Until 1982, when Luciano Pavarotti sat for 4 1/2 hours signing more than 10,000 autographs here under a $300,000 tent, few people outside the "casino cities" -- Atlantic City, Las Vegas, Reno and the Bahamas -- had heard of the man who brought the renowned tenor to that place. But since then, life has changed for Tibor Rudas. And tonight, at the Baltimore Civic Center, in conjunction with Baltimore Opera's 35th anniversary, Rudas will present his 14th Pavarotti concert -- this one for nearly 14,000 people.

"I started something that will live forever," he said, nibbling fresh fruit salad in a hotel coffee shop and looking, with his groomed gray hair, elegantly lined face and slender body, surprisingly reminiscent of Alistair Cooke.

Now 59, the Hungarian-born Rudas has produced, according to his biography, "possibly every major act in the business today," including Frank Sinatra and Diana Ross, for nearly every major casino in the United States and the Bahamas.

But he began as a choirboy in Budapest, along the way learning a form of mid-European gymnastic dance, earning a degree in business administration and touring Switzerland to study casino entertainment. After World War II, he ended up in Australia, without a passport.

To earn a living, Rudas began to teach the dance.

"I had thousands of children . . . and I kept on promising them so much, . . . so I formed a group," he explained. That troupe, "The Fabulous Rudas Acro-Dancers," ended up in 1963 in Las Vegas by way of Calcutta and Europe. And Las Vegas is where Rudas has remained.

Oh, there were a few other accomplishments. He purchased a partial license to the title "Ziegfeld's Follies" from the Shubert Organization and brought Ziegfeld's widow, Billie Burke, to Australia. He turned Walt Disney's "Snow White" into a children's musical that ran in Australia and New Zealand for 18 years. He patented the "Living Screen," a technique used today by the Ice Capades that projects a skater's image on a screen then brings the performer literally through a slit in the screen onto the ice and back again.

But his return to classical music came in developing Superstar Theatre for Resorts International in Atlantic City.

"I got contacts," he said, "but eventually I ran out of names. Then I went on my hands and knees and pleaded for . . . Zubin Mehta to bring out the New York Philharmonic. It was an incredible success."

Convincing Pavarotti to perform in a casino-sponsored event took three years.

"He expected drunk players still pulling the machine," explained Rudas. But in 1982, Rudas and Pavarotti's agent, Herbert Breslin, convinced Pavarotti in a marathon negotiation in the middle of a La Scala performance of "Aida."

Breslin ran "during the interval" to talk to Pavarotti , who "wouldn't budge," said Rudas. "Finally," Rudas continued, "just before the last act . . . I came to an idea . . . to use a tent next to the casino . . . and before he Radames, Pavarotti's operatic character died, Luciano agreed. It was the funniest contact I ever had in my life.

"We became such friends overnight," remembered Rudas, "he was so overwhelmed."

That first concert's 3,000 seats sold out in 20 minutes. Five thousand more were added, and Rudas has since, with a few variations (including the sometime addition of soprano Dame Joan Sutherland), repeated the theme 13 times in such cities as Seattle, Cleveland and Louisville, mainly with local opera companies. According to the formula, everyone makes money. Opera companies, said Rudas, can make "more money on the one concert than they can in the whole season."

The Baltimore Opera, according to its general manager Jay Holbrook, tried for five years to engage Pavarotti independently. Holbrook, who had a two-year $700,000 operating deficit at the beginning of this season, said he was concerned about Rudas' casino affiliation briefly, but dismissed his concern after talking to other opera companies who "all worked with this mysterious man."

"I was assured by . . . my colleagues," said Holbrook, ". . . that his ecclesiasticism is only exceeded by the monumentality of his productions . . . that he is a bit of an eccentric . . . but that he is honest."

To those who have heard about or dealt with him, Tibor Rudas is a perfectionist. He is, according to Opera America Executive Director Martin Kagan, a "sort of rock producer," with a "Barnum and Bailey thing" that is "very positive" for opera.

"It was the most successful PR event we'd ever done," said Louisville (Kentucky) Opera General Director Thompson Smiley of his January 1986 event with Pavarotti. "Tibor," he continued, is "a buccaneer . . . who drives a hard bargain, but then again, I'm a Scotsman."

Even though Rudas "guarantees" opera companies will make money, (based on his track record) he is secretive to outsiders about the details. Holbrook outlined a few basics. Of the $500,000-$600,000 gross concert receipts expected tonight, the Baltimore Opera (with an annual budget of $1.3 million) expects to keep about $100,000, based on a complicated agreement that gives the company between 12 and 33 percent of receipts from 13,667 tickets priced from $20 to $250. Another part of the profit comes from the Baltimore Opera-organized buffet dinner/dance the top patrons ($375 per ticket, including the concert) will attend. Approximately 500 people will sip unlimited Chandon champagne, watch Pavarotti eat and get an autograph.

*"The bottom line," said Louisville's Smiley, "is that we have the names and addresses of 13,000 people . . . who behaved like wild basketball fans for opera . For Holbrook, "the public response has been tremendous," generating the sale of 10,000 seats from Nov. 1 to Dec. 31. As of Friday morning, only about 400 of the 13,667 seats remained.

Part of the secret, both agree, is the quality of the complete Rudas production. Rudas handles everything, including the rental of the hall (in Baltimore, $40,000), lights, sound ($60,000-$75,000 per concert), the union orchestra (about $20,000 for, in this case, the Delaware Symphony), and of course, Pavarotti's fee, which is the biggest secret of all. Rudas classified it as "six figures."

"I think that Pavarotti is the highest paid performer on earth today," he said. Pavarotti outsells Sinatra, who "will fill the same 15,000 seats with a top price of $50 at the most," Rudas noted.

He is especially proud of his sound system, developed by Decca recording technician Jimmy Lock. The system, according to Rudas, "spreads the voice, rather than enlarges it." Rudas also pays attention to details like humidifiers to protect the voice, and the distance Pavarotti must walk from the stage to the dressing room, between arias. Reducing that distance provides a "psychological boost," Rudas says, because Pavarotti hears applause in the dressing room "and is crazy to come out again."

Together, details like these seem to produce, according to Louisville's Smiley, a concert with "an evangelical side to it, almost like Billy Graham." Holbrook joked about keeping "the civic center from selling popcorn," remembering a Houston Pavarotti performance. "It's important," he continued, that Rudas "knows the difference between a Las Vegas crowd and an opera company crowd."

Though he knows that difference, Rudas is far from finished with Las Vegas style shows. Last week, he flew from Atlantic City to the Bahamas to oversee his casino show there (a magic show with 16 dancing girls who disappear on stage) before returning to Baltimore on Thursday. "I have a lot of innovations," he said, and "if there would be more idiots like myself, opera would be better off."