Robert L. Augenblick, 65, president of the Investment Company Institute, died of cancer March 16 at his home in Washington.

He had joined the institute as general counsel in 1962 and became its president in 1966. The national association for the mutual fund industry, it moved its offices from New York City to Washington in 1970.

Mr. Augenblick testified frequently before congressional committees on legislation concerning mutual funds and the securities industry. He also had lectured widely on securities law in this country and abroad.

Born in Newark, N.J. he was a graduate of Brown University and Harvard law school, where he was editor of the Harvard Law Review.

During World War II, Mr. Augenblick served as a major with the Army Air Corps in the China-Burma-India Theater. He received the Bronze Star. After the war, he practiced law in New York City.

He is survived by his wife, Elizabeth Rivinus Leydon Augenblick, of the home; four children, Mark, of Bethesda; Peter of New Hope, Pa.; Drew of Hartford, Conn, and Katherine Somers, of San Francisco, and four stepchildren, John K. Leydon Jr., of New Hope; Christopher Leydon, of Lahaska, Pa.; Edward Leydon, of New York City, and Lis Goldener.

The family suggests that expressions of sympathy be in the form of contributions to the American Cancer Society or the Sloan-Kettering Institute for Cancer Research.