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                                                                    EXHIBIT 99.1

                                November 1, 2000



Developers Diversified Realty Corporation
34555 Chagrin Boulevard
Moreland Hills, Ohio

         Re:      Voting Agreement

Ladies and Gentlemen:

                  The undersigned understands that Developers Diversified Realty
Corporation, an Ohio corporation ("DDRC"), DDR Transitory Sub Inc., a Texas
corporation ("DDR Sub"), and American Industrial Properties REIT, a Texas real
estate investment trust ("AIP"), are entering into an Agreement and Plan of
Merger to be dated on or about the date hereof (the "Agreement"), providing for,
among other things, the merger of DDR Sub into AIP (the "Merger"). Consummation
of the Merger will require the approval of the shareholders of AIP.

                  The undersigned is a shareholder of AIP (the "Shareholder")
and is entering into this letter agreement at your request, in exchange for good
and valuable consideration, the receipt and sufficiency of which is hereby
acknowledged, to induce you to enter into the Agreement and to consummate the
transactions contemplated thereby.

                  The Shareholder confirms its agreement with you as follows:

                  1. The Shareholder represents and warrants that Schedule I
annexed hereto sets forth the shares of beneficial interest of AIP of which the
Shareholder or any affiliate (as defined under the Securities Exchange Act of
1934, as amended) of the Shareholder controlled by the Shareholder (a
"Controlled Affiliate") is the beneficial owner or that the Shareholder or any
Controlled Affiliate has the power to vote or to make recommendations regarding
voting (those shares collectively, the "Shares"), and that the Shareholder and
the Controlled Affiliates, or the clients on whose behalf the Shareholder or any
Controlled Affiliate acts as a fiduciary, are, to the best of the Shareholder's
knowledge, on the date hereof the lawful owners of the number of Shares set
forth in Schedule I, free and clear of all liens, charges, encumbrances, voting
agreements and commitments of any kind, except as disclosed in Schedule I.
Except for the Shares set forth in Schedule I, neither the Shareholder nor any
Controlled Affiliate owns or holds any rights to acquire any additional shares
of beneficial interest of AIP (other than pursuant to options or conversion
rights with regard to any of the Shares, in each case as disclosed in Schedule
I) or any interest in or any voting rights with respect to any such additional
shares.

                  2. Until the earliest date referred to in Section 13, the
Shareholder agrees that it will not, and will not permit any Controlled
Affiliate to, contract to sell, sell or otherwise transfer or dispose of any of
the Shares or any interest therein or securities convertible into shares of
beneficial interest of AIP, or any voting rights with respect thereto, without
your prior written consent, in each case except to the extent that the
Shareholder determines in its good faith judgment, after consultation with its
legal counsel, that it or its Controlled Affiliate is obligated to do so in the
exercise of its fiduciary obligations.


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                  3. The Shareholder agrees that, during the term of this letter
agreement, neither it nor any Controlled Affiliate will take any action that AIP
would be prohibited from taking under Section 4.1 of the Agreement.

                  4. The Shareholder agrees that during the term of this letter
agreement (a) all of the shares of beneficial interest of AIP beneficially owned
by the Shareholder or any Controlled Affiliate, or over which the Shareholder or
any Controlled Affiliate has voting power or control, directly or indirectly,
including any such shares acquired after the date hereof, at the record date for
any meeting of shareholders of AIP called to consider and vote on the Merger and
the Agreement and the transactions contemplated thereby or any Acquisition
Proposal (as such term is defined in the Agreement), will be voted by the
Shareholder or such Controlled Affiliates, or any representative or proxy
thereof, or that the Shareholder and Controlled Affiliates will recommend that
such shares be voted, as applicable, in favor of the approval of the Merger and
the Agreement and the transactions contemplated thereby and (b) neither the
Shareholder nor any Controlled Affiliate, nor any such representative or proxy,
will vote any such shares or recommend that such shares be voted, in favor of
any Acquisition Proposal, in each case except to the extent that the Shareholder
determines in its good faith judgment, after consultation with its legal
counsel, that it is prudent so to vote or recommend otherwise in the exercise of
its fiduciary obligations.

                  5. The Shareholder agrees that the shares referred to in
Section 4 above, owned at the record date for any meeting of shareholders of AIP
called to consider and vote on the election of members of the Board of Trust
Managers of AIP (the "Board"), will be voted by the Shareholder or any
Controlled Affiliate, or any representative or proxy thereof, or that the
Shareholder will recommend that such Shares be voted, as applicable, in favor of
the approval of the election of the representatives of DDRC to the Board for so
long as DDRC has the right to nominate members of the Board under the Share
Purchase Agreement dated July 30, 1998 between DDRC and AIP, in each case except
to the extent that the Shareholder determines in its good faith judgment, after
consultation with its legal counsel, that it is prudent to vote or recommend
otherwise in the exercise of its fiduciary obligations. This Section 5 will
survive the termination of this letter agreement until the earlier of (i) the
Closing Date (as defined in the Agreement) and (ii) the day on which the
nomination right referred to above first ceases to exist.

                  6. The Shareholder hereby appoints Marc A. Simpson to attend
the special meeting of the shareholders of AIP held to consider and vote on the
Merger and to vote the shares referred to in Section 4 above, with all the power
the Shareholder would possess if personally present, in favor of the approval of
the Merger, the Agreement and the transactions contemplated thereby. The
Shareholder agrees to execute, and to cause each Controlled Affiliate to
execute, such proxies and other instruments, and to take and to cause each
Controlled Affiliate to take, such actions as may be necessary to cause all of
those shares to be so voted.

                  7. The Shareholder hereby waives and releases and agrees not
to pursue, and will cause each Controlled Affiliate to waive and release and
agree not to pursue, any claim that the Shareholder or that Controlled Affiliate
now or hereafter has or may have against AIP or DDRC or any affiliate of AIP or
of DDRC (in each case for itself and, to the extent that it has legal authority
to do so, for any beneficial or record owner of Shares for whom the Shareholder
or any Controlled Affiliate acts in an agency or fiduciary capacity), (i)
arising out of or with respect to or in connection with the Merger or the
Agreement (including but not limited to any claim asserting dissenters' rights),
or any action taken or omitted to be taken by AIP, DDRC or any such affiliate
pursuant to or in connection with the Merger or the Agreement and not in
violation of the Agreement, or (ii) otherwise arising with respect to or in
connection with the Shareholder's or Controlled Affiliate's (as applicable)
interest in or rights with respect to shares of beneficial interest of AIP, or
AIP's or DDRC's or any of their respective affiliates' actions in connection
therewith on or prior to the date hereof. The Shareholder will, and will cause
the Controlled Affiliates to, recommend to each client on whose behalf the
Shareholder or any such


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Controlled Affiliate acts as a fiduciary, and that it is advising with respect
to the Merger and the Agreement, that it not pursue any claim referred to in the
first sentence of this paragraph. The Shareholder further agrees that it will
not accept or retain, and will not permit any Controlled Affiliate to accept or
retain (in each case for itself and, to the extent that it has legal authority
to so agree, for any beneficial or record owner of Shares for whom the
Shareholder or any Controlled Affiliate acts in an agency or fiduciary
capacity), any payment, award or other benefit of any kind arising out of or
with respect to or in connection with any claim or action initiated or asserted
by any shareholder or class or other group of shareholders of AIP (i) arising
out of or with respect to or in connection with the Merger or the Agreement
(including but not limited to any claim asserting dissenters' rights), or any
action taken or omitted to be taken by AIP, DDRC or any such affiliate pursuant
to or in connection with the Merger or the Agreement and not in violation of the
Agreement, or (ii) otherwise arising out of or with respect to or in connection
with that shareholder's or class's or group's (as applicable) status as a
shareholder (or shareholders, as applicable) of AIP, or AIP's or DDRC's or any
of their respective affiliates' actions in connection therewith on or prior to
the date hereof. The Shareholder's and each Controlled Affiliate's agreements
and obligations under this Section 7 with respect to Shares attributable to
beneficial or record owners for whom the Shareholder or any Controlled Affiliate
acts in an agency or fiduciary capacity are subject to such exceptions as may be
required to enable the Shareholder and that Controlled Affiliate to comply with
their respective fiduciary duties.

                  Each of AIP and DDRC hereby waives and releases and agrees not
to pursue, and will cause each of its affiliates that it controls to waive and
release and agree not to pursue, any claim that it or that affiliate now or
hereafter has or may have with respect to or in connection with the
Shareholder's or any Controlled Affiliate's interest in or rights with respect
to shares of beneficial interest of AIP on or prior to the date hereof.
Notwithstanding anything to the contrary in this Section 7, the waiver, release
and agreement with respect to matters referred to in clause (ii) of the first
and third sentences of the first paragraph of this Section 7, and the waiver,
release and agreement set forth in the first sentence of this paragraph, will
not be effective unless and until the Merger is consummated in accordance with
the Agreement, and will automatically become effective at the time of that
consummation.

                  This Section 7 will survive the termination of this letter
agreement until the latest date permissible under applicable law.

                  8. The Shareholder has all necessary power and authority to
enter into this letter agreement. This letter agreement is the legal, valid and
binding agreement of the Shareholder, and is enforceable against the Shareholder
in accordance with its terms, subject to applicable bankruptcy, insolvency,
fraudulent conveyance, reorganization, moratorium and similar laws affecting
creditors' rights and remedies generally and to general principles of equity.
This letter agreement shall inure to the benefit of the parties hereto and the
successors and assigns of DDRC.

                  9. The Shareholder agrees that damages are an inadequate
remedy for the breach by Shareholder of any term or condition of this letter
agreement and that you shall be entitled to a temporary restraining order and
preliminary and permanent injunctive relief in order to enforce our agreements
herein.

                  10. Except to the extent that the laws of the jurisdiction of
organization of any party hereto, or any other jurisdiction, are mandatorily
applicable to matters arising under or in connection with this letter agreement,
this letter agreement shall be governed by the laws of the State of Ohio. All
actions and proceedings arising out of or relating to this letter agreement
shall be heard and determined in any United States District Court sitting in the
Northern District of Ohio.


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                  11. Each of the parties hereto irrevocably submits to the
exclusive jurisdiction of any United States District Court located in the
Northern District of Ohio, for the purpose of any action or proceeding arising
out of or relating to this letter agreement and each of the parties hereto
irrevocably agrees that all claims in respect of such action or proceeding may
be heard and determined exclusively in any federal court sitting in the Northern
District of Ohio. Each of the parties hereto agrees that a final judgment in any
action or proceeding shall be conclusive and may be enforced in other
jurisdictions by suit on the judgment or in any other manner provided by law.

                  Shareholder hereby irrevocably appoints A.G.C. Co., 1900 East
9th Street, Suite 3200, Cleveland, Ohio, as its lawful agent in and for the
State of Ohio, for and in its behalf, to accept and acknowledge service of, and
upon whom may be served, all necessary processes in any action, suit, or
proceeding arising under this Agreement that may be had or brought against it in
any federal court in the Northern District of Ohio, such service of process or
notice, or the acceptance thereof by said agent endorsed thereon, to have the
same force and effect as if served upon such corporation or individual. Nothing
in this Section 11 shall affect the right of any party hereto to serve legal
process in any other manner permitted by law. Shareholder hereby waives all
defenses of improper venue and forum non conveniens with respect to any action,
suit, or proceeding brought in the any United States District Court located in
the Northern District of Ohio and arising under this letter agreement.

                  12. This letter agreement constitutes the entire agreement
between the parties hereto with respect to the matters covered hereby and
supersedes all prior agreements, understandings or representations between the
parties, written or oral, with respect to the subject matter hereof.

                  13. This letter agreement and the proxy granted pursuant to
Section 6 hereof shall become effective upon the execution and delivery of the
Agreement by the parties thereto. Except as otherwise provided herein, this
letter agreement and the proxy granted pursuant to Section 6 hereof shall
terminate automatically, without the need for any notice or other action by
either party, upon the earliest of (i) the date on which the Agreement is
terminated, (ii) the Closing Date, as defined in the Agreement, and (iii) May
31, 2001.

                  14. Each of the parties hereto intends that AIP be a third
party beneficiary of the provisions of this letter agreement of which it is not
a signatory, and is entitled to the benefits thereof and has the ability to
exercise the rights granted to DDRC herein as fully as if it were a full
signatory of this letter agreement.

                  15. Notwithstanding anything to the contrary contained herein,
neither AIP nor any representative of the Shareholder serving on the Board of
Trust Managers of AIP constitutes a Controlled Affiliate.

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                  Please confirm that the foregoing correctly states the
understanding between us by signing and returning to us a counterpart hereof.


                                    LaSalle Investment Management, Inc.


                                    By:  /s/ Stanley J. Kraska, Jr.
                                       -----------------------------------------
                                    Name:  Stanley J. Kraska, Jr.
                                    Title: Managing Director

                                    LaSalle Investment Management (Securities),
                                    L.P.


                                    By: /s/ Stanley J. Kraska, Jr.
                                       -----------------------------------------
                                    Name:  Stanley J. Kraska, Jr.
                                    Title: Managing Director


Confirmed on the date
first above written

Developers Diversified Realty Corporation


By: /s/ James A. Schoff
   --------------------
Name:   James A. Schoff
Title:  Vice Chairman & Chief Investment Officer

Joining as a party with respect to Section 7 only:

American Industrial Properties REIT


By: /s/ Lewis D. Friedland
   -----------------------
Name:  Lewis D. Friedland
Title: Executive V.P.



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                                   Schedule I

                   Ownership of Shares of Beneficial Interest


Owned Beneficially (including Options to Purchase Shares)



                                                         Total Number of Shares
                                                           Beneficially Owned
                                                         ----------------------
                                                      
LaSalle Investment Management, Inc.                             543,352
LaSalle Investment Management (Securities), L.P.                962,724




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