<PAGE>
                                                                     Exhibit 4.3


NUMBER                                                                    SHARES

                            AMB PROPERTY CORPORATION


              INCORPORATED UNDER THE LAWS OF THE STATE OF MARYLAND

THIS CERTIFICATE IS  TRANSFERABLE IN            SEE REVERSE FOR IMPORTANT NOTICE
BOSTON, MA OR NEW YORK, NY                          ON TRANSFER RESTRICTIONS
                                                      AND OTHER INFORMATION

                                                        CUSIP 00163T 40 6

THIS CERTIFIES THAT

                                  **Specimen**

IS THE OWNER OF

     FULLY PAID AND NONASSESSABLE SHARES OF THE 6-3/4% SERIES M CUMULATIVE
           REDEEMABLE PREFERRED STOCK, PAR VALUE $0.01 PER SHARE, OF

                            AMB PROPERTY CORPORATION

(the "Corporation") transferable on the books of the Corporation by the holder
hereof in person or by its duly authorized attorney, upon surrender of this
Certificate properly endorsed. This Certificate and the shares represented
hereby are issued and shall be paid subject to all of the provisions of the
charter of the Corporation (the "Charter") and the Bylaws of the Corporation and
any amendments thereto. This Certificate is not valid unless countersigned and
registered by the Transfer Agent and Registrar.

      IN WITNESS WHEREOF, the Corporation has caused this Certificate to be
executed on its behalf by its duly authorized officers.

DATED
      ------------------

Countersigned and Registered: EquiServe, Inc.
                              Transfer Agent
                              and Registrar         ----------------------(SEAL)
                                                    President


By:
   ---------------------                            ----------------------------
   Authorized Signature                             Secretary



<PAGE>

                                                                     Exhibit 4.3

                            AMB PROPERTY CORPORATION

                                CLASSES OF STOCK

      THE CORPORATION IS AUTHORIZED TO ISSUE CAPITAL STOCK OF MORE THAN ONE
CLASS, CONSISTING OF COMMON STOCK AND ONE OR MORE CLASSES OF PREFERRED STOCK.
THE BOARD OF DIRECTORS IS AUTHORIZED TO DETERMINE THE PREFERENCES, LIMITATIONS
AND RELATIVE RIGHTS OF ANY CLASS OF PREFERRED STOCK BEFORE THE ISSUANCE OF
SHARES OF SUCH CLASS OF PREFERRED STOCK. THE CORPORATION WILL FURNISH, WITHOUT
CHARGE, TO ANY STOCKHOLDER MAKING A WRITTEN REQUEST THEREFOR, A COPY OF THE
CORPORATION'S CHARTER AND A WRITTEN STATEMENT OF THE DESIGNATIONS, RELATIVE
RIGHTS, PREFERENCES, CONVERSION OR OTHER RIGHTS, VOTING POWERS, RESTRICTIONS,
LIMITATIONS AS TO DIVIDENDS AND OTHER DISTRIBUTIONS, QUALIFICATIONS AND TERMS
AND CONDITIONS OF REDEMPTION OF THE STOCK OF EACH CLASS WHICH THE CORPORATION
HAS THE AUTHORITY TO ISSUE AND, IF THE CORPORATION IS AUTHORIZED TO ISSUE ANY
PREFERRED OR SPECIAL CLASS IN SERIES, (i) THE DIFFERENCES IN THE RELATIVE RIGHTS
AND PREFERENCES BETWEEN THE SHARES OF EACH SERIES TO THE EXTENT SET, AND (ii)
THE AUTHORITY OF THE BOARD OF DIRECTORS TO SET SUCH RIGHTS AND PREFERENCES OF
SUBSEQUENT SERIES. REQUESTS FOR SUCH WRITTEN STATEMENT MAY BE DIRECTED TO THE
SECRETARY OF THE CORPORATION AT ITS PRINCIPAL OFFICE.

                     RESTRICTIONS ON OWNERSHIP AND TRANSFER

     IF THIS CERTIFICATE REPRESENTS SHARES OF PREFERRED STOCK, THE FOLLOWING
                            RESTRICTIONS SHALL APPLY:

      THE SHARES OF SERIES M PREFERRED STOCK REPRESENTED BY THIS CERTIFICATE ARE
SUBJECT TO RESTRICTIONS ON BENEFICIAL AND CONSTRUCTIVE OWNERSHIP AND TRANSFER
FOR THE PURPOSE OF THE CORPORATION'S MAINTENANCE OF ITS STATUS AS A REAL ESTATE
INVESTMENT TRUST UNDER THE INTERNAL REVENUE CODE OF 1986, AS AMENDED (THE
"CODE"). SUBJECT TO CERTAIN FURTHER RESTRICTIONS AND EXCEPT AS EXPRESSLY
PROVIDED IN THE ARTICLES SUPPLEMENTARY FOR THE SERIES M PREFERRED STOCK (I) NO
PERSON MAY BENEFICIALLY OWN SHARES OF THE CORPORATION'S SERIES M PREFERRED STOCK
IN EXCESS OF 9.8% (BY VALUE OR BY NUMBER OF SHARES, WHICHEVER IS MORE
RESTRICTIVE) OF THE OUTSTANDING SERIES M PREFERRED STOCK OF THE CORPORATION;
(II) NO PERSON MAY CONSTRUCTIVELY OWN SHARES OF THE CORPORATION'S SERIES M
PREFERRED STOCK IN EXCESS OF 9.8% (BY VALUE OR BY NUMBER OF SHARES, WHICHEVER IS
MORE RESTRICTIVE) OF THE OUTSTANDING SERIES M PREFERRED STOCK OF THE
CORPORATION; (III) NO PERSON MAY BENEFICIALLY OR CONSTRUCTIVELY OWN SHARES OF
THE CORPORATION'S SERIES M PREFERRED STOCK THAT, TAKING INTO ACCOUNT ANY OTHER
CAPITAL STOCK OF THE CORPORATION BENEFICIALLY OR CONSTRUCTIVELY OWNED BY SUCH
PERSON, WOULD RESULT IN THE CORPORATION BEING "CLOSELY HELD" UNDER SECTION
856(h) OF THE CODE OR OTHERWISE CAUSE THE CORPORATION TO FAIL TO QUALIFY AS A
REIT; AND (IV) NO PERSON MAY TRANSFER SHARES OF SERIES M PREFERRED STOCK IF SUCH
TRANSFER WOULD RESULT IN THE CAPITAL STOCK OF THE CORPORATION BEING OWNED BY
FEWER THAN 100 PERSONS. ANY PERSON WHO BENEFICIALLY OR CONSTRUCTIVELY OWNS OR
ATTEMPTS TO BENEFICIALLY OR CONSTRUCTIVELY OWN SERIES M PREFERRED STOCK WHICH
CAUSES OR WILL CAUSE A PERSON TO BENEFICIALLY OR CONSTRUCTIVELY OWN SERIES M
PREFERRED STOCK IN EXCESS OF THE ABOVE LIMITATIONS MUST IMMEDIATELY NOTIFY THE
CORPORATION. IF ANY OF THE RESTRICTIONS ON TRANSFER OR OWNERSHIP ARE VIOLATED,
THE SERIES M PREFERRED STOCK REPRESENTED HEREBY WILL BE AUTOMATICALLY
TRANSFERRED TO THE TRUSTEE OF A TRUST FOR THE BENEFIT OF ONE OR MORE CHARITABLE
BENEFICIARIES. IN ADDITION, THE CORPORATION MAY REDEEM SHARES UPON THE TERMS AND
CONDITIONS SPECIFIED BY THE BOARD OF DIRECTORS IN ITS SOLE DISCRETION IF THE
BOARD OF DIRECTORS DETERMINES THAT OWNERSHIP OR A TRANSFER OR OTHER EVENT MAY
VIOLATE THE RESTRICTIONS DESCRIBED ABOVE. FURTHERMORE, UPON THE OCCURRENCE OF
CERTAIN EVENTS, ATTEMPTED TRANSFERS IN VIOLATION OF THE RESTRICTIONS DESCRIBED
ABOVE MAY BE VOID AB INITIO. ALL TERMS IN THIS LEGEND WHICH ARE DEFINED IN THE
ARTICLES SUPPLEMENTARY FOR THE SERIES M PREFERRED STOCK SHALL HAVE THE MEANINGS
ASCRIBED TO THEM IN SUCH ARTICLES SUPPLEMENTARY AS THE SAME MAY BE AMENDED FROM
TIME TO TIME, A COPY OF WHICH, INCLUDING THE RESTRICTIONS ON TRANSFER AND
OWNERSHIP WILL BE FURNISHED TO EACH HOLDER OF SERIES M PREFERRED STOCK ON
REQUEST AND WITHOUT CHARGE. REQUESTS FOR SUCH A COPY MAY BE DIRECTED TO THE
SECRETARY OF THE CORPORATION AT ITS PRINCIPAL OFFICE.

       IF THE CERTIFICATE REPRESENTS SHARES OF COMMON STOCK, THE FOLLOWING
                            RESTRICTIONS SHALL APPLY:

      THE SHARES OF COMMON STOCK REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO
RESTRICTIONS ON BENEFICIAL AND CONSTRUCTIVE OWNERSHIP AND TRANSFER FOR THE
PURPOSE OF THE CORPORATION'S MAINTENANCE OF ITS STATUS AS A REAL ESTATE
INVESTMENT TRUST UNDER THE INTERNAL REVENUE CODE OF 1986, AS AMENDED (THE
"CODE"). SUBJECT TO CERTAIN FURTHER RESTRICTIONS AND EXCEPT AS EXPRESSLY
PROVIDED IN THE CORPORATION'S CHARTER, (I) NO PERSON MAY BENEFICIALLY OR
CONSTRUCTIVELY OWN SHARES OF THE CORPORATION'S COMMON STOCK IN EXCESS OF 9.8%
(BY VALUE OR BY NUMBER OF SHARES, WHICHEVER IS MORE RESTRICTIVE) OF THE
OUTSTANDING COMMON STOCK OF THE CORPORATION; (II) NO PERSON MAY BENEFICIALLY OR
CONSTRUCTIVELY OWN SHARES OF COMMON STOCK THAT WOULD RESULT IN THE CORPORATION
BEING "CLOSELY HELD" UNDER SECTION 856(h) OF THE CODE OR OTHERWISE CAUSE THE
CORPORATION TO FAIL TO QUALIFY AS A REIT; AND (III) NO PERSON MAY TRANSFER
SHARES OF COMMON STOCK IF SUCH TRANSFER WOULD RESULT IN THE CAPITAL STOCK OF THE
CORPORATION BEING OWNED BY FEWER THAN 100 PERSONS. ANY PERSON WHO BENEFICIALLY
OR CONSTRUCTIVELY OWNS OR ATTEMPTS TO BENEFICIALLY OR CONSTRUCTIVELY OWN SHARES
OF COMMON STOCK IN VIOLATION OF THE ABOVE LIMITATIONS MUST IMMEDIATELY NOTIFY
THE CORPORATION. IF ANY OF THE RESTRICTIONS ON TRANSFER OR OWNERSHIP ARE
VIOLATED, THE SHARES OF COMMON STOCK REPRESENTED HEREBY WILL BE AUTOMATICALLY
TRANSFERRED TO THE TRUSTEE OF A TRUST FOR THE BENEFIT OF ONE OR MORE CHARITABLE
BENEFICIARIES. IN ADDITION, THE CORPORATION MAY REDEEM SHARES UPON THE TERMS AND
CONDITIONS SPECIFIED BY THE BOARD OF DIRECTORS IN ITS SOLE DISCRETION IF THE
BOARD OF DIRECTORS DETERMINES THAT OWNERSHIP OR A TRANSFER OR OTHER EVENT MAY
VIOLATE THE RESTRICTIONS DESCRIBED ABOVE. FURTHERMORE, UPON THE OCCURRENCE OF
CERTAIN EVENTS, ATTEMPTED TRANSFERS IN VIOLATION OF THE RESTRICTIONS DESCRIBED
ABOVE MAY BE VOID AB INITIO. ALL TERMS IN THIS LEGEND THAT ARE DEFINED IN THE
CHARTER OF THE CORPORATION SHALL HAVE THE MEANINGS ASCRIBED TO THEM IN THE
CHARTER OF THE CORPORATION AS THE SAME MAY BE AMENDED FROM TIME TO TIME, A COPY
OF WHICH, INCLUDING THE RESTRICTIONS ON TRANSFER AND OWNERSHIP, WILL BE
FURNISHED TO EACH HOLDER OF SHARES OF COMMON STOCK ON REQUEST AND WITHOUT
CHARGE. REQUESTS FOR SUCH A COPY MAY BE DIRECTED TO THE SECRETARY OF THE
CORPORATION AT ITS PRINCIPAL OFFICE.

      The following abbreviations, when used in the inscription on the face of
this certificate, shall be construed as though they were written out in full
according to applicable laws or regulations:

TEN COM - as tenants in common            UNIF GIFT MIN ACT            Custodian
TEN ENT - as tenants by the entireties                     ------------
JT TEN  - as joint tenants with right of                   (Custodian)   (Minor)
          survivorship and not as tenants                  under Uniform Gifts
          in common                                        to Minors Act of

                                                           --------------------
                                                          (State)


     Additional abbreviations may also be used though not in the above list.

  FOR VALUE RECEIVED,                               DOES HEREBY SELL, ASSIGN AND
TRANSFER UNTO

PLEASE INSERT SOCIAL SECURITY OR OTHER
   IDENTIFYING NUMBER OF ASSIGNEE



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  (Please Print or Typewrite Name and Address, Including Zip Code, of Assignee)

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of the 6-3/4% Series M Cumulative Redeemable Preferred Stock represented by the
within Certificate and does hereby irrevocably constitute and appoint

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to transfer the said stock on the books of the within named Corporation with
full power of substitution in the premises.

Dated
      --------------
                                                     X
                                                      --------------------------
                                                     X
                                                      --------------------------

                                        NOTICE: THE SIGNATURE TO THIS ASSIGNMENT
                                                MUST CORRESPOND WITH THE NAMES
                                                AS WRITTEN UPON THE FACE OF THE
                                                CERTIFICATE IN EVERY PARTICULAR,
                                                WITHOUT ALTERATION OR
                                                ENLARGEMENT OR ANY CHANGE
                                                WHATEVER.


Signature(s) Guaranteed

By
  ----------------------------
THE SIGNATURE(S) MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS,
STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN
AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO S.E.C. RULE
17Ad-15.