A lawyer who once represented Teamsters president Jimmy Hoffa said yesterday that Hoffa had him tell two Mafia bosses in early 1963 to have President John F. Kennedy killed.

Tampa lawyer Frank Ragano said on ABC's "Good Morning, America" that he "thought it was a joke" but later became convinced that it was serious. He told the New York Post, which first reported on Ragano's allegations Tuesday, that he was willing to repeat his story under oath to a congressional committee.

Ragano, who was close to the two Mafia bosses, Santos Trafficante of Tampa and Carlos Marcello of New Orleans, once ridiculed the idea that the two might have been involved in the assassination.

According to an April 11, 1967, FBI report, Ragano told agents in an interview that he had been driving through New Orleans with Marcello and Trafficante when the car radio blared out the latest item about District Attorney Jim Garrison's investigation of the Kennedy murder.

Ragano, who was in the back seat, said Trafficante listened for a moment, then turned to Marcello and stated: " 'Carlos, the next thing you know, they'll be blaming the president's assassination on us.' "

The House Assassinations Committee, after an inquiry in the late 1970s, concluded that Kennedy "was probably assassinated as the result of a conspiracy." The committee said that Marcello and Trafficante had "the motive, means and opportunity" to take part in the murder, but the panel said it had no direct evidence against them.

Ragano, 68, now writing his autobiography and appealing a three-year-sentence for income tax evasion, did not testify before the committee. He was Trafficante's lawyer as well as Hoffa's for many years, and was present with 13 top Mafia bosses from around the country, including Marcello and Trafficante, when they were arrested at a Queens, N.Y., restaurant in 1966 to discuss what police described as "matters of national importance" to organized crime.

Ragano could not be reached for direct comment yesterday, but he told the New York Post that he delivered Hoffa's message to Trafficante and Marcello at a meeting in the Royal Orleans Hotel in New Orleans a few days after meeting with Hoffa at Teamsters headquarters here. Trafficante has since died. Marcello is 81 and reportedly suffering from Alzheimer's disease.

According to the New York Post account, Ragano told them, "You won't believe what Hoffa wants me to tell you. Jimmy wants you to kill the president." Instead of laughing, Ragano said, Marcello and Trafficante "looked at each other in a way that made me uncomfortable. . . . It made me think they already had such a thought in their mind."

A few minutes after the Nov. 22, 1963, assassination, Ragano said Hoffa called him and asked: "Have you heard the good news? They killed the SOB." Ragano said he had dinner with Trafficante that same night and Trafficante offered a toast to Kennedy's death.

On ABC yesterday, Ragano said Hoffa, who was under indictment for jury tampering, wanted President Kennedy killed because of the "Get Hoffa" efforts of Attorney General Robert F. Kennedy. "If Bobby was killed," he said the president might simply have appointed someone who was "more vicious."

This is not the first time Ragano has sought to capitalize on his relationship with Hoffa. In 1982, he made efforts to produce a movie about "the life and death of Jimmy Hoffa," who was presumably murdered in 1975. Ragano sold percentages of the prospective profits to local investors. He was convicted for failing to report $107,000 of the money he took in on his 1982 and 1983 tax returns and sentenced last year to three years in prison. The movie was never made.

In a related development, former House Assassinations Committee chairman Louis Stokes (D-Ohio) said he is actively exploring the possibility of releasing all that is "releasable" from committee records put under a 50-year seal. He said he is disturbed by Oliver Stone's movie, "JFK," and its charges of government involvement in a conspiracy to kill Kennedy and to cover it up.