George M. Bunker, 77, a leading figure in the development of this nation's aerospace industry who took control of the ailing Glenn L. Martin Co. in Baltimore in 1952 and built it into the billion-dollar-a-year Martin Marietta Corp., died of respiratory arrest Nov. 5 at his home in Washington.

Mr. Bunker retired as chairman of Martin Marietta in 1977 and as president of the company in 1972. He is generally credited with guiding the development of the Bethesda-based organization from the production of wartime-vintage seaplanes and bombers during the early 1950s into one of the nation's major defense contractors and technological conglomerates.

It was Mr. Bunker who redirected the company's energies from dependence on aircraft production into a diversified line of such products as missiles, rockets, space-launch vehicles and a variety of electronics systems. When he retired in 1977, Martin Marietta had sales of $1.4 billion and net earnings of $102 million. Sales this year are expected to be in the neighborhood of $4 billion, a company spokesman said.

Mr. Bunker, whose first industrial job was that of a 38-cents-an-hour kettle swabber with Campbell Soup, was 44 when he was invited to assume the presidency of the Martin Co. One of his very first moves was to shift away from aircraft production.

By 1960 he had brought the company to the point where sales had reached $651 million and net earnings were $16.8 million, but all of its business was with the government. That worried Mr. Bunker, and he began looking around for diversification.

After two abortive attempts to merge with Sperry Rand and the General Precision Equipment Corp., he finally engineered a consolidation in 1961 with American Marietta Corp. That same year Mr. Bunker became the first president and chief executive of Martin Marietta, and in 1965 he was named chairman of the board.

Under his stewardship, Martin Marietta opened factories across the country, with products ranging from aluminum and chemicals to cement. In the aerospace field, the company developed the first pilotless bomber, the Matador; a variety of defense and space systems for the military services, including the Pershing and Titan ballistic missiles; space boosters and the Viking landers on Mars.

In 1964, Mr. Bunker was instrumental in launching the Bunker-Ramo Corp., which specialized in the design and installation of control systems requiring electronic computing devices.

George Maverick Bunker was born in Chicago. He graduated from the Massachusetts Institute of Technology. After working for Campbell Soup, he joined the Wilson Meat Packing Co. He then became a partner in the A.T. Kearney Co., a Chicago management engineering firm. In 1942, he joined the Kroger Co., a grocery store chain, as a vice president.

In 1949, he was elected president and general manager of Trailmobile Inc. A subsidiary of Pullman Inc., which manufactured truck trailers, parts and equipment, the company was on the brink of financial collapse when Mr. Bunker assumed control. His record in bringing it to profitability earned him the offer from Martin.

A resident of Washington since the late 1950s, Mr. Bunker was a trustee of George Washington University and a member of the Metropolitan Club and the 1925 F Street Club. He was a golfer and a member of the Burning Tree Club, the Congressional Country Club and Columbia Country Club.

He was also an enthusiastic baseball fan, and during the 1960s he was a minority owner of the old Washington Senators.

His first marriage, to Virginia S. Bunker, ended in divorce, as did his marriage to Sally Bunker.

Survivors include his wife, Natalie Hathaway Keeney Bunker of Washington; a son by his first marriage, Dr. Gerald E. Bunker of Annapolis; three stepchildren, Robert Van Schenck of Gaithersburg, Shawn Crawford of Los Angeles and Claire Mazzonetto of Winter Park, Fla.; a sister, Mrs. Donald D. Carrick of Toronto; seven grandchildren, and six step-grandchildren.