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                                                                 EXHIBIT 99.1


[Department of Justice Letterhead]



FOR IMMEDIATE RELEASE                                                      AT
TUESDAY, MAY 27, 1997                                          (202) 616-2771
                                                           TDD (202) 514-1888


          MARTIN MARIETTA MATERIALS AGREES TO DIVESTITURE IN ORDER TO
                          ACQUIRE AMERICAN AGGREGATES

           Justice Department Requires Producers of Road Construction
                Aggregate in Indianapolis To Modify Merger Deal

     WASHINGTON, D.C. -- Martin Marietta Materials, Inc. will be allowed to go
forward with its planned $234.5 million acquisition of American Aggregates
Corporation, as long as it sells a quarry in the Indianapolis area, the Justice
Department announced today.

     Under a settlement agreement reached today with the Justice Department's
Antitrust Division, Martin Marietta Materials will divest American Aggregates'
Harding Street Quarry in Indianapolis.

     Aggregate is used to manufacture asphalt concrete and ready mix concrete,
which are used to build roads and highways. The Indiana Department of
Transportation, through its contracts for highway construction projects, is the
largest purchaser of aggregate in Marion County. Martin Marietta and American
Aggregates compete in the production of aggregate in the Indianapolis area.

     According to a complaint, filed along with the settlement in 



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U.S. District Court in Indianapolis, the deal as originally proposed would have
allowed Martin Marietta Materials to become the dominant supplier of aggregate
in Marion County, Indiana -- which includes Indianapolis -- and would have
given it the power to increase prices.

     "If Martin Marietta Materials had been permitted to acquire both of the
aggregate quarries owned by American Aggregates in the Indianapolis area, the
citizens of Marion County would have had to pay higher prices for the aggregate
used to build their roads," said Joel I. Klein, Acting Assistant Attorney
General of the Department's Antitrust Division, "This settlement preserves
competition and protects customers from higher aggregate prices."

     American Aggregates is a subsidiary of CSR America Inc., a Georgia-based
company. CSR America is a subsidiary of CSR Limited of Australia. American
Aggregates' sales in 1996 were $120 million. 

     Martin Marietta Materials is a North Carolina corporation with
headquarters in Raleigh, North Carolina. Its sales in 1995 were $660 million. 

     As required by the Tunney Act, the proposed consent decree will be
published in the Federal Register, along with the Department's competitive
impact statement. Any person may submit written comments concerning the
proposed decree during a 60-day comment period to J. Robert Kramer, Litigation
II Section, Antitrust Division, U.S. Department of Justice, 1401 H St., N.W., 


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Suite 3000, Washington, D.C. 20530.

    At the conclusion of the 60-day comment period, the Court may enter the
consent decree upon its finding that it serves the public interest.


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