As filed with the Securities and Exchange Commission on February 28, 1997
                           Registration No. 33-58341


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

                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549

                            ____________________

                        POST-EFFECTIVE AMENDMENT NO. 1
                                      TO
                                   FORM S-8
                            REGISTRATION STATEMENT
                                     UNDER
                          THE SECURITIES ACT OF 1933

                             _____________________

                      ALEXANDER & ALEXANDER SERVICES INC.
            (Exact name of registrant as specified in its charter)

        MARYLAND                                                52-0969822
  (State or other jurisdiction of                             (I.R.S. Employer
  incorporation or organization)                             Identification No.)
       

                          1185 AVENUE OF THE AMERICAS
                              NEW YORK, NEW YORK
                   (Address of principal executive offices)

      NON-EMPLOYEE DIRECTORS DEFERRED PLAN/NON-EMPLOYEE COMPENSATION PLAN
                           (Full title of the plan)

                       MICHAEL D. O'HALLERAN, PRESIDENT
                      ALEXANDER & ALEXANDER SERVICES INC.
                          1185 AVENUE OF THE AMERICAS
                              NEW YORK, NEW YORK
                               (Name and address
                             of agent for service)

                                (212) 444-4500
                       (Telephone number, including area
                          code, of agent for service)

                                   Copy to:

                             FREDERICK C. LOWINGER
                                SIDLEY & AUSTIN
                           ONE FIRST NATIONAL PLAZA
                            CHICAGO, ILLINOIS 60603
                                (312) 853-7000


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

 
          This Registration Statement No. 33-58341 (the "Registration
Statement") registered an aggregate of 300,000 shares of Common Stock, par value
$1.00 per share, and associated preferred stock purchase rights (collectively,
the "Securities"), of Alexander & Alexander Services Inc. (the "Registrant").

          On February 21, 1997, the Registrant became a wholly-owned subsidiary
of Aon Corporation following a merger. As a result of the merger, the offering
of the Securities has been terminated and, in accordance with Item 512(a)(3) of
Regulation S-K under the Securities Act of 1933, as amended, this Post-Effective
Amendment is being filed.

                                     II-2

 
                                  SIGNATURES

          Pursuant to the requirements of the Securities Act of 1933, as
amended, the Registrant has duly caused this Post-Effective Amendment No. 1 to
the Registration Statement to be signed on its behalf by the undersigned
thereunto duly authorized, in the City of New York, State of New York, on
February 28, 1997.


                                   ALEXANDER & ALEXANDER SERVICES INC.


                                   By: /s/ Michael D. O'Halleran
                                       -------------------------
                                           Michael D. O'Halleran
                                           President


                               POWER OF ATTORNEY

          KNOW ALL MEN BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Michael D. O'Halleran and Raymond I.
Skilling, and each of them, his true and lawful attorney-in-fact and agent, with
full power of substitution and resubstitution for him and in his name, place and
stead, in any and all capacities, to sign any and all amendments (including 
post-effective amendments) to this Registration Statement, and to file the same,
with all exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorney-in-fact and
agent full power and authority to do and perform each and every act and thing
requisite and necessary to be done in and about the premises, as fully to all
intents and purposes as he might or could do in person, hereby ratifying and
confirming all that said attorney-in-fact and agent or his substitute may
lawfully do or cause to be done by virtue hereof.

          Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on February 28, 1997.


Name                                      Title
- ----                                      -----

                                       
/s/ Michael D. O'Halleran              President and     
- ---------------------------            Director (Principal                
    Michael D. O'Halleran              Executive Officer)

                                       
/s/ Richard P. Sneeder, Jr.            Vice President and
- ---------------------------            Controller (Principal
    Richard P. Sneeder, Jr.            Accounting Officer)


/s/ Patrick G. Ryan                    Director
- ---------------------------
    Patrick G. Ryan                    
                                   
                                   
/s/ Harvey N. Medvin                   Director
- ---------------------------
    Harvey N. Medvin                   
                                   
                                   
/s/ Raymond I. Skilling                Director 
- ---------------------------
    Raymond I. Skilling