Guillermo Vilas, the world's fifth-ranked tennis player, was suspended for one year yesterday and fined $20,000 for accepting guaranteed appearance money for a tournament in Rotterdam, the Men's International Professional Tennis Council announced in Paris.

The amount of the under-the-table payment was not announced, but sources told The Washington Post that Vilas' representative and coach, Ion Tiriac, had accepted $100,000 for Vilas to participate in the ABN Wereldtennis tournament March 14-20.

Vilas, of Argentina, is the first performer to be suspended for accepting a guaranteed appearance fee, a practice rumored to be commonplace in professional tennis. Vilas has 30 days to appeal the suspension or he will be banned from all Grand Prix and Davis Cup events, although he still can play in exhibition matches, according to a council spokesman in New York.

"After an investigation of several months we have formal proof (against Vilas) provided by the organizers themselves," Philippe Chatrier, president of the International Tennis Federation, told a Paris news conference. Chatrier also said the organizers of the Rotterdam tournament had been fined $10,000. The effective date of Vilas' suspension depends on whether he decides to appeal. Vilas has denied the charges, Chatrier said.

Jim McManus, director of player and tournament services for the Association of Tennis Professionals, said the ATP had no immediate comment on Vilas' suspension. He said he did not know of any other players under investigation for accepting appearance guarantees.

However, Ivan Lendl, the world's top-ranked player, is also reported to be under investigation for accepting payments to participate in a Grand Prix tournament in Milan March 21-27. International Tennis Federation sources said the Milan tournament is under investigation. Lendl and his coach, Wojtek Fibak, have declined comment.

According to widely circulated reports in recent years, several smaller tournaments on the Grand Prix tour routinely give name players guaranteed amounts to participate in hopes that star players will help generate gate receipts.

Although players are permitted to accept fees for commercial endorsements and promotional appearances, guaranteed fees for participating in matches are prohibited.

Vilas' suspension was the second in as many days of a major tennis professional. Chatrier also announced formally that Yannick Noah, winner of the French Open tournament, will be barred from competition for 42 days from June 13 to July 25, which means he will be unable to play for France against Paraguay in the Davis Cup quarterfinals July 8-10.

Noah, who will not appeal the suspension, was set down for refusing to appear for two matches in the Nations' Cup tournament in Dusseldorf last year. Noah's suspension was seven days shorter than the 49 days originally reported. He was fined $20,000. Officials said Noah was given the choice between an 84-day suspension during which he would be allowed to play exhibition matches or the 42-day ban on all professional activity.