledgement of Consideration. Each of KBS HOLDINGS and KBS
Sub hereby acknowledges that the Contribution and Assumption are made in
consideration of an increase in the equity value of KBS Holdings' ownership
interest in KBS Sub, and each of KBS Holdings and KBS Sub hereby acknowledges
the sufficiency of such consideration.
SECTION 1.04.    Title. Title to the Assigned Interests shall pass to KBS Sub on
the date of this Agreement.
ARTICLE II
CONDITIONS OF THE CONTRIBUTION
SECTION 2.01.    Conditions Precedent to the Obligations of KBS Sub and KBS
Holdings. The obligations of KBS Sub and KBS Holdings hereunder are subject to
the satisfaction of each of the following conditions:
(a)This Agreement has been duly authorized by each of KBS Sub and KBS Holdings,
and all necessary limited liability company action has been taken and all
necessary governmental approvals, if any, have been obtained with respect to
this Agreement by each of KBS Sub and KBS Holdings.

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ARTICLE III
REPRESENTATIONS AND WARRANTIES
SECTION 3.01.    Representations of KBS Sub. As of the date hereof, KBS Sub
represents and warrants as follows:
(a)It (i) is a limited liability company duly formed, validly existing and in
good standing under the laws of Delaware, (ii) is duly qualified to do business
as a foreign limited liability company and is in good standing under the laws of
each jurisdiction where the character of its property, the nature of its
business or the performance of its obligations under the Transaction Documents
make such qualification necessary, except to the extent that the failure to so
qualify is not reasonably likely to result in a Material Adverse Effect, and
(iii) has all power and authority and all governmental licenses, authorizations,
consents and approvals required to carry on its business as now conducted and as
presently proposed to be conducted and for the purposes of the transactions
contemplated by this Agreement and the other Transaction Documents.
(b)It has all requisite power and authority to execute, deliver and perform this
Agreement and to carry out the provisions hereof. Its execution, delivery and
performance of this Agreement have been duly authorized by all necessary action
on its part and requires no action by or in respect of, or filing with, any
Governmental Authority which has not been obtained.
(c)This Agreement has been duly executed and delivered by it and constitutes its
legal, valid and binding obligation, enforceable against it in accordance with
the Agreement's terms, except as the same may be limited by (i) applicable
bankruptcy, insolvency, reorganization or similar laws affecting the enforcement
of creditors rights and (ii) general principles of equity.
(d)There is no action, suit, investigation or proceeding pending or, to its
knowledge, threatened against it before any court or arbitrator or Governmental
Authority that would materially adversely effect its financial condition,
business, assets or operations or which in any manner draws into question the
validity or enforceability of this Agreement or any other Transaction Document
or its ability to perform its obligations under the Transaction Documents.
(e)The execution, delivery and performance by it of this Agreement does not
contravene, or constitute a default under, any Requirement of Law with respect
to it or any contractual obligation with respect to it or result in the creation
or imposition of any Lien on any property of it (except for Liens permitted
under the Repurchase Agreement).
(f)The Contribution made pursuant to this Agreement is intended to constitute a
valid contribution of the Assigned Interests to KBS Sub and immediately

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upon contribution and conveyance hereunder KBS Sub shall have good title
thereto, enforceable against creditors of, and purchasers from, KBS Holdings.
(g)The Contribution and Assumption are made in good faith and without intent to
hinder, delay or defraud creditors of KBS Holdings or KBS Sub.
(h)Both before and after giving effect to the Contribution and Assumption, it is
solvent within the meaning of the Bankruptcy Code and is not the subject of any
voluntary or involuntary case or proceeding seeking liquidation, reorganization
or other relief with respect to itself or its debts under any bankruptcy or
insolvency law and no Act of Insolvency has occurred with respect to it.
(i)All of its issued and outstanding limited liability company interests are
owned by KBS Holdings, all of which limited liability company interests have
been validly issued, are fully paid and non-assessable and are owned of record
by KBS Holdings. It has no subsidiaries and owns no capital stock of, or other
equity interest in, any other Person.
(j)Other than its organizational documents, the Transaction Documents or any
other agreement entered into in connection with the execution of the Repurchase
Agreement, it is not a party to any contract or agreement of any kind or nature
and it is not subject to any obligations or liabilities of any kind or nature in
favor of any third party. It has not engaged in any activities since its
formation (other than those incidental to its formation, the execution of the
Transaction Documents to which it is a party and the performance of the
activities referred to in or contemplated by such agreements).
(k)It is not (i) in violation of its organizational documents, (ii) in violation
of any Requirement of Law or (iii) in violation of any contractual obligation.
SECTION 3.02.    Representations of KBS Holdings. As of the date hereof, KBS
Holdings represents and warrants as follows:
(a)It has been duly formed and is validly existing as a limited liability
company in good standing under the laws of the State of Delaware, with corporate
power under the laws of such state to execute and deliver this Agreement and the
other Transaction Documents to which it is a party and to perform its
obligations hereunder and thereunder, and is duly qualified and in good standing
to do business as a foreign limited liability company in each jurisdiction where
the character of its properties or the nature of its business makes such
qualification necessary and where the failure to do so would have a Material
Adverse Effect.
(b)This Agreement has been duly authorized, executed and delivered on its behalf
and, assuming due authorization, execution and delivery by the other party
thereto, this Agreement is a valid and legally binding agreement of KBS
Holdings, enforceable against it in accordance with the Agreement's terms,
except as the same may

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be limited by (i) applicable bankruptcy, insolvency, reorganization or similar
laws affecting the enforcement of creditor rights and (ii) general principles of
equity.
(c)There are is no consent, approval, authorization, order, registration or
qualification of or with any Governmental Authority having jurisdiction over it
which is required for the execution, delivery and performance of this Agreement
(except to the extent that the failure to obtain such consent, approval,
authorization, order, registration or qualification is not reasonably likely to
result in a Material Adverse Effect).
(d)There are no actions, suits, investigations or proceedings pending or, to its
knowledge after reasonable inquiry, threatened against it before any
Governmental Authority which question the validity or enforceability of this
Agreement or any action taken or to be taken pursuant hereto, or which, if
adversely determined, are reasonably likely to materially impair its ability to
perform its obligations under this Agreement.
(e)Its execution, delivery and performance of this Agreement will not conflict
with or result in a breach of any of the terms or provisions of, or constitute a
default under, or result in the creation or imposition of any lien, charge or
encumbrance upon any of its property or assets pursuant to the terms of any
indenture, mortgage, deed of trust, loan agreement, guarantee, lease financing
agreement or other similar agreement or instrument under which it is a debtor or
guarantor (except to the extent that such conflict, breach, creation or
imposition is not reasonably likely to result in a Material Adverse Effect) nor
will such action result in a violation of any provision of applicable law or
regulation (except to the extent that such violation is not reasonably likely to
result in a Material Adverse Effect) or of the provisions of its organizational
documents.
(f)The Contribution made pursuant to this Agreement is intended to constitute a
valid contribution of the Assigned Interests to KBS Sub and immediately upon
contribution and conveyance hereunder KBS Sub shall have good title thereto,
enforceable against creditors of, and purchasers from, KBS Holdings. KBS
Holdings shall have no remaining property interest in the Assigned Interests
sold to KBS Sub.
(g)The Contribution and Assumption are made in good faith and without intent to
hinder, delay or defraud creditors of KBS Holdings or KBS Sub.
(h)Immediately prior to the Contribution and Assumption contemplated hereby, it
has good and valid title to the Assigned Interests, free and clear of all Liens
and rights of others, except Liens permitted under the Repurchase Agreement.
ARTICLE IV
COVENANTS
SECTION 4.01.    Covenants of the Parties.

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(a)Compliance with Laws, etc. Each of KBS Sub and KBS Holdings will comply in
all material respects with all applicable Requirements of Law, except where the
necessity of compliance therewith is contested in good faith by appropriate
proceedings and where such noncompliance would not materially and adversely
affect its business, financial condition, operations or properties or its
ability to perform its obligations under the Transaction Documents to which it
is a party.
(b)Notice of Proceedings. Promptly upon becoming aware thereof, each of KBS Sub
and KBS Holdings agrees to give the other party to this Agreement and both
Citicorp Financial Products Inc. and Goldman Sachs Mortgage Company
(collectively, “Buyers”) written notice of the commencement or existence of any
proceeding by or before any Governmental Authority against or affecting it which
is reasonably likely to have a material adverse effect on its financial
condition, business, assets or operations or its ability to perform its
obligations under this Agreement or the Transaction Documents to which it is a
party.
(c)Further Assurances. Each of KBS Sub and KBS Holdings agrees from time to
time, at its expense, promptly to execute and deliver all further instruments
and documents, and to take all further reasonable actions that may be reasonably
necessary or desirable to perfect, protect, or more fully evidence the
contribution, conveyance and acceptance of the Contribution and Assumption under
this Agreement, or to enable a party to this Agreement or its assignee to
exercise and enforce its respective rights and remedies under this Agreement.
ARTICLE V
MISCELLANEOUS
SECTION 5.01.    Entire Agreement. This Agreement and the other agreements
specifically referenced herein constitute the entire agreement among the parties
hereto and supersede any prior understandings, agreements, or representations by
or among the parties hereto, written or oral, to the extent they related in any
way to the subject matter hereof.
SECTION 5.02.    Succession and Assignment. This Agreement will be binding upon
and inure to the benefit of the parties hereto and their respective successors
and permitted assigns. The parties hereto may not otherwise assign either this
Agreement or any of their respective rights, interest, or obligations hereunder
without the prior written approval of the other parties and Buyers.
SECTION 5.03.    Counterparts. This Agreement may be executed in separate
counterparts, each of which will be deemed an original but all of which together
will constitute one and the same instrument. Delivery of an executed counterpart
of a signature page of this Agreement by facsimile transmission or electronic
transmission (in pdf format) shall be as effective as delivery of a manually
executed counterpart of this Agreement.

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SECTION 5.04.    Headings. The section headings contained in this Agreement are
inserted for convenience only and will not affect in any way the meaning or
interpretation of this Agreement.
SECTION 5.05.    Governing Law. THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE DOMESTIC LAWS OF THE STATE OF NEW YORK.
SECTION 5.06.    Amendments and Waivers. No amendment of any provision of this
Agreement shall be valid unless the same will be in writing and signed by each
of the parties hereto. No waiver by any party hereto of any default,
misrepresentation, or breach of warranty or covenant hereunder, whether
intentional or not, will be deemed to extend to any prior or subsequent default,
misrepresentation, or breach of warranty or covenant hereunder or affect in any
way any rights arising by virtue of any prior or subsequent such occurrence.
SECTION 5.07.    Severability. Any term or provision of this Agreement that is
invalid or unenforceable in any situation in any jurisdiction will not affect
the validity or enforceability of the remaining terms and provisions hereof or
the validity or enforceability of the offending term or provision in any other
situation or in any other jurisdiction.
SECTION 5.08.    Construction. The language used in this Agreement will be
deemed to be the language chosen by the parties hereto to express their mutual
intent, and no rule of strict construction will be applied against any party.
SECTION 5.09.    Nonpetition Covenants. Each of KBS Sub and KBS Holdings hereby
covenants and agrees that, prior to the date which is one year and one day after
the payment in full of all of the Repurchase Obligations, it will not institute
against, or join any other Person in instituting against, KBS Sub any
bankruptcy, reorganization, arrangement, insolvency or liquidation proceedings
or other similar proceeding under the laws of the United States or any state of
the United States. The provisions of this Section 5.09 shall survive the
termination of this Agreement. Buyers are an intended third party beneficiary of
this Section.

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IN WITNESS WHEREOF, the parties hereto have duly executed this
Agreement as of the date first above written.
KBS ACQUISITION HOLDINGS, LLC,
a Delaware limited liability company
    
By:    KBS GKK PARTICIPATION HOLDINGS I, LLC,
a Delaware limited liability company,
its sole member

By:    KBS DEBT HOLDINGS, LLC,
a Delaware limited liability company,
its sole member

By:    KBS LIMITED PARTNERSHIP,
a Delaware limited partnership,
its manager

By:    KBS REAL ESTATE INVESTMENT TRUST, INC.,
a Maryland corporation,
its sole general partner

By:    /s/ David E. Snyder
David E. Snyder
Chief Financial Officer

[Signatures continue on next page.]

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KBS ACQUISITION SUB, LLC,
a Delaware limited liability company
    
By:    KBS ACQUISITION HOLDINGS, LLC,
a Delaware limited liability company,
its sole member
    
By:    KBS GKK PARTICIPATION HOLDINGS I, LLC,
a Delaware limited liability company,
its sole member

By:    KBS DEBT HOLDINGS, LLC,
a Delaware limited liability company,
its sole member

By:    KBS LIMITED PARTNERSHIP,
a Delaware limited partnership,
its manager

By:    KBS REAL ESTATE INVESTMENT TRUST, INC.,
a Maryland corporation,
its sole general partner

By:    /s/ David E. Snyder
David E. Snyder
Chief Financial Officer

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