The White House acknowledged yesterday that President Carter discussed "low-classification" State Department cables with his brother, Billy, concerning Billy Carter's first trip to Libya in September 1978.

A White House spokesman said, however, that the president "does not now recall" having shown his brother the cables or having given him copies of them.

The President's latest disclosure in the controversy about his brother's ties to Libya was prompted by revelations earlier in the day on Capitol Hill at a meeting of the House Judiciary Committee.

Justice Department records turned over to the committee Tuesday, committee members said, showed that Billy Carter told government investigators last winter that he had copies of State Department cable traffic about his Libyan trips and that "Jimmy gave them to me."

Voicing sharp dismay about the contents of that interview, conducted last Jan. 16 at Billy Carter's Buena Vista, Ga., home, the Judiciary Committee quickly demanded a formal explanation from the president as it approved a resolution of inquiry into Billy Carter's activities.

Committee Chairman Peter W. Rodino Jr. (D.N.J.) said the resolution could not come up on the House floor before Aug. 19, after the Democratic National Convention.

Meanwhile, the Justice Department took back the documents, drawing protests from both Democratic and Republican committee members.

In its initial response to the new furor, the White House issued a statement that deputy press secretary Ray Jenkins read to reporters yesterday afternoon.

"The president's best recollection," the statement said, "is that the only State Department cables he has ever discussed with Billy Carter are low classification cables from our embassy in Libya reporting on Billy Carter's first trip to Libya in September of 1978 and indicating that the trip had gone well from the embassy's point of view.

"The president does not now recall whether he saw the texts of these cables himself or heard about them from others. He does not now recall showing the texts to Billy Carter or giving him copies."

Jenkins said the cables were probably classified "confidential" or "limited use only," which are relatively low rankings in the government's classification system. Jenkins also said it was his "impression" that the president had discussed these cables with Billy Carter shortly after the president's brother returned from his September 1978 trip.

Rep. Harold S. Sawyer (R-Mich.) disclosed Billy Carter's account in the course of committee debate on the resolution of inquiry, which could trigger a second congressional investigation of Billy Carter's Libyan connection and the administration's handling of them. The Senate has already formed a special subcommittee to look into the matter.

Sawyer said an FBI report on the Jan. 16 interview with the president's brother showed that Billy Carter "said he had been furnished all State Department cable traffic vis-a-vis Libya and that he had them at his house."

Beyond that, Sawyer recounted, "he [Billy Carter] said he received them from the president of the United States."

Sawyer said later that he did not recall whether Billy Carter pinpointed any particular trip or date for his claims. But the president's brother did tell his interrogators that "'Jimmy gave them to me,'" Sawyer told reporters during a break.

"I'm precisely sure of what I'm saying," Sawyer added. "I'm a trial lawyer. I read documents very carefully."

Justice Department officials took their four volumes of documents back from the committee Tuesday evening, apparently with no intention of releasing them again until the full House acts on the resolution of inquiry. But several other committee members who had a chance to inspect the records before they were withdrawn corroborated Sawyer's account.

"Either it's a gross violation of the communications statute by the president or Billy Carter is guilty of a felony" in lying to government investigators, Sawyer contended at one point. He said later that he assumed the cables were classified.

"I wouldn't be surprised if he [Billy Carter] furnished them to the Libyan government," Sawyer told reporters. He said the FBI report on the interview showed that the president's brother mentioned the cable traffic in support of a claim that his visits to Libya had been "good for the United States."

Sawyer said the Justice Department records showed that Billy Carter had not been telling the truth in the Jan. 16 interview, when he was asked how much he had been paid by the Libyans.

At that point, he had been paid $20,000 by the Libyans, by a check that Randy Coleman, an associate of Billy Carter, had picked up in Washington on Dec. 27, according to sources. But in the Jan. 16 interview, Sawyer said, the president's brother said he had received "only a few gold bracelets" and reimbursement of some $6,000 to $7,000 in expenses he said he incurred while escorting a Libyan delegation on a 1979 trip to the United States.

Justice Department officials evidently chose to ignore the inconsistencies.

One department lawyer who worked on the case also said he was not aware of any follow-up effort to check out Billy Carter's claims of having been given the State Department cable traffic by the president.

Joel Lisker, the head of the Justice Department's foreign agents registration unit, and an FBI agent who accompanied Lisker, simply felt that it was another of Billy Carter's "irresponsible statements," this source said.

In an interview with United Press International Lisker confirmed that Billy Carter claimed to have been given the cables by his brother. Lisker said he laid out his copies of various cables about Billy Carter's trips, and Billy responded.

"I see you've got those CIA cables. I've got them, too." Lisker said he told Billy the cables were from the State Department. He said he asked Billy where he got them, and quoted him as replying:

"They're all the same thing Jimmy gave them to me."

While the White House said the cables had a "low classification," meaning they were not to be held as secretly as higher classification material, Lisker told the Associated Press that the cables he had were not classified at all.

Presidents have routinely taken it upon themselves to declassify what they choose. But federal law prohibits other government officers and employes from communicating classified information to anyone they have reason to believe is an agent of a foreign government "unless specifically authorized by the president. . . ."

On a motion by Rep. William J. Hughes (D-N.J.), the Judiciary Committee unanimously expanded the resolution of inquiry to demand that the president provide the House with any State Department cables and other communications or memos furnished to Billy Carter "and the name of the person or persons" who gave him such documents.

A spokesman at the State Department said that except for a relatively few cables that are limited to the department, cables from overseas posts receive fairly wide distribution among U.S. government agencies.

The White House and National Security Council have their own message centers and therefore receive their own copies of diplomatic cables from overseas, another State Department official pointed out.

One White House official who had seen the cables reporting on Billy Carter's trip said the parts about Billy were "really quite innocuous," but that the cables went into other matters as well.

Commenting at the White House on another facet of the growing controversy, deputy press secretary Jenkins said that White House appointments secretary Philip J. Wise Jr. has once more checked his telephone records.

Wise, Jenkins said, found that he does in fact have a record of having received a call from Billy Carter's friend and associate in his contacts with the Libyans, Henry (Randy) Coleman, on Jan. 5, 1979.

Jenkins said Wise cannot recall the substance of that discussion, but other sources said that Coleman, presumably acting on Billy's behalf, did call Wise at some point to ask about the status of some C130 military air transports the Libyans wanted.

Billy Carter also told investigators, according to several sources, that he tried to check on the status of the C130s in a call to Wise. But Wise has said he has no recollection of having discussed the matter with Billy Carter. s

The government's refusal to grant an export license that would provide the Libyans with eight C130s -- which they paid for in the early 1970s -- has been one of the biggest sore spots in U.S. Libyan relations. The United States has refused to approve the shipment on the grounds that some C130s Libya bought in 1969 were used for terrorist activities.

In his interview with AP, Lisker confirmed that Billy Carter had told him of calling Wise about the C130s and U.S.-Libyan relations in general, but Lisker said he now believes Coleman made the call to the White House aide sometime between October and November 1978.

At the Judiciary Committee meeting yesterday, Rep. Thomas F. Railsback (R-Ill.) said he felt the committee should find out whether Billy Carter had any conversations with the president "relative to aircraft sold to Libya." h

Billy Carter was asked in his Jan. 16 interview if he had ever made any attempts to influence the president -- directly or through their mother, Lillian -- about the C130s, but the president's brother refused to answer, saying it was none of their business.

Rep. Harold L. Volkmer (D-Mo.) and Sawyer told reporters that the Justice Department documents also recounted how Billy Carter first got acquainted with the Libyans, at a meeting in Plains, Ga., several years ago with a Libyan official.

According to the records, Sawyer said, the Libyan official handed Billy an invitation addressed to "The brother of the president of the United States." Billy, according to this account, said he was invited to Libya and was told he could bring along anyone he wanted, "except Jews."