Ronald W. Pelton, a former National Security Agency employe accused of espionage, came back from a four-hour interview with two FBI agents late last year and told his girlfriend, "They may want me to work for them," according to testimony presented today.

When the agents called him back for more discussion about his alleged espionage activities for the Soviets, Pelton told the woman, Ann Barry, "They may move me and change my identity is what it comes down to," according to the testimony, which was based on wiretaps of Barry's apartment.

The testimony today was part of a hearing in U.S. District Court here in which Pelton's attorney is seeking to have Pelton's statements to the FBI suppressed by arguing that the agents misled him into thinking he could escape prosecution by talking

Pelton's apparent assumption that the government would turn him into a double agent was wrong. The 44-year-old Pelton was arrested Nov. 25 on charges of selling extremely sensitive intelligence information to the Soviets from 1980 to 1985.

FBI agent David E. Faulkner testified today that FBI agents on the case "never discussed" the possibility of not prosecuting Pelton but were seeking only to elicit a confession so he could be prosecuted.

Without a confession, Faulkner said, his FBI superiors had told him he had no probable cause for arrest. Pelton, described by a former NSA supervisor today as "extremely intelligent," correctly guessed the situation, telling the FBI agents, "You don't have a case," Faulkner testified.

Where he went wrong, prosecutors contend, was in assuming that he could discuss payments, expense money and contacts with the Soviets and not be prosecuted so long as he did not specify what information he passed on.

Pelton's court-appointed attorney, Fred Warren Bennett, argued today both that FBI agents misled Pelton and that they failed to advise him of his rights to remain silent and to legal counsel, which Bennett said the law requires.

Faulkner testified that Pelton was not in custody at the time of the interview, although he was under strict surveillance.

Faulkner said FBI agents were following Pelton's car and monitoring four listening devices planted at the boat dealership where Pelton worked, his girlfriend's home, her telephone and Pelton's car.

Faulkner also testified that Pelton was fully aware of the possibility of prosecution.

Phillip Ambler, an NSA analyst who worked with Pelton for six years, testified that Pelton's ability to recall technical information was so "remarkable" that Pelton's superiors "would contact him directly to do projects or answer questions."

Faulkner said Pelton told him just before his arrest that walking into the Soviet Embassy in 1980 when he allegedly began his spying career was "the biggest mistake of my life."