Defense attorneys for Sgt. Clayton J. Lonetree have asked Marine authorities to set aside his conviction and 30-year sentence for spying because the jury was "inflamed" when it was told that Lonetree was the first Marine ever to have faced espionage charges, according to attorney William M. Kunstler.

The defense discovered that four other Marines had been punished for espionage-related activities in the past five years, Kunstler said.

The move comes as Staff Sgt. Robert S. Stufflebeam, Lonetree's former immediate superior at the U.S. Embassy in Moscow, faces charges of sexual improprieties and of failing to report contacts with Soviet nationals. If convicted, he could receive a 14 1/2-year prison term.

United Press International reported from the pretrial hearings at the Quantico Marine Base that Stufflebeam's defense yesterday failed in its bid to suppress his confession to having sex with Soviet prostitutes while stationed in Moscow in 1985.

Defense attorney James Bagley had argued that Stufflebeam, 25, of Bloomington, Ill., was tricked into admitting sexual encounters as part of a bigger Naval Investigative Service probe into alleged espionage by Marine guards.

Lonetree's voluntary admission that he had made contact with a member of the Soviet secret police brought a wide-ranging investigation and led to the recall of the entire 28-member Marine guard contingent stationed in Moscow. Lonetree, 25, became the only Marine to stand trial for espionage.

A spokesman at Quantico, where Lonetree was convicted last month on 13 counts of espionage and related charges, confirmed that defense lawyers had submitted the request for a stay of sentence and conviction as part of the "total defense package" to be considered by Lt. Gen. Frank E. Petersen. Petersen may dismiss or reduce the sentence and conviction.

Kunstler said four Marines had been punished for "espionage-related offenses" since 1982. Such offenses might include initial contacts offering to sell information to the Soviets, as opposed to actually handing over material.

The highest sentence imposed in these cases was a two-year jail term, he said. "These facts were never revealed to us or the jury by the prosecution. {Lonetree} was said to be the first Marine ever convicted of espionage. Technically he was, but there have been others convicted on espionage-related activities," said Kunstler.

Lonetree, from St. Paul, Minn., was convicted of passing sensitive information to a Soviet secret police agent while guarding U.S. embassies in Moscow and Vienna between 1984 and 1986. He received a 30-year prison term and was fined $5,000, reduced to the rank of private and dishonorably discharged.