James Ramsay Hunt Jr., 70, a retired deputy chief of the counterintelligence staff of the Central Intelligence Agency, died of cancer Saturday at Doctor's Hospital in Sarasota, Fla.

Mr. Hunt was born in New York City and educated at St. Paul's School and Yale University, where he graduated in 1933. He was a banker in Boston and New York until World War II, when he was commissioned in the Navy.

He began his career in intelligence in the Office of Naval Intelligence.He later served on the staff of Adm. William Halsey, commander of the 7th Fleet, in the Pacific. He left the service with the rank of lieutenant commander.

In 1946, Mr. Hunt became chief of the New York Contact Branch, a part of the Central Intelligence Group, a predecessor to the CIA. He was transferred to CIA headquarters in Washington in 1951 as a special assistant for clandestine activities.

In 1954, he was assigned to Paris and was the CIA's senior representative there until 1959, when he returned to Washington. He was deputy chief of operations and then deputy chief of the counterintelligence staff, a post he held for 10 years until his retirement in 1969.

Mr. Hunt lived in Washington until 1972. Since then, he had spent part of each year in Katonah, N.Y., and in Sarasota, Fla.

He was a member of the Century Club in New York, the Adirondack League Club, the Bedford Golf and Tennis Club and the Tobique Salmon Club.

His wife, Eleanor Pratt Hunt, died last July.

Survivors include three daughters, Barbara Hunt Tanham, of Middleburg, Va., Eleanor Hunt Bolger, of Missoula, Mont., and Lisa Hunt Bon, of Ottawa, Canada; two sons, W. Barnes, of New York City and David P., of Washington; a sister, Alice Hunt Sokoloff, of Lakeland, Fla., and 11 grandchildren. Another son, James Ramsay Hunt III, died in 1955.