SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                               (Amendment No. __)*

                         Reckson Associates Realty Corp.
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                                (Name of Issuer)

                      Class A Common Stock, $.01 par value
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                         (Title of Class of Securities)

                                    75621K106
                                 --------------
                                 (CUSIP Number)

                                  May 31, 2003
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             (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

                  |X|      Rule 13d-1(b)
                  [ ]      Rule 13d-1(c)
                  [ ]      Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).




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CUSIP No.  75621K106            13G                   Page 2 of 6 Pages
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 1.   Names of Reporting Persons.
      I.R.S. Identification Nos. of Above Persons (entities only).

               Security Capital Research & Management Incorporated
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 2.   Check the Appropriate Box If a Member of a Group (See Instructions)
                                                                (a) [_]
                                                                (b) [_]
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 3.   SEC Use Only

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 4.   Citizenship or Place of Organization
        Delaware
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                     5.   Sole Voting Power
   NUMBER OF               -0- shares of Common Stock
    SHARES         -------------------------------------------------------------
 BENEFICIALLY        6.   Shared Voting Power
   OWNED BY                4,985,706 shares of Common Stock
     EACH          -------------------------------------------------------------
  REPORTING          7.   Sole Dispositive Power
    PERSON                 -0- shares of Common Stock
     WITH          -------------------------------------------------------------
                     8.     Shared Dispositive Power
                             4,985,706 shares of Common Stock
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 9.   Aggregate Amount Beneficially Owned by Each Reporting Person

           4,985,706 shares of Common Stock
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10.   Check Box If the Aggregate Amount in Row (9) Excludes Certain Shares

                                                                    [_]
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11.   Percent of Class Represented by Amount in Row (9)

                      10.35% of the shares of Common Stock
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12.   Type of Reporting Person*

                         IA
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                      *SEE INSTRUCTIONS BEFORE FILLING OUT!



Item 1(a).        Name of Issuer:

                  Reckson Associates Realty Corp.

        (b).      Address of Issuer's Principal Executive Offices:

                  225 Broadhollow Road, Melville, New York 11747

Item 2(a).        Name of Person Filing:

                  Security Capital Research & Management Incorporated, a
                  corporation organized and existing under the laws of Delaware
                  ("SCR&M").

        (b).      Address of Principal Business Office or, if None, Residence:

                  11 South LaSalle Street, 2nd Floor, Chicago, Illinois 60603

        (c).      Citizenship:

                  Delaware

        (d).      Title of Class of Securities:

                  Class A Common Stock, $.01 par value per share

        (e).      CUSIP Number:

                  75621K106

Item 3. If this statement is filed pursuant to Rule 13d-1(b), or 13d-2(b) or
        (c), check whether the person filing is a:

        (a)  [ ] Broker or dealer registered under Section 15 of the
                 Exchange Act;

        (b)  [ ] Bank as defined in Section 3(a)(6) of the Exchange Act;

        (c)  [ ] Insurance company as defined in Section 3(a)(19) of the
                 Exchange Act;

        (d)  [ ] Investment company registered under Section 8 of the Investment
                 Company Act;

        (e)  |X| An investment adviser in accordance with Rule
                 13d-1(b)(1)(ii)(E);

        (f)  [ ] An employee benefit plan or endowment fund in accordance with
                 Rule 13d-1(b)(1)(ii)(F);

        (g)  [ ] A parent holding company or control person in accordance with
                 Rule 13d-1(b)(1)(ii)(G);

        (h)  [ ] A savings association as defined in Section 3(b) of the Federal
                 Deposit Insurance Act;

        (i)  [ ] A church plan that is excluded from the definition of an
                 investment company under Section 3(c)(14) of the Investment
                 Company Act;

        (j)  [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).




Item 4.   Ownership.

     (a). Amount Beneficially Owned:

               SCR&M beneficially owns 4,985,706 shares of Common Stock.

     (b). Percent of Class:

               10.35% of the shares of Common Stock determined in accordance
               with the provisions of Rule 13d-1 promulgated under the Act.

     (c). Number of shares as to which such person has:

               (i).   Sole power to vote or to direct the vote:

                      None.

               (ii).  Shared power to vote or to direct the vote:

                      SCR&M has shared power to vote or direct the vote of
                      4,985,706 shares of Common Stock.

               (iii). Sole power to dispose or to direct the disposition of:

                      None.

               (iv).  Shared power to dispose or to direct the disposition of:

                      SCR&M has shared power to dispose or to direct the
                      isposition of 4,985,706 shares of Common Stock.

Item 5.   Ownership of Five Percent or Less of a Class.

               Not applicable.

Item 6.   Ownership of More than Five Percent on Behalf of Another Person.

               Various persons have the right to receive or the power to
               direct the receipt of dividends from, or the proceeds from the
               sale of, the Common Stock. No one person's interest in the Common
               Stock is more than five percent of the total outstanding shares
               of Common Stock.

Item 7. Identification and Classification of the Subsidiary Which Acquired the
        Security Being Reported on By the Parent Holding Company.

               Not applicable.




Item 8. Identification and Classification of Members of the Group.

     Not applicable.

Item 9. Notice of Dissolution of a Group.

     Not applicable.

Item 10. Certification.

     By signing below I certify that, to the best of my knowledge and belief,
the securities referred to above were acquired and are held in the ordinary
course of business and were not acquired and are not held for the purpose of or
with the effect of changing or influencing the control/ of the issuer of the
securities and were not acquired and are not held in connection with or as a
participant in any transaction having that purpose or effect.



                                    SIGNATURE

     After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

Date: June 10, 2003

                                         SECURITY CAPITAL RESEARCH & MANAGEMENT
                                         INCORPORATED




                                         By: /s/ David T. Novick
                                             -----------------------------------
                                             Name:  David T. Novick
                                             Title: General Counsel