William C. Sankey, 76, a retired salesman for the Lindsay Cadillac Company of Alexandria, died Sunday at Jefferson Memorial Hospital of cardiac arrest.

A resident of Alexandria, Mr. Sankey retired from Lindsay Cadillac in January after 14 years with the company. Before that he had been sales manager of Williams and Baker Rambler.

Born in New Castle, Pa., Mr. Sankey joined the Army Quartermaster Corps in 1941, serving also in the Office of Stretegic Services.

When he left the Army, Mr. Sankey joined the War Assets Administration as a special assistant and assistant deputy administrator of the field services division. He left government service in 1948 to join Williams and Baker.

Mr. Sankey was a member of the Zembo Temple of Harrisburg, Pa., and a life member of the Ancient Accepted Scottish Rite in New Castle. He was also an honorary member of the Lodge of Craft No. 433, F & AM, in New Castle, receiving his 50-year Masonic service emblem in 1975, and of Kena Temple in Alexandria. He was past grand secretary of Masonic bodies in Harrisburg, Council of Deliberation AASR, Harrisburg.

In addition, Mr. Sankey belonged to the National City Christian Church in Washington, Belle Haven Country Club in Alexandria and the Mount Vernon Kiwanis Club, of which he was president in 1971.

Survivors include his wife, Dorothy L., and son, Curtin P., both of the home; a sister, Edith S. Dilley, of Homestead, Fla., a grandson and a great-grandson.