William P. Sullivan, 60, a partner in the Washington law firm of Baskin & Sears who specialized in transportation law, died of a cerebral hemorrhage Saturday at Suburban Hospital in Bethesda.

Mr. Sullivan, who was born in Nashua, N.H., graduated from St. Anselm's College in Manchester, N.H. During World War II, he was an officer in the Navy and served in Europe and the Pacific.

In 1946, he moved to Washington and earned a law degree at Georgetown University. In 1949, he went to work for the Interstate Commerce Commission, where he became a hearing examiner. He later worked for the Civil Aeronautics Board and then returned to the ICC.

In 1959, Mr. Sullivan entered private practice. He was a member of the firm of Todd & Dillon, which later became Todd, Dillon & Sullivan. He later practiced with Sullivan & Dubin. At the time of his death, he was a partner in the firm of Baskin & Sears.

Mr. Sullivan who lived in Bethesda, was a member of the Motor Carriers Lawyers Association and the ICC Practitioners. In private life, he was a member of the Bethesda Country Club, and a former member of its board. He was active in theater groups and was a member of the board of the Rockville Little Theater.

Survivors include his wife, Mary, of Bethesda; five sons, Justin of Kensington, William of McLean and Jerome, Roger and Francis, all of Bethesda; three daughters, Mary Elizabeth of Gaithersburg, Regina of Springfield and Helen of Bethesda, and three brothers, Roger, John and Richard, all of New Hampshire.