As filed with the Securities and Exchange Commission on March 28, 1995.

                                                       Registration No. 33-60486

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                       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

                              --------------------

                          MARTIN MARIETTA CORPORATION
             (Exact name of registrant as specified in its charter)


       Maryland                                               52-1801551
(State or other jurisdiction of                             (I.R.S. Employer    
incorporation or organization)                             Identification No.)  

                              6801 Rockledge Drive
                            Bethesda, Maryland 20817
                    (Address of principal executive offices)



                          Martin Marietta Corporation
                            Performance Sharing Plan
                            (Full title of the plan)



                           Stephen M. Piper, Esquire
                           Assistant General Counsel
                          Martin Marietta Corporation
                              6801 Rockledge Drive
                            Bethesda, Maryland 20817
                                 (301) 897-6000
           (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)
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                             EXPLANATORY STATEMENT
                             ---------------------

     On March 15, 1995, Martin Marietta Corporation ("Martin Marietta") and
Lockheed Corporation ("Lockheed") consummated the combination of the Lockheed
businesses with the businesses of Martin Marietta (the "Combination") on the
terms and conditions more fully described in Registration Statement No. 33-57645
on Form S-4 filed by Lockheed Martin Corporation ("Lockheed Martin") with the
Commission on February 9, 1994.  As a result of the Combination, each share of
Martin Marietta common stock and each stock option outstanding under Martin
Marietta's employee benefit and compensatory plans was converted into the right
to receive one share of Lockheed Martin common stock or one Lockheed Martin
stock option, as the case may be, and each share of Lockheed common stock and
each stock option outstanding under Lockheed's employee benefit and compensatory
plans was converted into the right to receive 1.63 shares of Lockheed Martin
common stock or Lockheed Martin stock options, as the case may be.  In addition,
upon consummation of the Combination, each of Martin Marietta and Lockheed
became a wholly-owned subsidiary of Lockheed Martin.

     Shares previously registered by Martin Marietta for use in connection
with the Martin Marietta Corporation Performance Sharing Plan (the "Plan") on
Registration Statement No. 33-60486 on Form S-8 (the "Registration Statement")
and not already issued will not be issued by Martin Marietta and, pursuant to
Martin Marietta's undertakings in the Registration Statement, Martin Marietta
files this Post-Effective Amendment No. 1 thereto to remove from registration
the shares of Martin Marietta common stock registered thereunder which had not
been issued as of closing of the Combination.

     Lockheed Martin has registered shares of its common stock to be issued in
conjunction with the Plan.


Item 8.        Exhibits
- ------         --------

Exhibit No.    Description
- -----------    -----------

     25        Powers of Attorney (incorporated by reference to Exhibit 25 to
               Registration Statement on Form S-8 (Reg. No. 33-60486) filed with
               the Commission on April 2, 1993).

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                                   SIGNATURES


     Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Post-Effective
Amendment No. 1 to Registration Statement No. 33-60486 to be signed on its
behalf by the undersigned, thereunto duly authorized, in the County of
Montgomery, State of Maryland on the 28th day of March, 1995.

                                       MARTIN MARIETTA CORPORATION        
                                                                          
Date:  March 28, 1995                  By: /s/Jay A. Brozost              
                                              --------------              
                                               Jay A. Brozost             
                                               Vice President and         
                                                 Associate General Counsel 


Pursuant to the requirements of the Securities Act of 1933, this Post-Effective
Amendment No. 1 to Registration Statement No. 33-60486 has been signed by the
following persons in the capacities and on the dates indicated.
 
       Signature                      Title                Date
       ---------                      -----                ----              
 
/s/Norman R. Augustine        Chairman and Chief      March 28, 1995
   -------------------------  Executive Officer         
   Norman R. Augustine*       (Principal Executive       
                              Officer)                   
 
/s/Marcus C. Bennett          Senior Vice President   March 28, 1995
   -------------------------  and Chief Financial         
   Marcus C. Bennett*         Officer (Principal           
                              Financial Officer and        
                              Principal Accounting         
                              Officer)                     
                                                           
/s/Lamar Alexander            Director                March 28, 1995
   -------------------------
   Lamar Alexander*
 
/s/A. James Clark             Director                March 28, 1995
   -------------------------
   A. James Clark*
 
/s/Edwin I. Colodny           Director                March 28, 1995
   -------------------------
   Edwin I. Colodny*
 
/s/James L. Everett, III      Director                March 28, 1995
   -------------------------
   James L. Everett, III*
 
/s/Edward L. Hennessy, Jr.    Director                March 28, 1995
   -------------------------
   Edward L. Hennessy, Jr.*
 

                                      -3-

 
       Signature                      Title                Date
       ---------                      -----                ----              
 
/s/Caleb B. Hurtt             Director                March 28, 1995
   -------------------------
   Caleb B. Hurtt*
 
/s/Gwendolyn S. King          Director                March 28, 1995
   -------------------------
   Gwendolyn S. King*
 
/s/Melvin R. Laird            Director                March 28, 1995
   -------------------------
   Melvin R. Laird*
 
/s/Gordon S. Macklin          Director                March 28, 1995
   -------------------------
   Gordon S. Macklin*
 
/s/Allen E. Murray            Director                March 28, 1995
   -------------------------
   Allen E. Murray*
 
/s/John W. Vessey, Jr.        Director                March 28, 1995
   -------------------------
   John W. Vessey, Jr.*
 
/s/A. Thomas Young            Director                March 28, 1995
   -------------------------
   A. Thomas Young*


* By: /s/Stephen M. Piper     March 28, 1995
         ----------------                
         Stephen M. Piper
         Attorney-in-Fact**


** By authority of powers of attorney filed with this registration statement.

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