RALEIGH, North Carolina (July 25, 2006) - Martin Marietta Materials, Inc. (NYSE:MLM) today announced that it will provide an online Web simulcast of its second-quarter 2006 earnings conference call on Tuesday, August 1, 2006. The Company will release results for the second quarter and six months ended June 30, 2006, that morning before the market opens.

The live broadcast of Martin Marietta Materials' conference call will begin at 2:00 p.m. Eastern Time on August 1, 2006. An online replay will be available approximately two hours following the conclusion of the live broadcast and will continue for one year. A link to these events is available at the Company's website: www.martinmarietta.com.

For those investors without online web access, the conference call may also be accessed by calling 719-457-2649, confirmation number 9647042.

Martin Marietta is the nation's second largest producer of construction aggregates, a leading producer of magnesia-based chemical products and is developing structural composites products for use in a wide variety of industries.