SANTA MARIA, Calif. (AP) _ Movie producer John Derek, husband of actress Bo Derek, was in extremely critical condition today following heart surgery.

Derek, 71, underwent lengthy surgery early Thursday at Marian Medical Center, a day after he was found unconscious in his Santa Ynez Valley home. A nursing supervisor confirmed his condition this morning.

Dr. Luke Faber, the cardiac surgeon, described Derek's condition as a spontaneous catastrophic injury to the heart and aorta, which carries blood to the arteries for distribution throughout the body.

Mrs. Derek, star of the film ``10,'' was at his bedside.

Derek, an actor-turned-producer, suffered a mild heart attack in 1986.

He appeared in such films as ``Knock on Any Door,'' ``All the King's Men'' and ``Exodus.'' His productions have included ``Tarzan the Ape Man,'' which starred his wife.