PROVIDENCE, R.I. – Mayor Vincent “Buddy” Cianci Jr. was convicted Monday of turning City Hall into a den of thieves at the same time the popular and irrepressible politician was overseeing a renaissance in Rhode Island’s biggest city.

Cianci, 61, was found guilty of racketeering conspiracy as the jury concluded that he and two co-defendants participated in a scheme to solicit bribes in exchange for city jobs, contracts and tax breaks. But he was acquitted of racketeering and 10 other federal counts.

The mayor could get up to 20 years in prison and a $250,000 fine. No sentencing date was set. The state attorney general issued an opinion after the verdict, saying Cianci can remain in office until he is sentenced.

Cianci has said he plans to run for a fourth consecutive term this fall, and aides said he can remain in office until his appeals are exhausted.

The mayor was stone-faced upon hearing the guilty verdict but allowed himself a slight smile when the last of the acquittals was announced. He said only, “I feel fine” as he left the courtroom. He remained free on $50,000 bail and was picked up by his black limousine outside the courthouse and whisked back to City Hall.

There was a smattering of applause from a crowd outside the courthouse as prosecutors left, but two people also yelled: “Let him go!”

Cianci, a stocky bachelor with a thatch-like toupee and a gift for gab, remained highly visible throughout his trial, and the indictment seemed to do little to hurt his popularity. He is credited with rejuvenating Providence with new parks, a $460 million shopping mall and more than $300 million in transportation improvements.

Prosecutors would not comment on the verdict, citing a judge’s gag order that remains in effect until the separate trial of Cianci’s chief of staff is over.

The case was the biggest trial to come out of Operation Plunder Dome, the FBI’s five-year investigation of City Hall graft.

During the seven-week trial, prosecutors said Cianci, his former top aide and two businessmen turned Providence into a “city for sale,” where just about anything could be bought for the right price.

Cianci’s co-defendants – former top aide Frank Corrente and tow-truck operator Richard Autiello – were convicted of racketeering conspiracy. A fourth defendant charged with racketeering, businessman Edward Voccola, was acquitted midway through the trial by the judge.

Under federal law, participants in a racketeering conspiracy are responsible for the acts of other conspirators.

Prosecutors presented a colorful array of witnesses who testified that city officials routinely shook them down.

A woman testified that said she paid $5,000 to get her son a job on the police force, and a man said he paid a $5,000 bribe for a $9-an-hour temporary city job.

Convicted felons boasted in surveillance tapes about their City Hall connections, and salty tow-truck operators testified they set up straw donors to illegally contribute to Cianci’s campaign fund.

Defense attorneys said the contributions were voluntary or bribes solicited by others. They called Cianci’s accusers bums, liars and thieves who traded on Cianci’s name, and said one witness was “a pig, plain and simple.”

The government’s star witness was businessman Antonio Freitas, who secretly recorded about 180 conversations with city officials in 1998 and 1999, and paid bribes for tax breaks and other deals at the FBI’s direction.

One of the most celebrated witnesses never took the stand: former tax board Chairman Joseph Pannone, who pleaded guilty to corruption.

On the tapes, Pannone told Freitas that the mayor gave him advice on how to take bribes. He also described Cianci as a man addicted to money.

“He needs the green. He’s got to fix his hair,” Pannone said.

On another tape, Pannone told Freitas: “That’s how the city of Providence is run. If you don’t pay, forget it. … This has been going on since day one.”