He was taken off life support Thursday at the Desert Regional Medical Center, where his condition had been deteriorating over recent weeks.
The film-maker directed movies for more than four decades, including the acclaimed "Midnight Cowboy."
He suffered a stroke in December 2000. Two years earlier, he underwent quadruple heart bypass surgery.
"Marathon Man," with Laurence Olivier and Dustin Hoffman, has become known as one of Schlesinger's most gripping works.
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