Bert Schneider, 78, a producer of Easy Rider and other films that helped define the social unrest of the late 1960s and early '70s, died Monday in Los Angeles.

Mr. Schneider was a major behind-the-scenes force in the movement to make Hollywood more responsive to a youthful audience.

Hearts and Minds (1974), which he produced with Peter Davis, was a documentary that focused on opposition to the Vietnam War. It won the Academy Award as best documentary in 1975.

He was executive producer of Easy Rider (1969), the biker film starring Peter Fonda and Dennis Hopper that captured the attitudes of a young generation. His next film was Bob Rafelson's Five Easy Pieces (1970), a dark family drama starring Jack Nicholson. He was also a producer of The Last Picture Show (1971), Peter Bogdanovich's award-winning reverie on small-town Texas life in the 1950s, and Days of Heaven (1978), Terrence Malick's turn-of-the-century drama. His last film was Broken English (1981), an unreleased picture.

In the 1960s, he and Rafelson created the TV comedy The Monkees. It received a 1967 Emmy for best comedy. - N.Y. Times News Service