John Belushi, 33, a wildly energetic comic actor who captured a huge and admiring audience on television's "Saturday Night Live" and expanded his fame and following with the overwhelming vitality of his performance in the film "Animal House," died yesterday in Los Angeles.

The creator of a humor that was outrageous and iconoclastic, that provided a full measure of the amusement and diversion available in the uninhibited display of seemingly gargantuan drives and appetites, Belushi attained a vast popularity, particularly among teen-agers and his 20- and 30-year-old contemporaries.

The roly-poly performer, renowned for his expressive leer and his on-stage grunts, groans and gruffness, was found in the bedroom of a bungalow he was renting at a Sunset Strip hotel while in Hollywood to make a movie.

Although a hotel employe was quoted as saying Belushi appeared to have choked on food, officials of the Los Angeles Police Department and the coroner's office declined to speculate on a cause of death and said it could not be determined until an autopsy had been performed.

According to police, Belushi was found shortly after noon, Los Angeles time, by an associate who became concerned when he could not reach the comedian by telephone. The associate, identified as William Wallace, the pudgy actor's physical trainer, reportedly tried to administer mouth-to-mouth resuscitation.

The hotel employe, identified as a gardener and security guard, told the Associated Press that he also tried to revive the comedian, who was lying on a bed with his head on a pillow.

Fire department paramedics were called at 12:36 p.m. to the hotel, the Chateau Marmont. They pronounced Belushi dead there.

Police said they had no reason to suspect foul play.

During the years of his fame, which began in the middle 1970s, discussion and imitation of Belushi's roles and routines became conversational staples in broad segments of American society.

Audiences delighted in his grotesquely comic depictions of a Samurai warrior in incongruous circumstances, of a member of the "Killer Bees" and as a television commentator given to emotional digressions and violent outbursts.

One of his most memorable roles on NBC-TV's "Saturday Night Live" was as the owner of an ethnic luncheonette where the language barrier translated the most complex and detailed order into "Cheeseburger, cheeseburger."

The stardom achieved on television made the difficult transition to the motion picture screen. There, Belushi created Bluto Blutarsky, a campus character whose unexampled grossness and inexhaustible prankishness pushed the actor's popularity to new heights in the 1978 comedy hit, "Animal House."

Belushi, who also appeared in several other films, was born Jan. 24, 1949, in Chicago, one of four children of a couple of Albanian extraction.

Although he was reticent about his private life, he told an interviewer once that his parents regarded him as "the special one" in the family.

As a boy growing up in the Chicago suburb of Wheaton, he was said to have been incorrigibly disruptive in grade school. In high school, however, he was described as an obsessive, highly disciplined achiever, who captained his high school football team as a linebacker, played other sports, performed in school shows and in the year of his graduation in 1967, was named Homecoming King.

After high school came a season of summer stock, then attendance at several colleges in the Midwest. By 1969, he had lost his enthusiasm for plays and teamed up with friends to live in Chicago and convert a faltering coffeehouse into a kind of antiestablishment cabaret.

The cabaret's demise led to a job with Second City, a Chicago-based improvisational troupe, which in turn led him to another job, in New York, as a performer in a show staged by the National Lampoon.

After winning favorable notices in Lampoon shows, he was asked in 1975 to audition for the first season of "Saturday Night," where he achieved fame and fortune by, in the words of one reviewer, "being what all good comics are--a bit insane, always unpredictable." He left the show in 1979.

In addition to his comedy efforts, he and Dan Aykroyd collaborated on a soul-singing act, which was first used to warm up "Saturday Night" audiences, then was incorporated into the show, and finally was made into a film, "The Blues Brothers." Belushi and Aykroyd also sang on stage, and cut an album that sold more than 2.5 million copies.

Belushi's latest movie was "Neighbors." His others included "1941" and "Continental Divide" in which he essayed a role as a romantic hero, to a mixed reception.

He received an Emmy for comedy-writing for "Saturday Night Live."

Belushi and his wife, Judy, a book designer, had homes in New York's Greenwich Village and on Martha's Vineyard.

Belushi's survivors also include two brothers, Jimmy and Billy, and his parents, Adam and Agnes.