When Larry Bonds steps into the ring at Carrier Dome in Syracuse Saturday night, he faces not only the world welterweight champion but also the sole stockholder of a budding conglomerate called Sugar Ray Leonard Inc.

After 29 fights in less than five years, Ray Charles Leonard, 24, has earned $21 million in the ring -- $9.7 million from his fight last June against Roberto Duran in Montreal. After the Syracuse fight -- a modest challenge for Leonard to satisfy the World Boxing Council rule that he defend his title at least three times a year -- Leonard probably will be richer by about $1 million.

"If he quit now, he could live well for the rest of his life and never touch the principal," said Michael Trainer, the 40-year-old Silver Spring attorney who is Leonard's trusted business adviser.

From the beginning, the plan has been to make Leonard financially independent and his own boss. Leonard himself says he demanded that before he agreed to become a professional.

"I started out with my mind made up not to be owned by anyone," he said. "If a fighter offers a percentage, before long he has nothing for himself."

Leonard says he can remember feeling this way even at 19, when, fresh from his Olympic triumph, he was introduced to Trainer. A mutual friend friend, Janks Morton, an insurance man who worked with Leonard and other youngsters, brought Leonard up the stairs to Trainer's Silver Spring law office to seek advice.

The result of that first meeting was the formation of SRL Inc., a shell of a company started with $21,000 from local friends and acquaintances. When Leonard earned $40,000 for his first fight in June 1976 at Baltimore's Civic Center (a record purse for a pro debut the investors were repaid and Leonard owned the company.

Since then, the tightly knit Leonard-Morton-Trainer troika was followed a carefully laid out career plan. They have scheduled matches that presented maximum returns at minimum financial risks, while parlaying victories and Leonard's natural charisma to enhance his ring winnings and to prepare him for life after boxing.

A Silver Spring real estate firm oversees his real estate holdings in Montgomery and Prince George's counties. Merrill Lynch Pierce Fenner & Smith Inc. handles his extremely conservative investment portfolio. Leonard retains Arthur Young & Co., the international accounting firm, whose Washington office monitors his financial affairs to hold the Internal Revenue Service at bay. When Trainer goes to negotiate a deal or a fight on Leonard's behalf, the local Arthur Young office is available to advise him on tax and investment matters. a

Leonard has lent his name to a number of other commercial sponsors. They will pay him upwards of $1 million over the next two years.

Leonard and his 6-year-old son Ray Jr. are pushing 7-Up in commercials and advertisements. Leonard also has signed up with Franklin Sports Industries Inc. of Stoughton Mass., to promote a new line of boxing equipment.

He is under contract to Home Box Office the pay-TV subsidiary of Time Inc., to provide commentary on boxing broadcasts. His delivery is being honed by Marty Glickman, the once famous voice of the New York (football) Giants.

Leonard has signed with MCA, the giant entertainment company, to be on a weekly boxing show during the 1982 season. Called "Sugar Ray Leonard's Golden Gloves," the 26-week show will feature fights among state amateur boxing teams with Leonard providing his name and expert commentary.

Leonard is on call when sponsors want to use him as a kind of marketing tool. He knows this, and is proud of it. "If you look back, boxers were never considered marketable commodities," said Leonard, who repeatedly uses "marketable" when referring to himself.

Recently, for example, MCA summoned Leonard to a convention of television broadcasting executives at the New York Hilton. Leonard, who is a natural salesman with an easy manner and a quick smile, went to work graciously posing for pictures and signing autographs for a steady stream of admirers. MCA executives, meanwhile, were peddling the Golden Gloves show to TV officials from major television markets. It apparently was an effective one-two marketing punch, as one executive happily crowed, "Washington, New York, Chicago and Baltimore are locked up."

Larry Franklin, executive vice president of Franklin Sports Industries, describes the growth of his company's new boxing line pegged to Leonard as "phenomenal." After Leonard made an unannounced appearance at a recent sales meeting, said Franklin, "our salesmen got so pumped up, there was no way they wouldn't be successful."

The income flowing from Leonard's varied holdings is described and analyzed in a monthly computer printout. This keeps the youthful captialist informed of his growing net worth. "My fear was that something would happen to me," said Trainer. "Now, Ray can go to the books himself and check every dime."

As sole stockholder in SRL Inc., Leonard pays himself an annual salary and bonuses in the "six figures," said Trainer. Pension, disability and benefit plans also have been established to take care of Leonard's family.

Morton, who now works full time for Leonard, and Trainer, who now devotes 80 percent of his time to his most famous client, also are paid by SRL Inc.

Trainer, apparently mindful of the financial fate of so many fighters, bristles when questioned about his financial interest in Leonard.

"Let's look back," said Trainer. "The first year, I didn't make a nickel. He made several hundred thousand. The second year I took a reduced hourly rate. I didn't like charging him anything, but it was taking time from my business. Starting in 1980, I got paid by the event.

"He pays me what he thinks I'm worth," said Trainer. "Me talking to him about money is like talking to my young son about it."

SRL Inc. is structured so that Leonard, who could be taxed at a rate of 70 percent a year, pays taxes on a 50 percent rate. This is not just another tax dodge, however.

"Mike (Trainer) instructed me that Leonard is never to be embarrassed by any position we might take on his tax returns, because that information has a way of getting out to the public," said John Hamm, the Arthur Young executive who handles SRL Inc. Added Hamm: "I've never been involved with a client so protected."

Indeed, there is a feeling of "us and them" in the Leonard circle, with the fighter carefully protected from those outside whose motives are automatically suspected. Even one of Leonard's business sponsors felt locked out.

"Even though I'm helping them and making money for them, I have the distinct feeling that I'm an outsider," he said. He found Morton, a publicity-shy man in his early 40s, "suspicious and untrusting" of him.

"There's a loyalty and trust," said Leonard."We believe in each other. It's like a family."

"Control" is a word often repeated by Trainer in referring to marketing Leonard.

For example, after the Duran fight in Montreal, said Trainer, NBC's Bryant Gumbel turned up for an exclusive interview. But Trainer steered Leonard away from NBC, saving him for an appearance the next day on Good Morning, America. The reason: ABC laid out $2 million to replay the fight.

As for promoters, if they want to use the Leonard name they must first pass Trainer's stringent taste test, then pay dearly for the privilege. The long list of rejections include numerous proposals by oil and gas tax shelters. lThe cable television firms vying for the franchise in Prince George's County offered him stock to use his name. Politicians wanted his endorsement, Montgomery County wanted to publicize that he invested in its bonds, and even a local bank wanted to put him on the board of directors if he bought some of its stock.

"With a guy like him, you have to be very careful about who uses his name," Trainer said. "You have to be a policeman."

He says that the toughest lesson they had to teach Leonard was that people wanted to use him. "He's more cynical now. He knows when you come up to him, you're only talking to him because of who he is."