Peter Mennin, 60, president of the Juilliard School of Music in New York City since 1962 and one of America's most prolific symphonic composers, died of cancer June 17 at Columbia-Presbyterian Hospital in New York City.

Over a 40-year period beginning in 1941, Dr. Mennin composed romantic symphonic works influenced by 19th century composers. His work has been described as strongly romantic in its inspiration.

He wrote nine symphonies, completing the last in 1981, as well as sonatas, cantatas, concertos for piano and cello and chamber music. The allegro movement of his Symphony No. 2 in 1943 won the first George Gershwin Memorial Award. His other works included the cantata "The Christmas Story" in 1949 and the orchestral work "Moby Dick" in 1952.

The New York Philharmonic gave 32 performances of eight of his pieces, including the premieres of his Third and Eight symphonies. His Ninth and last symphony was first performed by the National Symphony in 1981, and was performed by China's Central Philharmonic Orchestra.

Dr. Mennin was a native of Erie, Pa., and lived in Manhattan. He studied at the Oberlin Conservatory of Music and earned his doctorate at the Eastman School of Music in Rochester, N.Y. He had served in the Army Air Forces during World War II.

He taught composition at Juilliard from 1947 to 1958, then served as director of the Peabody Conservatory of Music in Baltimore until returning to the Juilliard as its president.

During his years as Juilliard's president, he supervised the move into its new headquarters in Lincoln Center and oversaw the strengthening of its faculty. He established the Juilliard Theater Center at the school in 1968 and the Amercian Opera Center two years later. In 1972, he started a permanent conducting program.

Survivors include his wife, two children, his mother, and a brother.