EXHIBIT 10.63


                        THIRD AMENDMENT TO AGREEMENT FOR
                PURCHASE AND SALE AND JOINT ESCROW INSTRUCTIONS
                -----------------------------------------------

          This Third Amendment to Agreement of Purchase and Sale and Joint
Escrow Instructions (this "Third Amendment") is made as of September 19, 1997 by
and between Kilroy Realty, L.P., a Delaware limited partnership ("Buyer") and
Mission Square Partners, a California general partnership ("Seller") with
respect to the following:

                               R E C I T A L S :
                               - - - - - - - - 

          A.  Seller and Buyer entered into that certain Agreement of Purchase
and Sale and Joint Escrow Instructions providing for the sale of 3750 University
Avenue, Riverside, California as amended by that certain First Amendment and
that certain Second Amendment to the same (collectively, the "Agreement");

          B.  Buyer and Seller anticipate that additional time will be required
to complete Buyer's review of the Property;

          C.  Seller and Buyer desire to amend the Agreement to provide for such
additional time.

          NOW THEREFORE, in consideration of the mutual covenants and agreements
herein contained and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, Seller and Buyer hereby agree as
follows:

                              A G R E E M E N T :
                              - - - - - - - - -  

          1. Notwithstanding anything in the agreement to the contrary, the
contingency date provided for in the Agreement is hereby extended to September
22, 1997.

          2.  Seller acknowledges that, as provided for in the First Amendment
to the Agreement, Buyer shall have until September 25, 1997 to terminate the
Agreement if it has not obtained the Met Consent on or before such date.

          3.  Except as set forth in this Third Amendment, the provisions of the
Agreement remain unmodified and in full force and effect.  If any provision of
this Third Amendment conflicts with any provision of the Agreement, the
provisions of this Third Amendment shall prevail.

          4.  Any capitalized terms which are not defined in this Third
Amendment shall have the meaning provided for in the Agreement.

 
          5.  This Third Amendment may be signed in counterparts, including
facsimile counterparts, which, when signed by both Buyer and Seller, shall
constitute a binding agreement.

          IN WITNESS WHEREOF, the parties have executed this Third Amendment as
of the date first written above.

     "Buyer"                  KILROY REALTY, L.P.,
                              a Delaware limited partnership

                              By:  /s/ Nadine K. Kirk
                                 ----------------------------------------------
                                 Name:  Nadine K. Kirk
                                      -----------------------------------------
                                 Title:  V.P. - Legal
                                       ----------------------------------------

     "Seller"                 MISSION SQUARE PARTNERS,
                              a California general partnership

                              By: The Betty L. Hutton Title Holding Company,
                                  Inc., (formerly known as The Betty L. Hutton
                                  Company),
                                  its general partner

                              By:  /s/ Thomas C. Parker
                                 ----------------------------------------------
                                 Name:  Thomas C. Parker
                                      -----------------------------------------
                                 Title:  C.E.O.
                                       ----------------------------------------

                              By: BB&K Mission Square Partners, a California
                                  general partnership,
                                  its general partner

                                  By:  /s/ Christopher L. Carpenter
                                     ------------------------------------------
                                     Name:  Christopher L. Carpenter
                                          -------------------------------------
                                     Title:  Partner
                                           ------------------------------------

Acknowledgment by Escrow Holder:
- ------------------------------- 

          First American Title Insurance Company hereby acknowledges the terms
of this Third Amendment.

Dated:__________________, 1997    FIRST AMERICAN TITLE INSURANCE COMPANY

                                  By:_________________________________________
                                     Its Authorized Agent


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