<PAGE>

                                                                     EXHIBIT 4.3

UNLESS THIS SECURITY IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE
DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), 55 WATER STREET, NEW
YORK, NEW YORK, TO THE ISSUER (AS DEFINED BELOW) OR ITS AGENT FOR REGISTRATION
OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN
THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER
ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER,
PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS
WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST
HEREIN.

THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING SET FORTH IN THE INDENTURE
HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF DTC OR A NOMINEE OF
DTC. THIS SECURITY IS EXCHANGEABLE FOR SECURITIES REGISTERED IN THE NAME OF A
PERSON OTHER THAN DTC OR ITS NOMINEE ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED
IN THE INDENTURE, AND MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY DTC TO A
NOMINEE OF DTC OR ANOTHER NOMINEE OF DTC OR BY DTC OR ITS NOMINEE TO A SUCCESSOR
DEPOSITORY OR ITS NOMINEE.

Registered No.  1                                              PRINCIPAL AMOUNT
CUSIP No.:  55448Q AE6                                         $300,000,000

                             MACK-CALI REALTY, L.P.

                               7.75% NOTE DUE 2011


            MACK-CALI REALTY, L.P., a limited partnership duly organized and
existing under the laws of the State of Delaware (herein referred to as the
"ISSUER" which term shall include any Successor Person under the Indenture
hereinafter referred to), for value received, hereby promises to pay to CEDE &
CO., or registered assigns, upon presentation, the principal sum of THREE
HUNDRED MILLION DOLLARS on February 15, 2011, and to pay interest on the
outstanding principal amount thereon from January 29, 2001, or from the
immediately preceding Interest Payment Date to which interest has been paid or
duly provided for, semi-annually in arrears on February 15 and August 15 in each
year, commencing August 15, 2001, at the rate of 7.75% per annum, until the
entire principal hereof is paid or made available for payment. The interest so
payable and punctually paid or duly provided for on any Interest Payment Date
will, as provided in the Indenture, be paid to the Person in whose name this
Security is registered at the close of business on the Regular Record Date for
such interest which shall be the February 1 or August 1 (whether or not a
Business Day), as the case may be, next preceding such Interest Payment Date.
Any such interest not so punctually paid or duly provided for shall forthwith
cease to be payable to the Holder on such Regular Record Date, and may either be
paid to the Person in whose name this Security is registered at the close of
business on a Special Record Date for the payment of such Defaulted Interest to
be fixed by the Trustee, notice whereof shall be given to Holders of the
Securities not


<PAGE>

more than 15 days and not less than 10 days prior to such Special Record Date,
or may be paid at any time in any other lawful manner not inconsistent with the
requirements of any securities exchange on which the Securities may be listed,
and upon such notice as may be required by such exchange, all as more fully
provided in the Indenture. Payment of the principal of and interest on this
Security will be made at the office or agency maintained for that purpose in the
City of Wilmington, Delaware or elsewhere as provided in the Indenture, in such
coin or currency of the United States of America as at the time of payment is
legal tender for payment of public and private debts; PROVIDED, HOWEVER, that at
the option of the Issuer payments of principal and interest on the Notes (other
than payments of principal and interest due at Maturity) may be made (i) by
check mailed to the address of the Person entitled thereto as such address shall
appear in the Security Register or (ii) by wire transfer to an account of the
Person entitled thereto located within the United States.

            Securities of this series are one of a duly authorized issue of
securities of the Issuer (herein called the "SECURITIES"), issued and to be
issued in one or more series under an Indenture, dated as of March 16, 1999,
among the Issuer, Mack-Cali Realty Corporation and Wilmington Trust Company
(herein called the "TRUSTEE", which term includes any successor trustee under
the Indenture), as supplemented by Supplemental Indenture No. 1, dated as of
March 16, 1999, as further supplemented by Supplemental Indenture No. 2, dated
as of August 2, 1999, as further supplemented by Supplemental Indenture No. 3,
dated as of December 21, 2000, and as further supplemented by Supplemental
Indenture No. 4, dated as of January 29, 2001 (as so supplemented, herein called
the "INDENTURE"), between the Issuer and the Trustee to which Indenture and all
indentures supplemental thereto reference is hereby made for a statement of the
respective rights, limitations of rights, duties and immunities thereunder of
the Issuer, the Trustee and the Holders of the Securities and of the terms upon
which the Securities are authenticated and delivered. This Security is one of
the series designated in the first page thereof, limited in aggregate principal
amount to $300,000,000, except as the aggregate principal amount may be
increased pursuant to Section 2.2 of Supplemental Indenture No. 4 referred to
above.

            Securities of this series may be redeemed at any time at the option
of the Issuer, in whole or in part, upon notice of not more than 60 nor less
than 30 days prior to the Redemption Date, at a redemption price equal to the
sum of (i) the principal amount of the Securities being redeemed plus accrued
and unpaid interest thereon up to but not including the Redemption Date and (ii)
the Make-Whole Premium, if any, with respect to such Securities.

            The Indenture contains provisions for defeasance at any time of (a)
the entire indebtedness of the Issuer on this Security and (b) certain
restrictive covenants and the related defaults and Events of Default applicable
to the Issuer, in each case, upon compliance by the Issuer with certain
conditions set forth in the Indenture, which provisions apply to this Security.


                                       2
<PAGE>

            If an Event of Default with respect to the Securities shall occur
and be continuing, the principal of the Securities may be declared due and
payable in the manner and with the effect provided in the Indenture.

            As provided in and subject to the provisions of the Indenture, the
Holder of this Security shall not have the right to institute any proceeding
with respect to the Indenture or for the appointment of a receiver or trustee or
for any other remedy thereunder, unless such Holder shall have previously given
written notice to the Trustee of a continuing Event of Default with respect to
the Securities, the Holders of not less than a majority in principal amount of
the Securities of this series at the time Outstanding shall have made written
request to the Trustee to institute proceedings in respect of such Event of
Default as Trustee and offered the Trustee reasonable indemnity and the Trustee
shall not have received from the Holders of a majority in principal amount of
Securities of this series at the time Outstanding a direction inconsistent with
such request, and shall have failed to institute any such proceeding, for 60
days after receipt of such notice, request and offer of indemnity. The foregoing
shall not apply to any suit instituted by the Holder of this Security for the
enforcement of any payment of principal hereof or any interest on or after the
respective due dates expressed herein.

            The Indenture permits, with certain exceptions as therein provided,
the amendment thereof and the modification of the rights and obligations of the
Issuer and the rights of the Holders of the Securities of each series to be
affected under the Indenture at any time by the Issuer and the Trustee with the
consent of the Holders of not less than a majority in principal amount of the
Outstanding Securities of each series of Securities then Outstanding affected
thereby. The Indenture also contains provisions permitting the Holders of
specified percentages in principal amount of the Securities of each series at
the time Outstanding, on behalf of the Holders of all Securities of such series,
to waive compliance by the Issuer with certain provisions of the Indenture and
certain past defaults under the Indenture and their consequences. Any such
consent or waiver by the Holder of this Security shall be conclusive and binding
upon such Holder and upon all future Holders of this Security and of any
Security issued upon the registration of transfer hereof or in exchange herefor
or in lieu hereof, whether or not notation of such consent or waiver is made
upon this Security.

            No reference herein to the Indenture and no provision of this
Security or of the Indenture shall alter or impair the obligation of the Issuer,
which is absolute and unconditional, to pay the principal of (and Make-Whole
Premium, if any) and interest on this Security at the times, place and rate, and
in the coin or currency, herein prescribed.

            As provided in the Indenture and subject to certain limitations
therein set forth, the transfer of this Security is registrable in the Security
Register, upon surrender of this Security for registration of transfer at the
office or agency of the Issuer in any Place of Payment where the principal of
(and Make-Whole Premium, if


                                       3
<PAGE>

any) and interest on this Security are payable, duly endorsed by, or accompanied
by a written instrument of transfer in form satisfactory to the Issuer and the
Security Registrar duly executed by the Holder hereof or his attorney duly
authorized in writing, and thereupon one or more new Securities of this series,
of authorized denominations and for the same aggregate principal amount, will be
issued to the designated transferee or transferees.

            Except as set forth in Section 302 of the Indenture, the Securities
of this series are issuable only in registered form without coupons in
denominations of $1,000 and any integral multiple thereof. As provided in the
Indenture and subject to certain limitations therein set forth, Securities of
this series are exchangeable for a like aggregate principal amount of Securities
of this series of a different authorized denomination, as requested by the
Holder surrendering the same.

            No service charge shall be made for any such registration of
transfer or exchange, but the Issuer may require payment of a sum sufficient to
cover any tax or other governmental charge payable in connection therewith.

            Prior to due presentment of this Security for registration of
transfer, the Issuer, the Trustee and any agent of the Issuer or the Trustee may
treat the Person in whose name this Security is registered as the owner hereof
for all purposes, whether or not this Security be overdue, and neither the
Issuer, the Trustee nor any such agent shall be affected by notice to the
contrary.

            No recourse under or upon any obligation, covenant or agreement
contained in the Indenture or in this Security, or because of any indebtedness
evidenced hereby or thereby, shall be had against any promoter, as such, or
against any past, present or future shareholder, officer or director, as such,
of the Issuer or of any successor, either directly or through the Issuer or any
successor, under any rule of law, statute or constitutional provision or by the
enforcement of any assessment or by any legal or equitable proceeding or
otherwise, all such liability being expressly waived and released by the
acceptance of this Security by the Holder thereof and as part of the
consideration for the issue of the Securities of this series.

            All capitalized terms used in this Security which are defined in the
Indenture shall have the meanings assigned to them in the Indenture.

            THE INDENTURE AND THE SECURITIES, INCLUDING THIS SECURITY, SHALL BE
GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

            Pursuant to a recommendation promulgated by the Committee on Uniform
Security Identification Procedures, the Issuer has caused "CUSIP" numbers to be
printed on the Securities of this series as a convenience to the Holders of such
Securities. No representation is made as to the correctness or accuracy of such
CUSIP numbers as printed on the Securities, and reliance may be placed only on
the other identification numbers printed hereon.


                                       4
<PAGE>

            Unless the certificate of authentication hereon has been executed by
or on behalf of the Trustee by manual signature, this Security shall not be
entitled to any benefit under the Indenture or be valid or obligatory for any
purpose.


             [REMAINDER OF PAGE INTENTIONALLY BLANK; SIGNATURE PAGE
                                    FOLLOWS]






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<PAGE>



            IN WITNESS WHEREOF, MACK-CALI REALTY, L.P. has caused this
instrument to be duly executed.

Dated: January 29, 2001

                                   MACK-CALI REALTY, L.P.

                                   By: Mack-Cali Realty Corporation, its
                                       General Partner


                                   By: _____________________________
                                   Name:  Barry Lefkowitz
                                   Title: Executive Vice President and
                                          Chief Financial Officer


Attest:

_______________________________
Name:  Roger W. Thomas
Title: Executive Vice President,
       General Counsel and Secretary



TRUSTEE'S CERTIFICATE OF AUTHENTICATION:

            This is one of the Securities of the series designated therein
referred to in the within-mentioned Indenture.

                                   WILMINGTON TRUST COMPANY,
                                      as Trustee


                                   By:___________________________
                                      Authorized Signatory



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<PAGE>

================================================================================

                                 ASSIGNMENT FORM

                   FOR VALUE RECEIVED, the undersigned hereby
                        sells, assigns and transfers unto

  PLEASE INSERT SOCIAL
  SECURITY OR OTHER IDENTIFYING
  NUMBER OF ASSIGNEE
____________________________________

____________________________________ -------------------------------------------


--------------------------------------------------------------------------------
              (Please Print or Typewrite Name and Address including
                              Zip Code of Assignee)

--------------------------------------------------------------------------------
the within Security of Mack-Cali Realty, L.P. and hereby does irrevocably
constitute and appoint

_______________________________________________________________________ Attorney
to transfer said Security on the books of the within-named Issuer with full
power of substitution in the premises.

Dated:  ______________  _____________________________________________

                        _____________________________________________

NOTICE: The signature to this assignment must correspond with the name as it
appears on the first page of the within Security in every particular, without
alteration or enlargement or any change whatever.

                        Signature(s) must be guaranteed by an institution which
                        is a member of one of the following recognized signature
                        Guarantee Programs: (i) The Securities Transfer Agent
                        Medallion Program (STAMP); (ii) The New York Stock
                        Exchange Medallion Program (MNSP); (iii) The Stock
                        Exchange Medallion Program (SEMP); or (iv) another
                        guarantee program acceptable to the Trustee.

                              _______________________________
                               Signature Guarantee


================================================================================



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