The FBI is attempting to learn the identity of a person accused spy Jonathan Jay Pollard said he gave classified U.S. documents on Nov. 15, three days before Pollard was confronted by investigators and asked about his alleged spying for Israel, sources familiar with the case said yesterday.

Pollard told the FBI that he delivered classified U.S. documents to a foreign government agent at the Nov. 15 meeting, according to an FBI affidavit filed in court when Pollard was arrested.

Investigators do not know what country the person was representing, sources said. One source said investigators are convinced the meeting took place and are "still looking for the person he met with." Pollard, a civilian Navy counterterrorism analyst, also has claimed he sold secrets to Pakistan and East Germany, but investigators have found no evidence to support those assertions.

Sources said the description of the person Pollard met with on Nov. 15 does not match the description of either of the two Israeli diplomats, Ilan Ravid and Yosef Yagur, alleged to be Pollard's contacts in the United States. "More than likely" there was a third person, said one source.

In related developments yesterday:

*U.S. Magistrate Patrick J. Attridge ruled that Pollard's wife, Anne L. Henderson-Pollard, posed a serious threat to national security and ordered her held without bond while awaiting trial. Attridge said there was a good chance Henderson-Pollard might flee the country if she were freed.

He noted that when Pollard was arrested Nov. 21 outside the Israeli Embassy after an unsuccessful attempt to obtain political asylum, Henderson-Pollard was with him and had in her purse the couple's birth certificates, marriage license and vaccination papers for the family cat Dusty, which was also with them.

Henderson-Pollard, 25, is charged with unauthorized possession of classified documents, an offense that carries a maximun penalty of 10 years in prison and a $10,000 fine. Assistant U.S. Attorney Charles Leeper said in court yesterday that the government may ask a grand jury to indict her for espionage, a charge that carries a sentence of up to life in prison. Pollard, 31, has been charged with espionage.

*Officials from the Justice and State departments worked on details of a plan to send a team of U.S. officials, including prosecutors and FBI agents, to Israel to interview Ravid, Yagur and other Israeli officials implicated in Pollard's alleged spying, officials said.

Charles E. Redman, a State Department spokesman, declined to disclose specifics of negotiations beyond saying that "we're in touch with the Israelis about what the next step might be and who we might send to go over there."

Redman said U.S. officials expect the Israelis' cooperation to be an ongoing process rather than a single meeting or exchange. Israeli sources have said that Israel will return any documents allegedly obtained from Pollard and will make Israeli officials involved with him available for interviews.

Pollard is in the D.C. Jail, where he was ordered held after Attridge denied him bond last week.

After yesterday's hearing, a visibly upset Bernard Henderson, Henderson-Pollard's father, said it was "stupid" to deny his daughter bond.

"All they brought out was a lot of wild stories," said Henderson, who said he had been prepared to move temporarily to Washington from Pennsylvania to be with his daughter if she had been released. "The government is not producing evidence," said Henderson, a public relations executive.

James Hibey, Henderson-Pollard's lawyer, said he may appeal Attridge's decision.

Hibey had told Attridge that Pollard's father, Morris Pollard, a prominent Notre Dame University microbiologist, was prepared to pledge a $75,000 painting as collateral for his daughter-in-law's release and that her grandfather would come here from Idaho to join in her supervision.

However, Attridge said he was concerned about the risk to national security if Henderson-Pollard divulged the contents of the classified documents her husband allegedly obtained from the Navy.

"This defendant has had access to classified documents top secret and beyond," Attridge said. If she is released, he asked, "How do you preclude further dissemination?"

Attridge called attention to allegations that Henderson-Pollard told an unidentified friend that she was going to use classified documents, including a U.S. analysis of China's intelligence operations in this country, for a business presentation to the Chinese Embassy.

The report on Chinese intelligence was in a suitcase seized by FBI agents from an unidentified friend who told the FBI that Henderson-Pollard asked that the suitcase be taken to her at a hotel where she planned to burn the documents, FBI agent Eugene J. Noltkamper testified last week. A source familiar with the investigation said the government has no evidence that Henderson-Pollard attempted to provide the Chinese with the documents.

U.S. Attorney Joseph E. diGenova told reporters after yesterday's hearing that "the evidence is pregnant with the suggestion that the documents in her possession were for use with another country."

DiGenova said prosecutors will soon begin presenting evidence in the case to a federal grand jury, which under the federal speedy trial law must decide by the end of this month whether to indict the couple.

He said the government could ask a judge for an extension of the deadline.