The Justice Department attorney who directed the investigation of Billy Carter's dealings with Libya said yesterday that Attorney General Benjamin R. Civilett's discussion of the case with President Carter had no effect on the decision not to seek criminal charges.

Joel S. Lisker, chief of the department's foreign-agent registration unit, said in a phone interview that he received no instructions from Civiletti about how to handle the case. In fact, he said, he had his immediate superiors were still discussing possible criminal charges or formation of a grand jury to look into Billy Carter more than two weeks after Civiletti's June 17 conversation with the president.

Civiletti's surprise announcement Friday that he discussed the case with President Carter already has triggered an internal Justice Department investigation into Civiletti's conduct and conceivably could bring about a separate FBI investigation under the special-prosecutor law.

Both Civiletti and White House officials said repeatedly before Friday that they had not been in contact about the Billy Carter investigation. The attorney general's sudden reversal raised the question of whether his talk with the president might have reached the level of obstruction of justice or violated some department regulation.

The president called his brother on June 28 and July 1 and urged him to register as a foreign agent for Libya, according to the White House. A question the Justice Department's office of professional responsibility is likely to study is whether Civiletti's advice -- that Billy Carter probably would not be prosecuted if he registered -- caused the president's call and his brother's registration, and thereby cut off the normal flow of the investigation.

Lisker said yesterday, however, that he had decided by early July to recommend a civil action against Billy Carter to force his disclosure that he accepted $220,000 from the Libyans.

Philip B. Heymann, head of the criminal division, has said he met with Lisker, and three other prosecutors, John C. Keeney, Mark Richard and John L. Martin, to discuss options in the case.

Lisker said the meeting was held shortly before Heymann left the country for a conference July 4 and described the discussion as "open and absolutely uncontrolled." There was some discussion of criminal charges because one participant felt Billy Carter had been evasive in his dealings with Justice.

Consideration of a grand jury was dropped after the prosecutors estimated it could take six to 18 months to resolve the issue that way. "If we wanted to cover up something for the administration we could have started a grand jury and the whole thing would have remained secret until after the election," another participant said.

The consensus at the end of the meeting was to follow his recommendation and proceed with a civil action to force Billy Carter's registration, Lisker said.

He said he discussed his handling of the case only twice with the attorney general, once on June 11 to tell him Billy Carter had acknowledged receipt of the $220,000, and again on Thursday, just before a Civiletti press conference.

"I ws the only one who worked on this case," Lisker said. "And from the beginning it was handled just like any other registration case. To make it a special case wouldn't have been fair to Billy Carter."

The attorney general's brief discussion of the case with the president "didn't head off anything," he said.

Michael E. Shaheen Jr., head of the department's office of professional responsibility, said yesterday that FBI agents will have to interview Civiletti, the president and anyone else with whom they may have discussed their June 17 exchange. "We will pursue all logical leads," he said. "I can't imagine certifying the investigatory product without interviewing everyone involved."

Civiletti issued a statement yesterday pledging his full cooperation with Shaheen's inquiry and instructing other department officials to do the same.

He said he was certain Shaheen "will do a thorough job on this investigation and, having done that king of job, will find no impropriety."

Because Civiletti is the subject of the investigation and Deputy Attorney General Charles B. Renfrew took part in the deliberations on the Billy Carter case, Shaheen will file his report with Solicitor General Wade H. McCree.

Some prosecutors said yesterday they could see how questions of propriety are raised by Civiletti's discussion of the case with the president, but they said the facts disclosed so far make a criminal violation sound unlikely.

In the same vein, a department official familiar with the special prosecutor law said yesterday that it seemed doubtful the information about the Civiletti-president talk was specific enough to force the preliminary FBI investigation called for under the law.

A special prosecutor was appointed last fall to investigate allegations that White House chief of staff Hamilton Jordan used cocaine at a New York nightclub. The charges were not substantiated.

Under the law, high-ranking White House and other executive branch officials must be investigated if the attorney general receives "specific information" about a possible crime. After the preliminary FBI inquiry, the attorney general either closes the case or asks a special court to appoint a special prosecutor.

At the White House yesterday, press secretary Jody Powell said the Tuesday white paper on the Billy Carter affair had been released before the president had fully checked his records.

Powell added that "if we had waited," the erroneous July 22 statement that there had been no conversation between the president and the attorney general would "not have been made."

He used that example to illustrate why the White House is slower now responding to questions that have arisen in the matter.

"We want to be as accurate as we can," Powell said, but added that -- as with the Civiletti conversation -- the president was prepared to correct any misinformation that got out.

He emphasized, as he has done before, that the president and his aides were not trying to cover up or hide anything.

"We are dealing with the best recollections" of people, Powell said.

For example, he noted that national security adviser Zbigniew Brzezinski still "can't be sure" who asked him to contact Billy Carter in November.

The Washington Post reported yesterday that the White House believes the "most likely possibility" is that the president -- at the suggestion of his wife -- gave Brzezinski the suggestion.

Powell at his press briefing yesterday said he was "not going to discuss the hypothesis" of the story.

"I don't have anything that I want to go on the record with at this time," he said.

Powell did take issue with The Post article's assertion that when the July 22 white paper was released, White House aides emphasized that it was Brzezinski's idea alone to contact Billy Carter.

"That is not correct," Powell said yesterday.

He said the White House had not put Brzezinski forward as the man who originated the idea -- only as the one who had placed the call to Billy Carter.

To support his position, Powell pointed to a statement he had made at the July 22 press briefing where he had told reporters, "I cannot give an answer on whose idea" it was to approach Billy.

Powell also announced yesterday that the White House hopes to respond this week in writing to two House committees that have sent detailed questions to the president about the Billy Carter affair.

The committees, Judiciary and Foreign Affairs, have before them resolutions of inquiry and must file their reports on them by July 31.

The questions cover all aspects of the affair including the president's "conversations and actions" on the matter.

Powell said, "The president intends not only to comment fully but also to provide detailed responses which will supply substantially all of the information requested. . . ."

Powell added that he hoped the material would eventually be made public by the committees because "we feel we have done the maximum that was proper" and "full public disclosure will show that."

In other developments yesterday, one group called for Civiletti's resignation and some members of Congress joined the criticism of the administration's public handlng of the case.

The board of Americans for Democratic Action, which has enthusiastically endorsed Kennedy over Carter, passed a resolution calling for Civiletti to step down. It said the attorney general had shown favoritism to the president in discussing the case that "disqualifies him as the nation's chief law enforcement officer."

Sen. Robert C. Byrd (D-W.Va.), the Senate majority leader, said it was "a very serious mistake for Civiletti and the president "not to have made absolutely clear what the facts were in the beginning. Most unfortunate."

Referring to the planned Senate investigation of the Billy Carter case, Byrd said: "We Democrats don't want delay. It's in our interest to expedite this, not to sweep anything under the rug . . . If mistakes were made and poor judgment exercised, it should all be laid out as soon as possible. It shouldn't be extracted day by day and tooth by tooth. Delay only compounds the problem."

Some people may be making a judgment on the highly publicized case too soon, he added. "It's very easy to believe in a situation like this that every wind is a hurricane, which it is not," he said.

Sen. Bob Dole (R-Kan.) said the Civiletti disclosure of his conversation with the president makes "a whole new ballgame." He said a special counsel "with impeccable credentials" should be appointed to lead the committee investigation.

He added that he assumed there would be a call for a special prosecutor but said he thought that would delay things too much.