<PAGE>

                                                                    Exhibit 10.5

                       FOURTH AMENDMENT TO LOAN AGREEMENT

     THIS FOURTH AMENDMENT TO LOAN AGREEMENT (this "Amendment"), dated as of
December 23, 2002, is entered into by and among:

          (1)  CATELLUS FINANCE 1, L.L.C., a Delaware limited liability company
     ("Borrower");

          (2)  LASALLE BANK NATIONAL ASSOCIATION, f/k/a LaSalle National Bank,
     as trustee for the registered Holders of Prudential Mortgage Capital
     Company I, LLC, Commercial Mortgage Pass-Through Certificates, Series
     1998-1 ("Lender");

          (3)  Each of the certificateholders listed in Schedule I attached
     hereto (collectively, the "Certificateholders") comprising all of the
     holders of Certificates as defined in that certain Trust and Servicing
     Agreement dated as of November 11, 1998, by and among Prudential Mortgage
     Capital Company I, LLC, as Depositor, The Prudential Insurance Company of
     America, as Servicer, ABN AMRO Bank N.V., as Fiscal Agent, and LaSalle
     National Bank, as Trustee (the "Trust and Servicing Agreement"); and

          (4)  THE PRUDENTIAL INSURANCE COMPANY OF AMERICA, as servicer under
     the Trust and Servicing Agreement (in such capacity, "Servicer").

                                    RECITALS

     A.   Reference is made to that certain loan agreement dated as of October
26, 1998 (the "Original Loan Agreement") between Borrower and Prudential
Mortgage Capital Company, Inc., a Delaware corporation ("Prudential"),
predecessor-in-interest to Lender, as amended by that certain First Amendment to
Loan Agreement dated as of January 11, 2001, by and among Borrower, Lender, the
Certificateholders, and Servicer (the "First Amendment") and that certain Second
Amendment to Loan Agreement dated as of February 8, 2001 (the "Second
Amendment"), that certain Second [sic] Amendment to Loan Agreement dated as of
August 27, 2002 (the "Third Amendment") (the Original Loan Agreement as amended
by the First Amendment, the Second Amendment and the Third Amendment and the
same may hereinafter be consolidated, extended, modified, amended and/or
restated or renewed from time to time, collectively, the "Loan Agreement").
Pursuant to the terms of the Original Loan Agreement, Prudential agreed to
extend a loan (the "Loan"), evidenced by that certain promissory note dated
October 26, 1998, in the original principal amount of THREE HUNDRED
SEVENTY-THREE MILLION AND 00/100 DOLLARS ($373,000,000.00).

     B.   Prudential assigned all of its right, title and interest under the
Loan to Prudential Mortgage Capital Company I, LLC, which in turn assigned all
of its right, title and interest under the Loan to Lender in accordance with the
terms and provisions of the Trust and Servicing Agreement.

     C.   In connection with the closing of the Loan, Borrower pledged to
Prudential as collateral for the Loan, among other things, that certain real
property comprising a portion of the

<PAGE>

Property Pool identified as OK1090404, Oklahoma City, Oklahoma in Exhibit A to
the Loan Agreement (the "Oklahoma Property"); which property is more
specifically described on Exhibit A attached hereto.

     D.   Borrower has requested Lender, the Certificateholders and the Servicer
to amend the Loan Agreement to permit Borrower to substitute a property in place
of the Oklahoma Property on terms other than those contained in the Loan
Agreement and in connection therewith to release the Oklahoma Property from the
lien of the Loan Documents, including the applicable mortgage, assignment of
leases and rents and UCC-1 financing statements.

     E.   Lender, the Certificateholders, and the Servicer are willing so to
amend the Loan Agreement and release the Oklahoma Property from the lien of the
Loan Documents upon the terms and subject to the conditions set forth herein.

     F.   Borrower, Lender, the Certificateholders, and the Servicer also desire
to amend the Third Amendment to correct a scrivener's error made with respect to
the Third Amendment whereby despite the existence of a Second Amendment to the
Loan Agreement, the Third Amendment to the Loan Agreement was also titled
"Second Amendment to Loan Agreement".

                                    AGREEMENT

     NOW, THEREFORE, in consideration of the above recitals and for other good
and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, Borrower, Lender, the Certificateholders and the Servicer hereby
agree as follows:

     1.   Definitions, Interpretation. All capitalized terms defined above and
elsewhere in this Amendment shall be used herein as so defined. Unless otherwise
defined herein, all other capitalized terms used herein shall have the
respective meanings given to those terms in the Loan Agreement, as amended by
this Amendment.

     2.   Amendments to Third Amendment. The Third Amendment is hereby amended
as follows: (i) the title of the Third Amendment shall be "Third Amendment to
Loan Agreement" and all references to "Second" within the Third Amendment shall
be amended to "Third"; and (ii) the definition of Original Loan Agreement
contained in the Third Amendment shall be modified to include a reference to the
Second Amendment.

     3.   Deliveries and Amendment to Loan Agreement

          (a) Subject to the satisfaction of the conditions set forth in
     Paragraph 6 below, the following shall occur on the Effective Date (as
     defined in Paragraph 6 below):

                (i) Lender shall deliver or cause the Servicer to deliver to
     Borrower (1) a Release of Mortgage, Assignment of Leases and Rents,
     Security Agreement and Fixture Filing in the form of Exhibit B hereto with
     respect to the Oklahoma Property, duly executed by Lender and appropriately
     notarized; (2) a Release of Assignment of Leases and Rents in the form of
     Exhibit C hereto with respect to the Oklahoma Property, duly

                                        2

<PAGE>

     executed by Lender and appropriately notarized; and (3) a termination of
     UCC Financing Statement in the form of Exhibit D attached hereto relating
     to the Oklahoma Property, duly executed by Lender.

                (ii) Exhibit A and Schedule 1 of the Loan Agreement shall be
     amended by deleting therefrom the Oklahoma Property.

          (b) Notwithstanding the foregoing, the release of the Oklahoma
     Property shall not constitute a release of Borrower's indemnification
     obligations under the Loan Agreement or under the other Loan Documents as
     to any matters or claims which occurred or relate to any matters or claims
     which occurred on or before the Effective Date with respect to the Oklahoma
     Property and such obligations shall survive the release of the Oklahoma
     Property from the Property Pool.

     4.   Representations and Warranties of Borrower. Borrower hereby represents
and warrants to Lender, the Certificateholders and Servicer that the following
are true and correct on the date of this Amendment and that, after giving effect
to the amendment set forth in Paragraphs 2 and 3 above, the following will be
true and correct on the Effective Date:

          (a)  The representations and warranties of Borrower set forth in
     Article V of the Loan Agreement and in the other Loan Documents are true
     and correct in all material respects as if made on such date (except for
     representations and warranties expressly made as of a specified date, which
     shall be true as of such date);

          (b)  No Default or Event of Default has occurred and is continuing;

          (c)  All of the Loan Documents are in full force and effect;

          (d)  The fair market value of all the Properties securing the Loan as
     of the Closing Date as listed on Schedule 1 to the Loan Agreement was
     $522,829,999, and, to Borrower's knowledge, the current fair market value
     of all the Properties currently securing the Loan as of the date hereof has
     not materially and adversely changed from the fair market values as of the
     Closing Date; and

          (e)  The current value of the Oklahoma Property as of the date hereof
     is not more than $3,400,000.00 per an appraisal dated November 26, 2002.

(Without limiting the scope of the term "Loan Documents," Borrower expressly
acknowledges in making the representations and warranties set forth in this
Paragraph 4 that, on and after the date hereof, such term includes this
Amendment.)

     5.   Representations of Servicer to Lender and Certificateholders. Servicer
hereby represents and warrants to Lender and the Certificateholders that the
following are true and correct on the date of this Amendment:

          (a)  To Servicer's knowledge, the outstanding principal balance of the
     Loan as of December 5, 2002 is Three Hundred Fifty-Two Million Nine Hundred
     Forty-Six Thousand Five Hundred Thirty-One and 77/100 dollars
     ($352,946,531.77);

                                        3

<PAGE>

          (b)  Servicer is not receiving any loan payments or fees from Borrower
     in connection with the release of the Oklahoma Property and this Amendment
     other than for amounts intended to reimburse Servicer for costs and
     expenses in handling the transaction; and

          (c)  The release of the Oklahoma Property will not change the
     Servicer's payment expectations with respect to the Loan.

     6.   Effective Date. The amendments effected by Paragraph 3 above shall
become effective (the "Effective Date") upon satisfaction and receipt by Lender,
the Certificateholders and Servicer of the following matters, each in form and
substance satisfactory to Lender, the Certificateholders and Servicer:

          (a)  This Amendment duly executed by Borrower, Lender, the
     Certificateholders and Servicer;

          (b)  The Agreement of Catellus Development Corporation and Plato REIT,
     LLC, as guarantors under the Loan, duly executed by the guarantors and in
     the form of Exhibit E hereto (the "Reaffirmation");

          (c)  Cash in the amount of $4,000,000.00 (the "Interim Cash Reserve
     Deposit"). The Interim Cash Reserve Deposit shall be held and applied by
     the Lender in accordance with Paragraph 7 below;

          (d)  An opinion of Borrower's legal counsel dated as of the Effective
     Date in form and substance acceptable to Lender, which shall cover, without
     limitation, the following matters:

               (i)    the due organization, valid legal existence and good
     standing of Borrower, Catellus Development Corporation, and Plato REIT,
     LLC;

               (ii)   the due authorization, execution, delivery, validity,
     binding effect and enforceability of this Amendment and the Reaffirmation
     in accordance with their terms;

               (iii)  the existence of, or the nonexistence of, any requirement
     for any consent of any other party in connection with the execution,
     delivery or performance of the this Amendment and the Reaffirmation;

               (iv)   the fact that the Amendment, the Reaffirmation and the
     execution thereof and the performance of the obligations thereunder do not
     conflict with or violate any applicable laws, agreements or restrictions;
     and

               (v)    such other matters incident to this Amendment as Lender
     may reasonably request;

          (d)  An opinion of counsel (obtained at the expense of Borrower) to
     the effect that this Amendment and the release of the Oklahoma Property
     will not cause either the

                                        4

<PAGE>

     Lower-Tier REMIC or the Upper Tier REMIC (as such terms are defined in the
     Trust and Servicing Agreement) to fail to qualify as REMIC for federal
     income tax purposes;

          (e)  Payment of all fees and expenses payable to Lender, the
     Certificateholders and Servicer, including all attorneys' fees and
     expenses;

          (f)  Confirmation from the Rating Agencies that the release of the
     Oklahoma Property and the entering into of this Amendment will not result
     in a downgrade, qualification or withdrawal of the ratings of the
     securities held by the Certificateholders; and

          (g)  Such other evidence as Lender, the Certificateholders and
     Servicer may reasonably request to establish the accuracy and completeness
     in all material respects of the representations and warranties and the
     compliance with the terms and conditions contained in this Amendment and
     the other Loan Documents.

     7.   Interim Cash Reserve Deposit Account.

          (a)  Borrower shall deposit (or cause to be deposited) with Lender (or
     at Lender's election, Servicer) into a segregated account owned and
     established by Lender and under the exclusive control of Lender, and at
     Lender's election, Servicer (the "Interim Cash Reserve Deposit Account"),
     an amount equal to the Interim Cash Reserve Deposit. All amounts held in
     the Interim Cash Reserve Deposit Account shall accrue interest for the
     benefit of Borrower, at the customary rate of interest earned by Lender (or
     Servicer) on short term funds and all such interest shall be added to and
     become a part of the Interim Cash Reserve Deposit. Borrower shall pay to
     Lender (or its Servicer) the administrative costs associated with
     investing, administering or otherwise providing for interest on the amounts
     so deposited. The Interim Cash Reserve Deposit shall be applied in
     accordance with the provisions of subparagraphs (b) and (e) of this
     Paragraph 7, as applicable.

          (b)  The Interim Cash Reserve Deposit shall be refunded to Borrower
     provided that on or before __________, 2003 [insert the date that is six
     (6) months after the Effective Date] (the "Oklahoma Property Substitution
     or Partial Defeasance Deadline"):

               (i)  Borrower provides to Lender one or more Substitute
          Properties in place of the Oklahoma Property as if the Oklahoma
          Property constituted the Replaced Property for which such one or more
          Substitute Properties is being replaced and satisfies all of the
          conditions and requirements set forth in Section 2.12 of the Loan
          Agreement relating to a Substitution (including all conditions
          incorporated by reference in such Section) involving such Substitute
          Properties, subject to the following:

                    (A) for the purpose of Section 2.12(a), the Substitute
          Property or Substitute Properties must have an aggregate NOI of not
          less than $418,716.00; and

                                        5

<PAGE>

                    (B) for the purpose of Section 2.12(b), the Substitute
          Property or Substitute Properties must have an aggregate FMV of not
          less than $4,000,000.00;

          or

               (ii) Borrower pays to Lender a Defeasance Deposit sufficient to
          enable Lender to purchase the Defeasance Collateral for the Partial
          Defeasance of the Oklahoma Property and covenants to comply with all
          of the conditions and requirements set forth in Section 1.03 of the
          Note relating to a Partial Defeasance, subject to the following:

                    (A) for the purpose of Section 1.03 of the Note, the
          Defeasance Date (as defined in the Note) shall be the Payment Date
          that occurs immediately after the Oklahoma Property Substitution or
          Partial Defeasance Deadline and it shall not be necessary for Borrower
          to give to Lender prior written notice of such date;

                    (B) for the purpose of Section 1.03(a)(3) of the Note, the
          amount of the Defeased Note and the principal amount of the Loan to be
          defeased shall be $3,555,466.50.

          (c)  Borrower's failure to either provide to Lender a Substitute
     Property or Substitute Properties pursuant to Paragraph 7(b)(i) above or
     the Defeasance Deposit pursuant to Paragraph 7(b)(ii) above on or before
     the Oklahoma Property Substitution or Partial Defeasance Deadline shall
     constitute an Event of Default under the Loan Agreement.

          (d)  No Property (other than the Oklahoma Property, to the extent not
     already released) shall be released from the lien of the applicable
     Mortgage or the other Loan Documents under this Amendment.

          (e)  Borrower hereby unconditionally and irrevocably assigns, conveys,
     pledges, mortgages, transfers, delivers, deposits, sets over and confirms
     unto Lender, and hereby grants to Lender a security interest in, (i) the
     Interim Cash Reserve Deposit, (ii) the Interim Cash Reserve Deposit Account
     or any other account into which the Interim Cash Reserve Deposit will be
     deposited, (iii) all accounts, contract rights and general intangibles or
     other rights and interests pertaining thereto, (iv) all sums now or
     hereafter therein or represented thereby, (v) all replacements,
     substitutions or proceeds thereof, (vi) all instruments and documents now
     or hereafter evidencing the Interim Cash Reserve Deposit or such accounts,
     (vii) all powers, options, rights, privileges and immunities pertaining to
     the Interim Cash Reserve Deposit Account (including the right to make
     withdrawals therefrom), and (viii) all proceeds of the foregoing. Borrower
     hereby authorizes and consents to the account into which the Interim Cash
     Reserve Deposit will be deposited being held in Lender's name or the name
     of any entity servicing the Loan for Lender and hereby acknowledges and
     agrees, that Lender, or at Lender's election, such servicing agent, shall
     have exclusive control over said account. Notice of the assignment and
     security interest granted to Lender herein may be delivered by Lender at

                                        6

<PAGE>

     any time to the financial institution wherein the Interim Cash Reserve
     Deposit Account has been established, and Lender, or such servicing entity,
     shall have possession of all passbooks or other evidences of such accounts.
     Borrower hereby waives all right to withdraw funds from the Interim Cash
     Reserve Deposit Account. If an Event of Default shall occur hereunder or
     under any other of the Loan Documents, then Lender may, without notice or
     demand on Borrower, at its option: (A) withdraw any or all of the funds
     (including, without limitation, interest) then remaining in the Interim
     Cash Reserve Deposit Account and apply the same, after deducting all costs
     and expenses of safekeeping, collection and delivery (including, but not
     limited to, reasonable attorneys' fees, costs and expenses) to pay
     principal, interest and other amounts under the Loan Documents, in such
     order and manner as the Lender may elect in its sole discretion, (B)
     exercise any and all rights and remedies of a secured party under any
     applicable Uniform Commercial Code, and/or (C) exercise any other remedies
     available at law or in equity.

     8.   Effect of this Amendment. Except as specifically amended above, (a)
the Loan Agreement and the other Loan Documents shall remain in full force and
effect and are hereby ratified and affirmed and (b) the execution, delivery and
effectiveness of this Amendment shall not, except as expressly provided herein,
operate as a waiver of any right, power, or remedy of Lender, the
Certificateholders or Servicer, nor constitute a waiver of any provision of the
Loan Agreement or any other Operative Document. The amendments effected by
Paragraph 3 above shall be effective only as to this specific instance with
respect to the Oklahoma Property, and shall not be deemed to be an agreement by
Lender to amend the Loan Documents for any subsequent request by Borrower or for
any similar matter.

     9.   Miscellaneous.

          (a)  Counterparts. This Amendment may be executed in any number of
     identical counterparts, any set of which signed by all the parties hereto
     shall be deemed to constitute a complete, executed original for all
     purposes.

          (b)  Headings. Headings in this Amendment are for convenience of
     reference only and are not part of the substance hereof.

          (c)  Governing Law. This Amendment shall be governed by and construed
     in accordance with the laws of the State of New York without reference to
     conflicts of law rules.

                            [Signature page follows]

                                        7

<PAGE>

     IN WITNESS WHEREOF, Borrower, Lender, the Certificateholders and Servicer
have caused this Amendment to be executed as of the day and year first above
written.

BORROWER:                            CATELLUS FINANCE 1, L.L.C.,
                                     a Delaware limited liability company


                                     By: /s/ William Lau
                                        ----------------------------------------
                                     Name: William Lau
                                          --------------------------------------
                                     Title: Vice President, Finance & Treasurer
                                           -------------------------------------


LENDER:                              LASALLE BANK NATIONAL ASSOCIATION,
                                     f/k/a LaSalle National Bank,
                                     as trustee for the registered Holders of
                                     Prudential Mortgage Capital Company I, LLC,
                                     Commercial Mortgage Pass-Through
                                     Certificates, Series 1998-1


                                     By: /s/ Brian Ames
                                        ----------------------------------------
                                     Name: Brian Ames
                                          --------------------------------------
                                     Title: Vice President
                                           -------------------------------------


SERVICER:                            THE PRUDENTIAL INSURANCE COMPANY OF AMERICA


                                     By: /s/ Tom Moore
                                        ----------------------------------------
                                     Name: Tom Moore
                                          --------------------------------------
                                     Title: Vice President
                                           -------------------------------------


CERTIFICATEHOLDERS:                  THE PRUDENTIAL INSURANCE COMPANY OF AMERICA


                                     By: /s/ Jean Baker
                                        ----------------------------------------
                                     Name: Jean Baker
                                          --------------------------------------
                                     Title: Principal
                                           -------------------------------------

                                       8

<PAGE>

                                   SCHEDULE I

                           LIST OF CERTIFICATEHOLDERS


                   The Prudential Insurance Company of America

<PAGE>

                                    EXHIBIT A

                     LEGAL DESCRIPTION OF OKLAHOMA PROPERTY

The land referred to herein is located in the City of Oklahoma City, County of
Oklahoma, State of Oklahoma, and is described as follows:

A tract of land lying in the Southeast Quarter (SE/4) of the Southeast Quarter
(SE/4) of Section Thirty (30), Township Eleven (11) North, Range Two (2) West of
the Indian Meridian, Oklahoma City, Oklahoma County, Oklahoma and being more
particularly described as follows:

Commencing at the Southeast corner of said Section 30;

Thence North 00(degree)24'35" West along the East line of said Section 30, a
distance of 759.49 feet;

Thence South 89(degree)38'02" West a distance of 60.00 feet to a point on the
West right-of-way of Sunnylane Road, said point being the point or place of
beginning;

Thence South 89(degree)38'02" West along the North right-of-way line of the
Atchison, Topeka and Santa Fe Railway, a distance of 663.67 feet;

Thence North 00(degree)24'35" West 471.00 feet;

Thence North 89(degree)38'02" East a distance of 663.67 feet to a point on the
West right-of-way of S. Sunnylane Road;

Thence South 00(degree)24'35" East along said right-of-way a distance of 471.00
feet to the point or place of beginning.

<PAGE>

                                    EXHIBIT B

 FORM OF RELEASE OF MORTGAGE, ASSIGNMENT OF LEASES AND RENTS, SECURITY AGREEMENT
              AND FIXTURE FILING WITH RESPECT TO OKLAHOMA PROPERTY


                                 See Attachment.

<PAGE>

                                    EXHIBIT C

                                 FORM OF RELEASE
                        OF ASSIGNMENT OF LEASES AND RENTS
                        WITH RESPECT TO OKLAHOMA PROPERTY

                                 See Attachment.

<PAGE>

                                    EXHIBIT D

                                  FORM OF UCC-3
                              TERMINATION STATEMENT
                        WITH RESPECT TO OKLAHOMA PROPERTY


                                 See Attachment

<PAGE>

                                    EXHIBIT E

                              FORM OF REAFFIRMATION

                                 See Attachment.

<PAGE>

          RELEASE OF MORTGAGE, ASSIGNMENT OF LEASES AND RENTS, SECURITY
                          AGREEMENT AND FIXTURE FILING

                                 by and between

                           CATELLUS FINANCE 1, L.L.C.,
                      a Delaware limited liability company,

                                  as Mortgagor

                                       and

                       LASALLE BANK NATIONAL ASSOCIATION,
                          f/k/a LaSalle National Bank,
as trustee for the registered Holders of Prudential Mortgage Capital Company I,
       LLC, Commercial Mortgage Pass-Through Certificates, Series 1998-1,

                                  as Mortgagee

                          Dated as of December 23, 2002

--------------------------------------------------------------------------------

                        County of Oklahoma (the "County")

                         State of Oklahoma (the "State")

--------------------------------------------------------------------------------

                              Record and Return to:

                       Orrick, Herrington & Sutcliffe LLP
                               400 Sansome Street
                             San Francisco, CA 94111
                                Attn: Gary Louie

<PAGE>


              RELEASE OF MORTGAGE, ASSIGNMENT OF LEASES AND RENTS,
                      SECURITY AGREEMENT AND FIXTURE FILING

     THIS RELEASE OF MORTGAGE, ASSIGNMENT OF LEASES AND RENTS, SECURITY
AGREEMENT AND FIXTURE FILING (this "Release"), dated as of December 23, 2002, is
entered into by and between CATELLUS FINANCE 1, L.L.C., a Delaware limited
liability company ("Mortgagor"), having an address at 201 Mission Street, Suite
340, San Francisco, California 94105, and by LASALLE BANK NATIONAL ASSOCIATION,
f/k/a LaSalle National Bank, as trustee for the registered Holders of Prudential
Mortgage Capital Company I, LLC, Commercial Mortgage Pass-Through Certificates,
Series 1998-1 ("Mortgagee"), having an address at 135 South LaSalle Street,
Suite 1625, Chicago, Illinois 60647-4107.

                                    RECITALS

          A.   Reference is made to that certain loan agreement dated as of
October 26, 1998 (the "Original Loan Agreement") between Mortgagor and
PRUDENTIAL MORTGAGE CAPITAL COMPANY, INC., a Delaware corporation
("Prudential"), predecessor-in-interest to Mortgagee, as amended by that certain
First Amendment to Loan Agreement dated as of January 11, 2001, the Second
Amendment to Loan Agreement dated as of February 8, 2001 (the "Second
Amendment"), the Second [sic] Amendment to Loan Agreement dated as of August 27,
2002 (the "Third Amendment"), and the Fourth Amendment to Loan Agreement dated
as of December 23, 2002 (the "Fourth Amendment") (the Original Loan Agreement as
amended by the First Amendment, the Second Amendment, the Third Amendment, and
the Fourth Amendment, as the same may hereinafter be consolidated, extended,
modified, amended and/or restated or renewed from time to time, the "Loan
Agreement"). Pursuant to the terms of the Original Loan Agreement, Prudential
agreed to extend a loan (the "Loan"), evidenced by that certain Promissory Note
dated October 26, 1998, in the original principal amount of THREE HUNDRED
SEVENTY-THREE MILLION AND 00/100 DOLLARS ($373,000,000.00), and secured by,
among other things, that certain Mortgage, Assignment of Leases and Rents,
Security Agreement and Fixture Filing dated as of October 26, 1998, and recorded
on October 28, 1998 in the Real Estate Records of Oklahoma County in Book 7435,
Page 1430, as Instrument No. 1998156048 as assigned to Mortgagee pursuant to an
Assignment of Mortgage, Assignment of Leases and Rents and Security Agreement
dated as of November 23, 1998, and recorded on October 14, 1999 in the Real
Estate Records of Oklahoma County in Book 7705, Page 80 as Instrument No.
1999157693 (the "Oklahoma Mortgage").

          B.   Mortgagee and Mortgagor now desire to release all the property
encumbered by the Oklahoma Mortgage from the lien thereof.

                                    AGREEMENT

     NOW, THEREFORE, in consideration of the above recitals and for other good
and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, Mortgagee hereby agrees as follows:

<PAGE>

     1.   Definitions. All capitalized terms defined above and elsewhere in this
Release shall be used herein as so defined. Unless otherwise defined herein, all
other capitalized terms used herein shall have the respective meanings given to
those terms in the Loan Agreement.

     2.   Release of Property under Oklahoma Mortgage. Mortgagee hereby releases
and discharges from the lien of the Oklahoma Mortgage all of the real property
and improvements encumbered by the Oklahoma Mortgage which is more particularly
described on Exhibit A attached hereto and made a part hereof.

     3.   Effect of this Release. Notwithstanding this Release, (a) the Loan
Agreement, the Oklahoma Mortgage and the other Loan Documents shall remain in
full force and effect and are hereby ratified and affirmed and (b) the
execution, delivery and effectiveness of this Release shall not, except as
expressly provided herein, operate as a waiver of any right, power, or remedy of
Mortgagee, nor constitute a waiver of any provision of the Loan Agreement or any
other Loan Document.

     4.   Miscellaneous.

          (a)  Headings. Headings in this Release are for convenience of
     reference only and are not part of the substance hereof.

          (b)  Governing Law. This Release shall be governed by and construed in
     accordance with the laws of the State of New York and the laws of the State
     of Oklahoma as provided in the Oklahoma Mortgage.

                          [The signature page follows]

                                       -2-

<PAGE>

     IN WITNESS WHEREOF, Mortgagee has caused this Release to be executed as of
the day and year first above written.

                             MORTGAGEE:

                             LASALLE BANK NATIONAL ASSOCIATION,
                             f/k/a LaSalle National Bank,
                             as trustee for the registered Holders of Prudential
                             Mortgage Capital Company I, LLC, Commercial
                             Mortgage Pass-Through Certificates, Series 1998-1

                             By:    The Prudential Insurance Company of
                                    America, as Servicer

                                    By:
                                       -----------------------------------------
                                    Name:          J. Michael Welborn
                                    Title:           Vice President

                                       -3-

<PAGE>

                              NOTARY ACKNOWLEDGMENT

State of_______________                         *** OPTIONAL SECTION ***
County of______________                        CAPACITY CLAIMED BY SIGNER
On this_______day of ___________, 2002,
before me,                               Through statute does not require the
                                         Notary to fill in he data below, doing
______________________________________,  so may prove invaluable o persons
       Name, title of Officer            relying on the document

Personally appeared___________________,  [ ]     INDIVIDUAL
                   Name(s) of Signer(s)  [ ]     CORPORATE OFFICERS(S)
                                         [ ]     PARTNER(S)   [ ]    LIMITED
[ ] personally known to me - OR - [ ]                         [ ]    GENERAL
proved to me on the basis of             [ ]     ATTORNEY-IN-FACT
satisfactory evidence to be the          [ ]     TRUSTEE(S)
person(s) whose name(s) is/are           [ ]     GUARDIAN/CONSERVATOR
subscribed to the within instrument and  [ ]     OTHER:________________________
acknowledged to me that he/she/they
executed the same in his/her/their       SIGNER IS REPRESENTING:
authorized capacity(ies), and that by    NAME OF PERSON(S) OR ENTITY(IES)
his/her/their signature(s) on the
instrument the person(s), or the entity
upon behalf of which the person(s)       --------------------------------------
acted, executed the instrument.

WITNESS my hand and official seal.

--------------------------------------
          SIGNATURE OF NOTARY

             ****************** OPTIONAL SECTION ******************

THIS CERTIFICATE MUST BE ATTACHED TO THE DOCUMENT DESCRIBED BELOW:
TITLE OR TYPE OF DOCUMENT______________________________________________________
NUMBER OF PAGES _____________ DATE OF DOCUMENT_________________________________
SIGNER(S) OTHER THAN NAMED ABOVE_______________________________________________
Though the data requested here is not required by law, it could prevent
fraudulent reattachment of this form.

<PAGE>

                                    EXHIBIT A

The land referred to herein is located in the City of Oklahoma City, County of
Oklahoma, State of Oklahoma, and is described as follows:

A tract of land lying in the Southeast Quarter (SE/4) of the Southeast Quarter
(SE/4) of Section Thirty (30), Township Eleven (11) North, Range Two (2) West of
the Indian Meridian, Oklahoma City, Oklahoma County, Oklahoma and being more
particularly described as follows:

Commencing at the Southeast corner of said Section 30;

Thence North 00DEG.24'35" West along the East line of said Section 30, a
distance of 759.49 feet;

Thence South 89DEG.38'02" West a distance of 60.00 feet to a point on the West
right-of-way of Sunnylane Road, said point being the point or place of
beginning;

Thence South 89DEG.38'02" West along the North right-of-way line of the
Atchison, Topeka and Santa Fe Railway, a distance of 663.67 feet;

Thence North 00DEG.24'35" West 471.00 feet;

Thence North 89DEG.38'02" East a distance of 663.67 feet to a point on the West
right-of-way of S. Sunnylane Road;

Thence South 00DEG.24'35" East along said right-of-way a distance of 471.00 feet
to the point or place of beginning.

<PAGE>

                                   RELEASE OF
                         ASSIGNMENT OF LEASES AND RENTS

                                 by and between

                           CATELLUS FINANCE 1, L.L.C.,
                      a Delaware limited liability company,

                                   as Assignor

                                       and
                       LASALLE BANK NATIONAL ASSOCIATION,
                          f/k/a LaSalle National Bank,
                          as trustee for the registered
             Holders of Prudential Mortgage Capital Company I, LLC,
          Commercial Mortgage Pass-Through Certificates, Series 1998-1,

                                   as Assignee

                          Dated as of December 23, 2002

--------------------------------------------------------------------------------

                        County of Oklahoma (the "County")
                         State of Oklahoma (the "State")

--------------------------------------------------------------------------------

                              Record and Return to:

                       Orrick, Herrington & Sutcliffe LLP
                               400 Sansome Street
                             San Francisco, CA 94111
                                Attn: Gary Louie

<PAGE>

                                   RELEASE OF
                         ASSIGNMENT OF LEASES AND RENTS

     THIS RELEASE OF ASSIGNMENT OF LEASES AND RENTS (this "Release"), dated as
of December 23, 2002, is entered into by and between CATELLUS FINANCE 1, L.L.C.,
a Delaware limited liability company ("Assignor"), having an address at 201
Mission Street, Suite 340, San Francisco, California 94105, and by LASALLE BANK
NATIONAL ASSOCIATION, f/k/a LaSalle National Bank, as trustee for the registered
Holders of Prudential Mortgage Capital Company I, LLC, Commercial Mortgage
Pass-Through Certificates, Series 1998-1 ("Assignee"), having an address at 135
South LaSalle Street, Suite 1625, Chicago, Illinois 60647-4107.

                                    RECITALS

          A.   Reference is made to that certain loan agreement dated as of
October 26, 1998 (the "Original Loan Agreement") between Assignor and PRUDENTIAL
MORTGAGE CAPITAL COMPANY, INC., a Delaware corporation ("Prudential"),
predecessor-in-interest to Assignee, as amended by that certain First Amendment
to Loan Agreement dated as of January 11, 2001, (the "First Amendment"), the
Second Amendment to Loan Agreement dated as of February 8, 2001 (the "Second
Amendment"), the Second [sic] Amendment to Loan Agreement dated as of August 27,
2002 (the "Third Amendment"), and the Fourth Amendment to Loan Agreement dated
as of December 23, 2002 (the "Fourth Amendment") (the Original Loan Agreement as
amended by the First Amendment, the Second Amendment, the Third Amendment and
the Fourth Amendment, as the same may hereinafter be consolidated, extended,
modified, amended and/or restated or renewed from time to time, the "Loan
Agreement"). Pursuant to the terms of the Original Loan Agreement, Prudential
agreed to extend a loan (the "Loan"), evidenced by that certain Promissory Note
dated October 26, 1998, in the original principal amount of THREE HUNDRED
SEVENTY-THREE MILLION AND 00/100 DOLLARS ($373,000,000.00), and secured by,
among other things, that certain Assignment of Leases and Rents dated as of
October 26, 1998, and recorded on October 28, 1998 in the Real Estate Records of
Oklahoma County in Book 7435, Page 1476, as Instrument No. 1998156050 as
assigned to Assignee pursuant to an Assignment of Assignment of Leases and Rents
dated as of November 23, 1998, and recorded on October 14, 1999 in the Real
Estate Records of Oklahoma County in Book 7705, Page 84, as Instrument No.
1999157694 (the "Oklahoma Assignment of Leases").

          B.   Assignee and Assignor now desire to release all the property
encumbered by the Oklahoma Assignment of Leases from the lien thereof.

                                    AGREEMENT

     NOW, THEREFORE, in consideration of the above recitals and for other good
and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, Assignee hereby agrees as follows:

<PAGE>

     1.   Definitions. All capitalized terms defined above and elsewhere in this
Release shall be used herein as so defined. Unless otherwise defined herein, all
other capitalized terms used herein shall have the respective meanings given to
those terms in the Loan Agreement.

     2.   Release of Property under Oklahoma Assignment of Leases. Assignee
hereby releases and discharges from the lien of the Oklahoma Assignment of
Leases all of the real property and improvements encumbered by the Oklahoma
Assignment of Leases which is more particularly described on Exhibit A attached
hereto and made a part hereof.

     3.   Effect of this Release. Notwithstanding this Release, (a) the Loan
Agreement and the other Loan Documents shall remain in full force and effect and
are hereby ratified and affirmed and (b) the execution, delivery and
effectiveness of this Release shall not, except as expressly provided herein,
operate as a waiver of any right, power, or remedy of Assignee, nor constitute a
waiver of any provision of the Loan Agreement or any other Loan Document.

     4.   Miscellaneous.

          (a)  Headings. Headings in this Release are for convenience of
     reference only and are not part of the substance hereof.

          (b)  Governing Law. This Release shall be governed by and construed in
     accordance with the laws of the State of New York and the laws of the State
     of Oklahoma as provided in the Oklahoma Assignment of Leases.

                          [The signature page follows.]

                                       -2-

<PAGE>

     IN WITNESS WHEREOF, Assignee has caused this Release to be executed as of
the day and year first above written.

                             ASSIGNEE:

                             LASALLE BANK NATIONAL ASSOCIATION,
                             f/k/a LaSalle National Bank,
                             as trustee for the registered Holders of Prudential
                             Mortgage Capital Company I, LLC, Commercial
                             Mortgage Pass-Through Certificates, Series 1998-1

                             By: The Prudential Insurance Company of
                                 America, as Servicer

                                 By:
                                    -------------------------------------------
                                 Name:           J. Michael Welborn
                                 Title:            Vice President

                                       -3-

<PAGE>

                              NOTARY ACKNOWLEDGMENT

State of______________                          *** OPTIONAL SECTION ***
County of_____________                         CAPACITY CLAIMED BY SIGNER
On this______ day of ___________, 2002,
before me,                               Through statute does not require the
______________________________________,  Notary to fill in he data below, doing
        Name, title of Officer           so may prove invaluable o persons
                                         relying on the document
Personally appeared __________________,
                    Name(s) of Signer(s) [ ]     INDIVIDUAL
                                         [ ]     CORPORATE OFFICERS(S)
[ ] personally known to me - OR - [ ]    [ ]     PARTNER(S) [ ]     LIMITED
proved to me on the basis of                                [ ]     GENERAL
satisfactory evidence to be the          [ ]     ATTORNEY-IN-FACT
person(s) whose name(s) is/are           [ ]     TRUSTEE(S)
subscribed to the within instrument and  [ ]     GUARDIAN/CONSERVATOR
acknowledged to me that he/she/they      [ ]     OTHER:________________________
executed the same in his/her/their
authorized capacity(ies), and that by
his/her/their signature(s) on the
instrument the person(s), or the entity  SIGNER IS REPRESENTING:
upon behalf of which the person(s)       NAME OF PERSON(S) OR ENTITY(IES)
acted, executed the instrument.
                                        ---------------------------------------
WITNESS my hand and official seal.

---------------------------------------
          SIGNATURE OF NOTARY

             ****************** OPTIONAL SECTION ******************

THIS CERTIFICATE MUST BE ATTACHED TO THE DOCUMENT DESCRIBED BELOW:
TITLE OR TYPE OF DOCUMENT______________________________________________________
NUMBER OF PAGES _____________DATE OF DOCUMENT__________________________________
SIGNER(S) OTHER THAN NAMED ABOVE_______________________________________________
Though the data requested here is not required by law, it could prevent
fraudulent reattachment of this form.

<PAGE>

                                    EXHIBIT A

The land referred to herein is located in the City of Oklahoma City, County of
Oklahoma, State of Oklahoma, and is described as follows:

A tract of land lying in the Southeast Quarter (SE/4) of the Southeast Quarter
(SE/4) of Section Thirty (30), Township Eleven (11) North, Range Two (2) West of
the Indian Meridian, Oklahoma City, Oklahoma County, Oklahoma and being more
particularly described as follows:

Commencing at the Southeast corner of said Section 30;

Thence North 00DEG.24'35" West along the East line of said Section 30, a
distance of 759.49 feet;

Thence South 89DEG.38'02" West a distance of 60.00 feet to a point on the West
right-of-way of Sunnylane Road, said point being the point or place of
beginning;

Thence South 89DEG.38'02" West along the North right-of-way line of the
Atchison, Topeka and Santa Fe Railway, a distance of 663.67 feet;

Thence North 00DEG.24'35" West 471.00 feet;

Thence North 89DEG.38'02" East a distance of 663.67 feet to a point on the West
right-of-way of S. Sunnylane Road;

Thence South 00DEG.24'35" East along said right-of-way a distance of 471.00 feet
to the point or place of beginning.

<PAGE>

[GRAPHIC APPEARS HERE]

UCC FINANCING STATEMENT AMENDMENT
FOLLOW INSTRUCTIONS (front and back) CAREFULLY
-----------------------------------------------
A. NAME & PHONE OF CONTACT AT FILER [optional]

-----------------------------------------------
B. SEND ACKNOWLEDGMENT TO: (Name and Address)

      Orrick, Herrington & Sutcliffe LLP                DOC # T2003000250214
      400 Sansome Street
      San Francisco, CA 94111                           [SEAL]
      Attn: Gary Louie
-----------------------------------------------
<TABLE>
<S>                                            <C>
                                               THE ABOVE SPACE IS FOR FILING OFFICE USE ONLY
---------------------------------------------------------------------------------------------------------------------------
1a. INITIAL FINANCING STATEMENT FILE #            1b. This FINANCING STATEMENT AMENDMENT is to be filed [for record]
N0008998                                          [X] (or recorded) in the REAL ESTATE RECORDS.
---------------------------------------------------------------------------------------------------------------------------
2. [X] TERMINATION: Effectiveness of the Financing Statement identified above is terminated with respect to security
       interest(s) of the Secured Party authorizing this Termination Statement.
---------------------------------------------------------------------------------------------------------------------------
3. [_] CONTINUATION: Effectiveness of the Financing Statement identified above with respect to security interest(s) of the
       Secured Party authorizing this Continuation Statement is continued for the additional period provided by applicable
       law.
---------------------------------------------------------------------------------------------------------------------------
4. [_] ASSIGNMENT (full or partial): Give name of assignee in item 7a or 7b and address of assignee in item 7c; and also
       give name of assignor in item 9.
---------------------------------------------------------------------------------------------------------------------------
5.     AMENDMENT (PARTY INFORMATION): This Amendment affects [_] Debtor or [_] Secured Party of record. Check only one of
                                                                        --                                         ---
       these two boxes.

       Also check one of the following three boxes and provide appropriate information in items 6 and/or 7.
                  ---                              ---
   [_] CHANGE name and/or address: Give   [_] DELETE name: Give record name to  [_] ADD name: Complete item 7a or 7b, and
       current record name in item 6a or      be deleted in item 6a or 6b.          also item 7c; also complete items
       6b; also give new name (if name                                              7d-7g (if applicable).
       change) in item 7a or 7b and/or
       new address (if address change)
       in item 7c.
---------------------------------------------------------------------------------------------------------------------------
6. CURRENT RECORD INFORMATION:
   ------------------------------------------------------------------------------------------------------------------------
   6a. ORGANIZATION'S NAME
                          Catellus Finance 1, L.L.C.

OR ------------------------------------------------------------------------------------------------------------------------
   6b. INDIVIDUAL'S LAST NAME           FIRST NAME                 MIDDLE NAME                SUFFIX

---------------------------------------------------------------------------------------------------------------------------
7. CHANGED (NEW) OR ADDED INFORMATION:
---------------------------------------------------------------------------------------------------------------------------
   7a. ORGANIZATION'S NAME

OR ------------------------------------------------------------------------------------------------------------------------
   7b. INDIVIDUAL'S LAST NAME           FIRST NAME                 MIDDLE NAME                SUFFIX

---------------------------------------------------------------------------------------------------------------------------
7c. MAILING ADDRESS                     CITY                       STATE    POSTAL CODE       COUNTRY

---------------------------------------------------------------------------------------------------------------------------
7d. TAX ID #: SSN OR EIN  ADD'L INFO RE 7e. TYPE OF ORGANIZATION   7f. JURISDICTION OF   7g. ORGANIZATIONAL ID #,
                          ORGANIZATION                                  ORGANIZATION          if any
                          DEBTOR                                                                                   [_] NONE
---------------------------------------------------------------------------------------------------------------------------

8. AMENDMENT (COLLATERAL CHANGE): check only one box.

   Describe collateral [_] deleted or [_] added, or give entire [_] restated collateral description, or describe collateral
   [_] assigned.

---------------------------------------------------------------------------------------------------------------------------
9. NAME OF SECURED PARTY OF RECORD AUTHORIZING THIS AMENDMENT (name of assignor, if this is an Assignment). If this is an
   Amendment authorized by a Debtor which adds collateral or adds the authorizing Debtor, or if this is a Termination
   authorized by a Debtor, check here [_] and enter name of DEBTOR authorizing this Amendment.
    ------------------------------------------------------------------------------------------------------------------------
   9a. ORGANIZATION'S NAME  LASALLE BANK NATIONAL ASSOCIATION, as Trustee for the registered Holders of Prudential Mortgage
       Capital Company 1, LLC, Commercial Mortgage Pass-Through Certificates, Series 1998-1
OR ------------------------------------------------------------------------------------------------------------------------

---------------------------------------------------------------------------------------------------------------------------
10. OPTIONAL FILER REFERENCE DATA

---------------------------------------------------------------------------------------------------------------------------
</TABLE>

FILING OFFICE COPY - NATIONAL UCC FINANCING STATEMENT AMENDMENT (FORM UCC3)(REV.
07/29/98)

<PAGE>

                  AGREEMENT OF CATELLUS DEVELOPMENT CORPORATION
                               AND PLATO REIT, LLC

          This AGREEMENT OF CATELLUS DEVELOPMENT CORPORATION AND PLATO REIT, LLC
(this "Agreement") is made as of December 23, 2002, by and among CATELLUS
DEVELOPMENT CORPORATION, a Delaware corporation ("Catellus"), PLATO REIT, LLC, a
Delaware limited liability company ("Plato"), and LASALLE BANK NATIONAL
ASSOCIATION, f/k/a LaSalle National Bank, as trustee for the registered Holders
of Prudential Mortgage Capital Company I, LLC, Commercial Mortgage Pass-Through
Certificates, Series 1998-1, having an address at 135 South LaSalle Street,
Suite 1625, Chicago, Illinois 60674-4107 (the "Lender").

                                    RECITALS

          WHEREAS, CATELLUS FINANCE 1, L.L.C., a Delaware limited liability
company ("Borrower"), previously obtained a loan in the principal amount of
THREE HUNDRED SEVENTY-THREE MILLION and 00/100 Dollars ($373,000,000.00) (the
"Loan") in accordance with the terms and conditions of that certain loan
agreement dated as of October 26, 1998, between Borrower and PRUDENTIAL MORTGAGE
CAPITAL COMPANY, INC., a Delaware corporation ("Prudential"),
predecessor-in-interest to Lender under the Loan (the "Original Loan
Agreement"), as amended by that certain First Amendment to Loan Agreement, dated
as of January 11, 2001 (the "First Amendment"), that certain Second Amendment to
Loan Agreement, dated as of February 8, 2001 (the "Second Amendment") and that
certain Second [sic] Amendment to Loan Agreement, dated as of August 27, 2002
(the "Third Amendment") (the Original Loan Agreement as amended by the First
Amendment, the Second Amendment and the Third Amendment as the same may
hereinafter be consolidated, extended, modified, amended and/or restated or
renewed from time to time, collectively, the "Loan Agreement"; capitalized terms
used and not otherwise defined herein shall have the meanings given in the Loan
Agreement); and

          WHEREAS, Catellus, as original sole member of Borrower, transferred
its membership interest in Borrower, consisting of one-hundred percent (100%) of
the limited liability company interests in Borrower, to Plato pursuant to that
certain Assignment and Assumption of Limited Liability Company Interest dated as
of July 1, 1999, between Catellus and Plato; and

          WHEREAS, Catellus executed that certain Indemnity and Guaranty
Agreement dated as of October 26, 1998 (as subsequently amended from time to
time, the "Catellus Guaranty") and that certain Hazardous Substances Indemnity
Agreement dated as of October 26, 1998 (as subsequently amended from time to
time, the "Catellus Environmental Indemnity"), and Plato executed that certain
Indemnity and Guaranty Agreement dated as of July 1, 1999 (as subsequently
amended from time to time, the "Plato Guaranty") and that certain Hazardous
Substances Indemnity Agreement dated as of July 1, 1999 (as subsequently amended
from time to time, the "Plato Environmental Indemnity"), pursuant to which
Catellus and Plato each agreed to guarantee payment and performance to Lender of
certain obligations of Borrower under the Loan; and

          WHEREAS, Borrower has requested Lender, the Certificateholders and the
Servicer to enter into a Fourth  Amendment to the Loan Agreement dated even date
herewith (the "Fourth

<PAGE>

Amendment") which would permit Borrower to substitute a property in place of the
Oklahoma Property (as defined in the Fourth Amendment) on terms other than those
contained in the Loan Agreement and in connection therewith to release the
Oklahoma Property from the lien of the Loan Documents, including the applicable
mortgage, assignment of leases and rents and UCC-1 financing statements; and

          WHEREAS, as a condition to entering into the Fourth Amendment, Lender
has required that Catellus and Plato consent to the Fourth Amendment and
reaffirm each of their obligations under their respective guaranties.

          NOW, THEREFORE, to induce Lender to enter into the Fourth Amendment
and in consideration of the foregoing premises and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged,
Catellus and Plato each hereby represents, warrants, covenants and agrees for
the benefit of Lender as follows:

                                    AGREEMENT

          1.   Reaffirmation of Catellus Guaranty and Environmental Indemnity.
Catellus hereby consents to the Fourth Amendment, reaffirms its obligations
under the Catellus Guaranty and the Catellus Environmental Indemnity
(collectively, the "Catellus Guaranties"), and reaffirms its waiver of each and
every one of the defenses to such obligations as set forth in the Catellus
Guaranties. Catellus specifically, but not by way of limitation, hereby further
reaffirms that its obligations under the Catellus Guaranties are separate and
distinct from Borrower's obligations under the Loan Agreement and the other Loan
Documents and from Plato's obligations under the Plato Guaranty and the Plato
Environmental Indemnity in favor of Lender.

          2.   Reaffirmation of Plato Guaranty and Environmental Indemnity.
Plato hereby consents to the Fourth Amendment, reaffirms its obligations under
the Plato Guaranty and the Plato Environmental Indemnity (collectively, the
"Plato Guaranties"), and reaffirms its waiver of each and every one of the
defenses to such obligations as set forth in the Plato Guaranties. Plato
specifically, but not by way of limitation, hereby further reaffirms that its
obligations under the Plato Guaranties are separate and distinct from Borrower's
obligations under the Loan Agreement and the other Loan Documents and from
Catellus' obligations under the Catellus Guaranties in favor of Lender.

          3.   Governing Law. This Agreement shall be governed by and construed
in accordance with the laws of the State of New York without reference to
conflicts of laws rules.

          4.   Counterparts. This Agreement may be executed in any number of
counterparts, each of which when executed and delivered shall be deemed to be an
original, and all such counterparts together shall constitute one and the same
instrument.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

                                        2

<PAGE>

          IN WITNESS WHEREOF, the undersigned have executed this Agreement of
Catellus Development Corporation and Plato REIT, LLC, as of the day and year
first above written.


                               CATELLUS DEVELOPMENT CORPORATION,
                               a Delaware corporation

                               By:
                                     -------------------------------------------

                               Name:
                                     -------------------------------------------

                               Title:
                                     -------------------------------------------

                               PLATO REIT, LLC,
                               a Delaware limited liability company

                               By:
                                     -------------------------------------------

                               Name:
                                     -------------------------------------------

                               Title:
                                     -------------------------------------------

                               LASALLE BANK NATIONAL ASSOCIATION,
                               f/k/a LaSalle National Bank, as trustee for the
                               registered Holders of Prudential Mortgage Capital
                               Company I, LLC, Commercial Mortgage Pass-
                               Through Certificates, Series 1998-1

                               By:   The Prudential Insurance Company of
                                     America, as Servicer

                                     By:
                                           -------------------------------------

                                     Name:
                                           -------------------------------------

                                     Title:
                                           -------------------------------------

                                        3