Former U.S. senator A. S. Mike Monroney, 77, a soft-spoken Oklahoma Democrat known for his efforts to make government more efficient, died Wednesday in the Rockville Nursing Home. He had an aneurysm and peneumonia.

Sen. Monroney was a member of Congress for 30 years. He served in the House from 1939 to 1951, then in the Senate until his defeat for reelection in 1968. After leaving Congress, he was a transportation consultant in Washington until retiring in 1974.

His interests in government efficiency began with the Congress itself. As a cochairman of a congressional reorganization committee, he led the fight to streamline operations of standing committees and the hiring of staff experts to aid committee members.

He once said that Congress was trying to do its work "sitting on an old-fashioned bookkeeper's stool with a slant-top-desk, a Civil War ledger and a quill pen."

Another of his interests was aviation. As a young reporter in Oklahoma he had interviewed Charles Lindbergh after the latter's historic flight to Paris in 1927. In 1933, the future senator contributed $12.50 to a fund to finance the round-the-world flight of fellow Oklahoman Wiley Post.

Sen. Monroney became known as "Mr. Aviation" after introducing the 1955 Federal Airport Act to promote civil aviation and the legislation a year later that led to the founding of the Federal Aviation Agency.

Before that, the Civil Aeronautics Board, a part of the Commerce Department, regulated the airline industry. It was felt that a new, independent agency would be free of the nonaviation interests in Commerce. As part of its mission of promoting the efficiency and safety of air travel, the FAA was granted the power to coordinate the airspace between civil and military interests and provide air traffic control regulations.

Sen. Monroney also worked to improve the postal service and the lot of federal workers. He pushed for higher wages for federal employes and led the fight for same-day delivery of first-class mail between major cities by using airplanes.

A measure of his interests were the committees and subcommittees he came to chair. He was cochairman of the congressional reorganization committee in the House during the 1940s and chairman of its Senate counterpart from 1965 to 1969. He was chairman of the Senate aviation subcommittee and the Post Office subcommitee of the Appropriations Committee. He was chairman of the Post Office and Civil Service Committee from 1965 to 1969.

Sen. Monroney was born in Oklahoma City and was a 1924 graduate of the University of Oklahoma, were he was elected to Phi Beta Kappa.

From 1924 to 1928, he worked as a political reporter with the Oklahoma City News and then entered the family furniture business. He was elected president of the Oklahoma City Rotary Club and the Olkahoma City Retailers Association before winning election to the House of Representatives in 1938.

In addition to his work on congressional reform, his 12 years in the House included support for naval expansion and the Lend-Lease Bill prior to World War II. He also supported the Bretton Woods proposals creating the World Bank and International Monetary Fund the Marshall Plan to aid European recovery after the war.

During his years in the Senate, Sen. Monroney favored maintenance of the oil depletion allowance, federal aid to education foreign aid bills and U.S. contributions to the United Nations. He voted for the 1964 Civil Rights Act and the cloture motion to bring the bill to the floor of the Senate. That same year he also supported Medicare and the antipoverty bill. A year later he voted for the Appalachia aid bill.

In the 1950s, he was a staunch opponent of senator Joseph McCarthy (R-Wis.) In 1960, he led the unsuccesful drive to get Adlai E. Stevenson his third nomination as Democratic presidential candidate.

Sen. Monroney was defeated in his reelection fight in 1968. His opponent Henry Bellmon, was the first Republican to be eleted governor of Olklahoma. hHe took jabs at Sen. Monroney's long absences from the state and said that the senator did not even own a house in Oklahoma.

Columnist Williams S. White wrote at the time that Sen. Monroney was "one of a sadly diminishing band who still hold the odd conviction that a senator of the United States owes a high obligation to national welfare -- even in an election year."

While Bellmon campaigned, Sen. Monroney continued to chair his committees and use the power that he had garnered through 18 years of seniority. Bellmon won with 53 percent of the vote on election day.

Sen. Monroney, who lived in Washington, had been a member of the chapter of Washington Cathedral for 25 years.

His survivors include his wife, the former Mary Ellen Mellon, of Washington; a son, Michael, of Bethesda; a sister, Margaret Harbison of Olklahoma City, and five grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Mike Monroney Memorial Fund at Washington Cathedral. c

In Oklahoma City, Gov. George Niegh called Sen. Monroney a "great senator" and ordered all state flags flown at half-staff in his honor.