Justice Department prosecutors are considering whether to seek an indictment of Roy L. Williams, the expected new Teamsters Union president, for his part in the same alleged transaction, involving a trucking deregulation bill, for which they investigated but declined to prosecute Sen. Howard Cannon (D-Nev.).

Sources familiar with the investigation said a decision is expected in the next few weeks -- possibly before the Teamsters meet in Las Vegas June 1 to pick a successor to Frank Fitzsimmons, who died of cancer last week.

The timing is conincidental, the sources said, and one cautioned that no final assessment had been made. If the decision is to recommend an indictment, the request will go to a federal grand jury in Chicago, which has been investigating the alleged transaction for more than a year.

Williams' Washington lawyer, Thomas J. Wadden Jr., said he had no comment on the developments. The Teamsters official's Kansas City public relations man, Robert E. Brown, said Williams has been the victim of a government smear campaign and will not let any allegations prevent him from future service to the union.

"You didn't see Billie Jean King commit suicide [over had publicity], did you?" Brown said in a telephone interview Friday. "You have to continue to do the best you can, whoever's trying to persecute you."

Any indictment of Williams now could be an embarrassment to the Reagan administration because of its close connections with the nation's largest union. The Teamsters union was one of only two major unions to endorse Reagan, and the president visited the union's Washington headquarters soon after his inauguration. Reagan was criticized for naming Jackie Presser, a Teamsters vice president and one-time rival to Williams for the top job, to a transition advisory post.

Williams, 66, has long been a power in the Teamsters. He is an international vice president in Kansas City and was a longtime trustee of the much-investigated Teamsters Central States Pension Fund before resigning in 1977 as part of an agreement negotiated under pressure from the Labor Department.

The dissident Teamsters for a Democratic Union calculated, using Labor Department records, that Williams made $178,000 from his several Teamsters jobs in 1979.

Williams told a Senate subcommittee at oversight hearings on the Teamsters' pension fund last August that he was under investigation by several grand juries and had been the subject of extensive electronic surveillance. He also invoked his Fifth Amendment privilege against self-incrimination 23 times when asked about ties to alleged organized crime boss Nick Civella in Kansas City.

Williams has been indicted three times -- twice on embezzlement charges, in 1962 and 1972, and once on charges of making false entries in government reporting forms. He was found innocent in 1962, although six codefendants were convicted. He was acquitted of the 1972 charge, and the 1974 indictment was dismissed.

The grand jury in Chicago has been investigating the relationship between Williams and Allen Dorfman, an insurance man convicted of conspiring to defraud the Central States fund in 1972, and their alleged dealings with Cannon over a trucking deregulation bill. The grand jury was probing whether Cannon had agreed to derail the bill in return for a chance to bid on some union land in Las Vegas that he and his neighbors wanted to save from high-rise development. The investigation was called "Pendorf" by the FBI for "pension" and "Dorfman."

Sources said FBI wiretaps picked up a telephone conversation between Williams and Dorfman in which the two bragged that Cannon had delayed the deregulation bill. In public statements when the FBI's investigation became known, Cannon said he met with Dorfman and Teamsters officials in his Las Vegas office in January 1979 to discuss the land and an alternative form of deregulation. But he denied any impropriety.

Cannon made an offer on the land, but it was turned down. The deregulation bill was passed, and Justice Department officials dropped the Cannon investigation.

However, sources said the evidence against Williams and Dorfman is being reviewed by new officials in the Justice Department to see if an improper offer had been made to Cannon.

The union executive board is to meet next Saturday to name an interim president, who will serve until the Teamster convention next month in Las Vegas. Williams' chances of winning the top job are enhanced because he has the support of Presser.

Presser told a luncheon in Cleveland Friday, according to United Press International, that he was confident Williams would get Fitzsimmons' job. "I'm waiting my turn and it's down the road," he said. Presser added that legal questions about Williams "present no problem to me" in considering Williams' qualification for the presidency.

Presser's position on the Reagan transition team drew fire because an organized crime hit man, since turned government witness, had claimed in court documents and in legislative hearings that Presser took orders from Mafia bosses in Cleveland. Like Williams, Presser has denied any organized crime ties.

Sen. Sam Nunn (D-Ga.), ranking minority member of the Senate's permanent subcommittee on investigations, issued a statement late Friday saying Fitzsimmons' death offered the Teamsters a "golden opportunity" to reform their union. Although he didn't name Williams, he said the Teamster leadership had a "dedsplorable" record in managing the Central States Pension Fund and criticized union officials who refused to cooperate with his investigation.

Wadden, Williams' attorney, said Friday that the Senate hearing at which Williams took the Fifth Amendment last August was "a typical orchestrated strike force hearing wiwth sympathetic guidance from Mr. [Marty] Steinberg, a former strike force chief."

At the hearing, subcommittee investigator Jack Key testified that an organized crime informer told him Williams was "controlled by the Kansas City outfit." He also introduced into the record a goverment document that said Williams "was under the complete domination of Civella. Williams will not act contrary to the wishes of Civella apparently because of both self-interest and fear."

Steinberg then asked Williams a series of questions, including whether Civella told him to help manipulate a $91 million transfer of Teamster funds to Dunes casino owner Morris Shenker in 1978.

Brown, Williams' public relations aide, said Williams has "repudiated repeatedly" any connections to Civella. "Who knows, maybe it's a vendetta," Brown said. Wadden said his client's name is mentioned only once in a series of affidavits and thousands of pages of wiretap transcripts on file in federal court in Kansas City, and that is a reference to someone "believed to be" Williams.

The attorney also criticized Key's testimony as "hearsay, uncorroborated statements." And, although he would not comment on the investigation of the alleged transaction with Cannon, he added: "We welcome any grand jury investigation of pension fund loans because they will clear Mr. Williams' name of the allegations that are floating around."

Steinberg, chief minority counsel of the subcommittee, said Williams was called as part of the subcommittee's oversight hearings because he had been a trustee for 22 years. Steinberg noted evidence cited in a Labor Department report that the new Teamster pension fund trustees were being influenced by those who had resigned. "Mr. Williams was there to see if he still had influence on the new people. He declined to answer the questions."