Irvin Feld, 66, the son of East European immigrants who grew up to be a major American impresario and an heir in spirit to the legendary P.T. Barnum as the owner and operator of the Ringling Bros. and Barnum & Bailey Circus, died yesterday in a Venice, Fla., hospital.

Mr. Feld, who was born in Hagerstown and lived in Potomac, died of a cerebral hemorrhage while in Florida to attend this year's opening of one of the many innovations he introduced to his storied circus -- a "clown college" for the training of new performers.

Over the years, in addition to running Ringling Bros., Mr. Feld was also a show-business entrepreneur who built a chain of record stores, promoted rock groups, produced concerts involving some of the biggest names in popular music and for a generation booked entertainment at the Carter Barron Amphitheater here.

Although never a circus performer himself, Mr. Feld told of falling in love with the Big Top as a child, and as a teen-ager in the 1930s he worked at what could be viewed as an allied occupation -- selling snake-oil from a card table at carnivals.

In the Depression summer of 1934, after his clothing-merchant father suffered reverses, the $3,000 he and his brother, Israel, now deceased, made as pitchmen throughout Maryland and Pennsylvania saved the family, which included four sisters. Bigger sums were in store. In 1967 he bought the circus -- The Greatest Show on Earth -- for $8 million.

Four years later, after streamlining and revitalizing the venerable American institution, Mr. Feld sold it to Mattel Inc. for an estimated $50 million in stock. He was retained as president, producer and chief executive officer.

Two years ago, with fanfare and hoopla reminiscent of nothing less than a full-fledged, three-ring circus, Mr. Feld bought back the Ringling empire, which by then included not only two circus companies, but also an elaborate Las Vegas magic show and traveling ice shows that featured Walt Disney characters on skates.

He paid $22.8 million for the holdings, which included 500 animals, two circus trains and all the grease paint, tanbark and sequined costumes needed to keep his shows on the road and outfit 1,200 clowns, daredevils, skaters, elephant tenders and members of associated professions.

"The good Lord never meant for a circus to be owned by a corporation," said Mr. Feld in announcing the purchase as a band blared, balloons soared and a ponderous pachyderm looked on thoughtfully.

With many stops along the way, the path that led Mr. Feld to recognition as one of the world's principal impresarios of traveling shows has been traced to his boyhood exploits as a snake-oil salesman.

After high school, he became a full-time salesman for the firm that had supplied him with his original nostrum. By 1938, he had so impressed his superiors that they advanced money to help him and his brother open a drugstore on Seventh Street NW.

Records proved big-sellers at the store. Mr. Feld gained confidence in his ability to tell which would sell and which would not. Soon he had opened Super Music City record stores, and not long afterward, he branched out into producing both his own records and his own live concerts.

Credited with anticipating the rock and roll mania, Mr. Feld began in the 1950s to book such performers -- then relatively unknown but soon to become explosively famous -- as Chubby Checker, Bill Haley and the Comets, Fats Domino and the Everly Brothers. By the 1960s, he was arranging personal appearances for such names as Frank Sinatra, Nat King Cole and Harry Belafonte.

Meanwhile, again in the 1950s, he recognized the significance of the national trend toward construction of big indoor arenas. At the same time, he noted the declining fortunes of the Ringling circus, descendant of the show started by Barnum in 1871.

When he persuaded then-owner John Ringling North to turn over management of the show to him in 1956, Mr. Feld moved quickly to fold the circus' costly and labor-intensive tent shows and to book the production into indoor arenas. But the fiscal drain continued. Finally in 1967, Mr. Feld, with his brother and another partner, bought the circus.

Declaring the event "the happiest moment of my life," he moved quickly to strip away what was seen as an aura of tawdriness and decay. Working from a corporate base in Washington, he eliminated so-called freak shows, added new, young acrobats, started his clown school, scoured Europe for new acts and set up two units -- designated "red" and "blue" -- each of which offered a different show.

As one of the innovations that has the Barnum legacy alive and flourishing, each toured, appearing in a given city in alternate years, then returning to base for refitting, so that the same show never played the same city twice.

"I would like to be remembered for having made a contribution to the continuance of the circus," Mr. Feld once said. "It's practically all we have left of good, wholesome, clean entertainment that the whole family can enjoy."

Survivors include a daughter, Karen, of Washington; a son, Kenneth, of Potomac; four sisters, Fannie Feld of Washington, Zelda Fribush of Locust Grove, Va., Doris Goldstein of Rockville, and Freda Arenson of Sarasota, Fla., and three granddaughters.