Former CIA officer and convicted spy Aldrich H. Ames is seeking to renegotiate his 1994 guilty plea, saying in a court filing that he agreed to a life sentence only to avert a long prison term for his wife, which would have deprived his young son of both parents.

The habeas corpus motion was drafted by Ames, who has been spending much of his free time in the law library of the maximum security federal prison at Allenwood, Pa.

John Martin, the Justice Department lawyer who supervised the prosecution of Ames and has since retired to private practice, said yesterday that the vast majority of such motions fail. A CIA spokesman said the agency was unaware of Ames's motion but would oppose it.

Ames was a veteran CIA officer who told government investigators after his arrest in 1994 that he had given the Soviet KGB the names of dozens of Russians serving as agents of U.S. and British intelligence. In return, the KGB paid him nearly $2 million over a nine-year period, according to his financial records.

U.S. officials have said that Ames's disclosures resulted in the execution of at least 10 Russian agents.

Ames's motion, filed earlier this month in U.S. District Court in Alexandria, claimed that his constitutional rights were violated by his "involuntary" plea, which contained "misstatements, errors and omissions" about his activities.

He said he was filing the motion now because his wife, Rosario, was freed from federal prison in October 1998 and has returned to her native Colombia to raise their son. In 1997, he said, he withdrew a similar motion out of fear that it would interfere with her release.

In a declaration accompanying his motion, Ames said he was "surprised" by the breadth of the espionage activities attributed to him in the plea agreement drafted by the government. "It appeared to me that I was to take responsibility for intelligence failures and compromises for which I knew I was not" truly responsible, he said.

He added that he considered raising objections to the statement but that his court-appointed attorney, Plato Cacheris, told him prosecutors were unwilling to negotiate on the facts. He said Cacheris advised him to reject the plea agreement but he accepted it because of "extreme threats" from prosecutors to seek a long prison term for his wife.

"My instinctive bonds of affection and duty to my family ruled out any other consideration or calculation," he said.

The latest confirmation of Ames's activities for Moscow is contained in a new book on Soviet intelligence, "The Sword and the Shield," based on revelations by former KGB archivist Vasili Mitrokhin. It says that Viktor Cherkashin, the KGB agent who handled Ames in 1985, said Ames's first delivery of information included "the identities of two real American agents" inside the KGB station in Washington. The book also says that Ames identified more than 20 agents.