Ronald W. Pelton, a former communications specialist with the National Security Agency, pleaded not guilty today to charges that he sold the Soviet Union a wide range of U.S. intelligence secrets.

U.S. District Judge Herbert F. Murray set a trial date for March 24 and predicted that the proceeding would last seven or eight days. Asked about the possibility of a plea arrangement, Fred Warren Bennett, one of Pelton's two court-appointed attorneys, said after the hearing, "My judgment is this will go to trial."

The hearing underscored the critical nature of statements that Pelton, 44, made to the FBI during five hours of interviews in an Annapolis hotel room that ended after midnight on Nov. 25, when he was placed under arrest.

Bennett told the judge he expected that a pretial motion to suppress those statements would be the "most important" one that the defense would file.

Bennett and Warren Brown, who also is representing Pelton, suggested through their questioning in an earlier hearing that FBI agents misled Pelton by asking him if he wanted to become a double agent. They also intimated that Pelton was too intoxicated to realize what he was saying. An FBI agent testified that Pelton was neither drunk nor deceived when he talked to them.

Bennett said in an interview that he believes he has a better chance of getting the statements thrown out than did attorneys for Arthur Walker, who was convicted of espionage charges earlier this year after a judge refused to suppress statements he made to the FBI. Bennett said that, unlike Pelton, Arthur Walker spoke to the FBI over a period of three or four days and was repeatedly advised of his rights.

Bennett said he saw less of a chance of a plea bargain in the Pelton case than in the case of convicted spy John Anthony Walker Jr., whom he also represented. He said prosecutors were eager for John Walker to testify against Jerry Whitworth, also charged in the case, and were "perhaps more flexible."

The cases involving the Walkers -- the most renowned of the spying defendants this year -- have provided lawyers with a blueprint on how to handle such cases. Bennett told Judge Murray, for instance, that he and prosecutors had basically lifted from the John Walker case a protective order setting out procedures for handling of classified information.

He also said he knows from the experience of other defendants in spy cases that it's useless for him to press any further for Pelton's release from the Anne Arundel jail before his trial.

Pelton faces a maximum penalty of life imprisonment on each of five counts of espionage and 10 years for disclosure of classified information.