Alexander B. Trowbridge, who briefly served as commerce secretary under President Lyndon B. Johnson and headed the National Association of Manufacturers for a decade, has died at his home in Washington. He was 76.

His family said he died Thursday of Lewy disease, a degenerative brain disorder.

He was a rising young oil executive with Esso Standard Oil in 1965 when he accepted the post of assistant secretary of commerce for domestic and international business.

At 37, Trowbridge succeeded John Connor as commerce secretary in 1967 and served for nine months.

Trowbridge went on to become president of the American Management Association, and in 1970 was named president of the National Industrial Conference Board, a business research group now known as the Conference Board.

Six years later, Connor, then chairman of Allied Chemical, recruited Trowbridge as the company's vice chairman. Allied had dumped pollutants into the James River in Virginia and Trowbridge helped work out a settlement with the government.

In 1978, Trowbridge joined the board of the National Association of Manufacturers, one of the largest and most influential trade associations in the country. He became president in 1980, acting as the organization's spokesman and chief lobbyist.

He left the NAM in 1990 to form a business consulting firm, Trowbridge Partners, Inc.

During his career he served on many corporate and nonprofit boards and advisory councils.

He was a Democratic member of President Reagan's National Commission on Social Security Reform in 1983, and served on the Competitiveness Policy Council from 1991-94.

Born Dec. 12, 1929 in Englewood, N.J., "Sandy" Trowbridge graduated from Philips Academy in Andover, Mass., and from Princeton University.

He served as an officer in the Marine Corps during the Korean War from 1951-53 and received the Bronze Star for combat service as a platoon leader and tactical air observer.

His business career began in 1954 with California Texas Oil Co. and then Esso in various posts in the Far East, Central American and the Caribbean. He became president of Esso Standard Oil (Puerto Rico) in 1963.

He is survived by his wife, Eleanor Kann Hutzler Trowbridge; a sister, Julie Cullen of Brooklin, Maine; a stepsister, Joya Cox of McLean Va.; three children from his first marriage, Stephen Chamberlain Trowbridge of Dallas, Texas, Corrin Scott Trowbridge of Redwood City, Calif., and Kimberly Trowbridge Parent of Greenwich, Conn.; two stepchildren, Barbara Verdaguer of Mousterlin, France, and Charles Hutzler of Beijing, China; and nine grandchildren.