McLean Stevenson, who played the fumbling commanding officer and chief surgeon of TV's "M*A*S*H," has died, his agent said Friday. He was 66.

Stevenson died of a heart attack late Thursday at a hospital, agent Robert Malcolm said.Stevenson played Lt. Col. Henry Blake, the womanizing goof-off commanding officer of the 4077th Mobile Army Surgical Hospital, for the first three seasons of "M*A*S*H." The role won him a 1973 Golden Globe Award and a 1974 Emmy nomination.

In the series, Blake died when his plane was lost at sea as he returned to the United States.

"McLean Stevenson was one of the kindest, most sensitive people I've worked with or known," said Gary Burghoff, who played Blake's clerk, Radar O'Reilly. "My personal sense of loss is magnified a thousand times by what this kind, funny gentleman has meant to all those who knew him."

Born in Bloomington, Ill., Stevenson was the son of a cardiologist. He worked on the losing presidential campaign of his cousin and next-door neighbor, Adlai Stevenson.

He was 31 before he broke into acting after careers as a medical supplies salesman, insurance clerk, seaman and assistant director of athletics at Northwestern University, where he earned a theater arts degree.

"I had nine jobs in eight years and I didn't like any of them," he told The Associated Press in 1975. He was walking across a football field when he decided to go into show business.

"I watched those poor slobs practicing like crazy, knowing that if they didn't block they wouldn't get paid," he recalled. "It was crazy to stay in college athletics unless you were a coach. I decided to go to New York and become an actor."

Stevenson is survived by his wife, Ginny; daughter Lindsey; son Jeffrey MacGregor; and sister, Ann Whitney.