Edgar Bergen, 75, the celebrated entertainer and master ventriloquist who won worldwide fame through the wit and wisecracks of his wooden dummy, Charlie McCarthy, died in his sleep yesterday in Las Vegas.

The voice-throwing Mr. Bergen, who moved from vaudeville to become one of the great stars of the golden age of radio, opened Wednesday at Caesar's Palace Hotel for a two-week engagement that was to be part of his farewell to show business.

It was only 10 days ago that he had announced that he was retiring after 56 years in show business and sending his monocled, top-hatted partner to the Smithsonian Institution.

Mr. Bergen, who had earned college expenses in the 1920s by doing a magic and ventriloquism act at parties, was still finding audiences appreciative more than a half-century later.

"He was doing great," said a spokesman for Caesar's Palace," . . . standing ovations at every show." According to the spokesman, Mr. Bergen's body was found about 4 p.m. The cause of death was not determined.

In the days before television, when radio was the nation's chief home entertainment medium, Mr. Bergen for more than two years was recognized by the popularity polls as the No. 1 radio performer.

"The Chase & Sanborn Hour" in which he starred with McCarthy and his other dummy, Mortimer Snerd, the amiable bumpkin, began on May 9, 1937, and within a year had prevailed against such competition as "The Jack Benny Program," and "The Eddie Cantor Show."

The popularity of the Bergen show among a vast audience that could see none of the performers was clearly due less to the visual illusions provided by ventriloquism than to Mr. Bergen's gifts as a comic actor and creator of comic lines, situations and characters.

The Northwestern University-educated Mr. Bergen, projecting an air of calm intelligence; the brash McCarthy, with his street-urchin sauciness; and the slow-witted Snerd, with his air of rural ingenuousness, were each amusing in themselves and meshed brilliantly when heard together.

With a head reportedly costing $35 when made in the 1920s, and a body made by Mr. Bergen, Charlie McCarthy was the apparent speaker of many of the comedy act's most famous lines. The dummy went on to win a Master of Innuendo degree from his owner's alma mater.

The on-air target of many of his creation's sharpest barbs, Mr. Bergen sometimes expostulated: "I've taken a lot from you!"

To which the irrepressible McCarthy would shoot back: "Yes, and you've kept every penny of it."

If the wisecrack was a particularly American contribution to the art of comedy, Mr. Bergen, through his actually silent but seemingly glib associate was a major influence on the genre. The radio show on which it was exploited to such advantage remained a national institution until the advent of television.

In recent years, although he left semiretirement to make personal appearances at benefits and special events, Mr. Bergen may have been best known as the father of actress Candice Bergen.

Mr. Bergen was born Feb. 16, 1903, in Chicago, where his parents, John and Nellie Swanson Bergen, operated a retail dairy business for a time.

After discovering the rudiments of ventriloquism by himself as a boy, he spent 25 cents for "Herrmann's Wizzard's Manual," a work that provided instruction in the ancient art.

At 15 he managed to impress a touring vaudeville performer enough to get three months of free personal lessons in ventriloquism.

The first Charlie McCarthy, said to have been inspired by a picture of a self-assured Irish newsboy in a textbook, made his appearance while Mr. Bergen was in high school and helped him pass a history course taught by a woman unimpressed by his academic abilities.

"She said the world needs laughter more than another history teacher," Mr. Bergen recalled.

By 1922, Mr. Bergen began on the Chautauqua circuit as a magician and vaudeville, where his and McCarthy's ventriloquist. By 1926, he had entered popularity grew steadily, and they moved from the small towns to big cities and increasing fame.

With the impertinent McCarthy spewing insults at the bemused, benign Mr. Bergen, the pair toured widely, reaping acclaim in theaters and nightclubs around the world.

After impressing guests at a New York party given by hostess Elsa Maxwell, Mr. Bergen won a chance to appear on Rudy Vallee's radio show on Dec. 16, 1936. The next year he had his own show.

Mr. Bergen also made many short films and several feature length production and won a special Oscar in 1938.

As a comedian his gifts seemed beyond challenge. As a ventriloquist he was sometimes accused of the illusion-destroying sin of moving his lips.

He did not deny it. "I played on radio for so many years," he explained, "and it was ridiculous to sacrifice diction for 13 million people when there were only 300 watching in the audience."

As with so many show business teams, the true nature of the relationship between Mr. Bergen and his partner of decades could not always be easily inferred.

"To me it's quite remarkable that this carved piece of wood . . . should be so important," Mr. Bergen said once. ". . . It's ridiculous, even, that my appearing any place without Charlie is a complete failure. I do think it's a case of the tail wags the dog."

Indeed, to many of the millions in the radio audience, the salty, brassy, woman-chasing Charlie seemed less a wooden dummy than a living personality, and it was one of Mr. Bergen's great skills that he kept that illusion alive.

Even in his retirement press conference, Mr. Bergen continued to turn against himself the sharp tongue of his smart-aleck creation.

"How can you retire," McCarthy asked Bergen, "when you haven't worked since you met me?"

When asked why he planned to retire, Mr. Bergen said: "because I'm tired of earning money saving it and sharing it with people who didn't save it." He also said he was retiring to spend more time with his wife Frances at their Palm Springs, Calif., home.

Mr. Bergen was the author of the article on ventriloquism that appeared in many editions of the Encyclopedia Brittanica.

In addition to his wife, a former model, whom he married in 1945, and their daughter, Mr. Bergen is survived by a teen-aged son.