The FBI is investigating a suspected bribery scheme involving Teamsters union figures and Senate Commerce Committee Chairman Howard W. Cannon (D-Nev.).

Sources said the investigation involves a bill to deregulate the trucking industry that has been languishing in Cannon's committee since its introduction last year.

FBI agents in Chicago and Las Vegas have been focusing, sources said, on a reported effort by Cannon to obtain a loan from the Teamsters' Central States Pensions Fund.

In a statement issued by his office here late last night, Cannon unequivocally denied any connection between his handling of deregulation legislation and the transactions under investigation.

The investigation was said to be in its initial stages and not yet presented to a grand jury.

The case has no connection with the FBI's undercover "sting" operation that has brought eight other members of Congress under investigation for potential bribery charges.

ABC News, which first reported the probe involving Cannon last night, said the FBI suspects that Allen Dorfman, a Teamster crony with alleged connections to organized crime, found a way to reward the Nevada senator for steering the deregulation bill into his committee.

The deregulation measure was jointly sponsored last year by President Carter and Sen. Edward M. Kennedy (D-Mass.).

Kennedy had initially argued that the bill should be considered by his Senate Judiciary Committee since the legislation would repeal a special antitrust exemption granted the trucking industry in 1948.

Cannon, however, argued that the bill was a "transportation" measure that should be sent to the Commerce Committee.

According to ABC News, the FBI is investigating whether Cannon was "enriched through a land transaction" in Las Vegas.

Cannon last night disputed any connection between the deregulation bill and a contact he made with Dorfman about the land matter. He said that he introduced a trucking deregulation bill of his own last Friday which "is being strongly opposed by the Teamsters."

The administration-Kennedy bill, which was hotly opposed by both the Teamsters and the trucking industry last year, would end a complex system of federal rules that the president has said cost consumers $5 billion a year.

Cannon said in his statement that the Las Vegas land in question was simply the subject of a dispute "involving a homeowners' group of which I was one member." His press secretary, Michael R. Vernetti, said the Teamsters owned a five-acre tract across the street and wanted a zoning variance to put up three high-rise apartments.

The zoning change was denied, but the homeowners decided to try to buy the land to protect themselves in the future, Vernetti said. He said Cannon contacted Dorfman to find out whom to approach to make the purchase. Vernetti said Dorfman directed Cannon to a company in charge of investing Teamster pension money, but the offer was subsequently turned down.

Last October, Cannon warned the Interstate Commerce Commission at a workshop on trucking deregulation to take no major actions in that direction until Congress had acted.

Urged on by both Cannon and the Teamsters, the Senate Appropriations Committee that same month formally directed the ICC not to implement any new trucking regulations before Congress dealt with the issue.