Leonard J. Stone, 60, manager of international projects in the Washington office of the International Telephone and Telegraph Corp., died Tuesday at Georgetown University Hospital after a stroke.

He joined the ITT in 1959 as government relations engineer for the Communications Systems Division, an ITT subsidiary in Chicago. He joined the Washington office of the corporation in 1964.

Mr. Stone was born and reared in Chicago. He earned an electrical engineering degree from the Illinois Institute of Technology. He served with the Army Signal Corps in World War II, seeing duty in North Africa. After the war, he held several positions with the American Telephone and Telegraph Corp. in Chicago before joining ITT.

He was a member of the Institute of Electrical and Electronic Engineers, the National U.S.-China Trade Council, the Armed Forces Communications and Electronics Association, the Electronic Industries Association and the Aerospace Industries Association.

A resident of Silver Spring, Mr. Stone was an active member of St. John the Baptist Catholic Church there and was president of the St. Vincent de Paul Society of the church. He was a Past Grand Knight of the Holy Family Council of the Knights of Columbus and a Past Faithful Navigator of the Cardinal O'Boyle Assembly here. He belonged to the Potomac Chrysanthemum Society.

He is survived by his wife, Dorothy of Silver Spring; four sons, Dennis, of Frederick, Md., Leslie, of Westmont, N.J., Duane, of Brookville, and Dean, of Silver Spring; a daughter, Laure of Silver Spring, and one grandchild.