EXHIBIT
10.56.3





CHANGE
IN TERMS AGREEMENT





THIS
CHANGE IN TERMS AGREEMENT (this "CIT ") is made by and between Heritage Bank of
Commerce, a California banking corporation ("Bank"), with its headquarters
address at 150 Almaden Boulevard, San Jose, California 95113 and Mission West
Properties,Inc., a
Maryland corporation (“Borrower”), with its principal address at 10050 Bandley
Drive, Cupertino, California 95014. This CIT is executed on August 20, 2009 and
is made effective upon the satisfaction of all of the conditions precedent set
forth herein (the "Effective Date") at San Jose, California.





RECITALS




A.                    As
of March 4, 2008, Bank and Borrower entered into certain agreements (the “March
2008 Loan Documents”) including but not limited to a Revolving Credit Loan
Agreement (the “Loan Agreement”), pursuant to which Bank agreed, subject to the
terms and conditions set forth therein, to lend up to the sum of Ten Million
Dollars ($10,000,000.00) to Borrower, and pursuant to which Borrower agreed to
repay the loan on or before June 15, 2009.




B.                    Thereafter,
pursuant to a Change in Terms Agreement dated April 17, 2008 (the “April 2008
CIT”), Bank and Borrower made certain changes to the March 2008 Loan Documents,
including but not limited to revising the Loan Agreement to provide for a
Commitment Amount (as defined in the April 2008 CIT), to Seventeen Million Five
Hundred Thousand and 00/100 Dollars ($17,500,000.00).




C.                    Thereafter,
pursuant to a Change in Terms Agreement dated June 5, 2009 (the “June 2009 CIT”)
Bank and Borrower made certain changes to the March 2008 Loan Documents,
including but to limited to revising the Loan Agreement to extend the maturity
date to September 15, 2009.




D.                    The
Termination Date (as defined in the June 2009 CIT), is September 15, 2009.
Borrower has requested, and Bank has agreed, subject to the terms and conditions
of this CIT, to extend the Termination Date to October 15, 2009.




AGREEMENT





In
consideration of the covenants, terms and conditions set forth herein, and in
consideration and for other good and valuable consideration, the parties hereto
agree as set forth below.





1.           Incorporation by
Reference.  The Recitals set forth above are true and correct
and are incorporated herein by reference in this CIT, together with the March
2008 Loan Documents, the April 2008 CIT, the June 2009 CIT and any other
documents executed by and between Bank and Borrower in connection with or after
the March 2008 Loan Documents (sometimes, collectively, the “Loan Documents”).
All capitalized terms not defined herein shall have the meaning given in the
Loan Documents.




2.           Amendment of Definition of
Termination Date.  The definition of “Termination Date” in the
Loan Agreement is hereby deleted and replaced by the following:




“‘Termination
Date’ shall mean October 15, 2009.”




3.           Conditions Precedent.
The effectiveness of this CIT and Bank’s obligations hereunder are conditioned
upon the satisfaction of each and all of the following conditions on or before
September 15, 2009:




(a)
            Borrower
      shall have executed and delivered this CIT to Bank;
  and




(b)
            Borrower
      shall have paid the loan extension fee of One Thousand and 00/100 Dollars
      ($1,000.00) to Bank.




4.           Legal
Effect.  Except as specifically provided herein, all of the
terms and conditions of the Loan Documents remain in full force and
effect.




5.           Integration. This CIT
is an integrated agreement. Except as specifically set froth herein, and except
for the Loan Documents as modified hereby, it supersedes all prior
representations and agreements, if any, between the parties to this CIT. This
CIT and the Loan Documents as modified hereby contain the entire and only
understanding of the parties with respect to the subject matter hereof and
thereof, and may not be altered, amended or extinguished, except by a writing
signed by all parties.





IN WITNESS WHEREOF, the parties hereto
have executed and entered into this CIT effective as of the Effective Date first
written above.


BANK:HERITAGE
      BANK OF COMMERCEa
      California banking corporationBy:
                /s/ Roxanne VaneRoxanne
      VaneIts:
                Senior
      Vice President / Regional ManagerBORROWER:MISSION
      WEST PROPERTIES, INC.a
      Maryland corporationBy:
                /s/ Raymond V. MarinoRaymond
      V. MarinoIts:
                President
      and Chief Operating Officer