A Washington man was convicted on federal fraud charges yesterday for concocting an elaborate scheme in which he took more than $200,000 from 13 people -- most of them recent immigrants -- after promising to establish them in businesses that he never created.

After deliberating for seven hours, a jury in U.S. District Court in Alexandria found Gary Stephen Simon, 31, guilty of nine counts of mail fraud, seven counts of interstate transportation of stolen property, and two counts of tax fraud. He was acquitted of two obstruction of justice charges.

"What this man showed his poor innocent victims was a Hollywood set," said Assistant U.S. Attorney Lawrence J. Leiser in final arguments. "And behind that set there was nothing but lies."

District Judge James C. Cacheris revoked Simon's bond and ordered him held in jail pending sentencing June 21. He could receive a maximum of 123 years in prison, according to prosecutors.

In a seven-day trial with 50 witnesses, the government portrayed Simon as a man who preyed on unsophisticated but eager businessmen, crushing their dreams of building small "mom and pop" stores by taking their life savings and giving them nothing in return.

Mark D. Cummings, one of Simon's attorneys, said that his client was guilty only of bad judgment and referred to the 21-count indictment as a "trumped up scam."

"It came too fast for this young man to handle," Cummings said in his closing arguments. "He was in over his head. He's a little immature, but that's not a crime." Cummings said he would probably appeal the verdict.

Prosecutors said that Simon would approach people, offering to turn over completely prepared retail establishments, such as a carry-out restaurant, a wine and cheese shop or a clothing store, for a fee.

"Gary Simon preyed mostly on foreigners because they didn't understand the complexities of leasing and construction," special assistant U.S. attorney Michael H. Simon said in court. "Gary Simon looked out only for the best interests of Gary Simon."

Chang Choi, a Korean who had worked seven years blasting tunnels for the Washington Metro construction and saved more than $35,000, testified that he turned over about $30,000 to Gary Simon so that he could build a carry-out restaurant for him in the District. Choi said he lost his money.

The indictments followed a lengthy investigation by U.S. postal inspectors. In court, Simon acknowledged using several aliases. Between 1979 and 1982 he claimed to be the chief executive officer, vice president and general counsel of Commercial Development and Finance Corp., he said.

Leiser said that Simon tried to create an image of that company as a large corporation with millions of dollars in assets and offices throughout the country.

The government charged that between December 1979 and July 1981 Simon was given $213,598 by 13 people for businesses, and not one was delivered.

Simon took the stand in his own defense against the advice of his lawyers.

"I built an ice-cream parlor in Silver Spring, and when I say I built it I mean I built it with a hammer and nails from nothing," he said.

He added that he had made mistakes and been hasty in judgment, but that he had already paid dearly for his errors. When asked whether he had devised a scheme deliberately to steal money from his customers, he stared glumly at the jury and replied: "Absolutely not."

But the government lawyers characterized his testimony as deceitful, and constantly reminded the jurors of the suffering that Simon's victims had gone through.

"There were so many innocent people who have been hurt badly by what he has done," said special assistant U.S. attorney Simon. "I don't see how he can go unpunished."