SPRINGFIELD, Mo. - Anthony Salerno, the scowling, cigar-chomping character whom Fortune magazine once rated the nation's top Mafia boss, has died from a stroke in federal prison, authorities said yesterday. He was 80.

Mr. Salerno, reputed ex-boss of the New York-based Genovese crime family, suffered a stroke about a week ago and died Monday at the U.S. Medical Center for Federal Prisoners, said Charlie Peterson, executive assistant to the warden.

Mr. Salerno, nicknamed "Fat Tony," had many health problems, including diabetes, a history of strokes and suspected prostate cancer, Peterson said. He had been in the Springfield medical center since May 1989.

He was serving two long racketeering sentences. In 1986 he was sentenced to 100 years for his role on the New York Mafia's ruling commission, and in 1988 he was sentenced to 70 years in connection with an organized crime bid-rigging scheme that affected virtually every high-rise building in Manhattan that used more than $2 million worth of concrete.

The latter conviction was overturned on appeal, but in June the Supreme Court reversed the lower court's ruling.

For years, investigators said, Mr. Salerno presided over a multimillion-dollar gambling and loan shark operation.

He was convicted on gambling and tax evasion charges in 1978, but his lawyer, Roy Cohn, said Mr. Salerno was not a gangster, merely a "sports gambler."

Mr. Salerno rose steadily in the Genovese hierarchy, becoming boss sometime in the early 1980s following the retirement of Philip Lombardo.

He supervised an organized crime network that stretched across the Northeast and used his control of several powerful Teamsters union locals to influence the election of several international presidents, including Jackie Presser and Roy Williams.

In the mid-1980s the FBI planted an electronic listening device in Mr. Salerno's social club and captured conversations in which Mr. Salerno met other mobsters.

Evidence gathered for the commission trial showed Salerno even benefited from hot dogs sold at the Bronx Zoo with a "mob tax" of 1 cent added to the cost of each frankfurter.