President Carter said yesterday that he personally recommended to his brother, Billy, that he disclose his financial arrangement with the Libyan government.

Making his first public comments on the controversy stirred by Billy Carter's registration as a foreign agent for the Libyan government, the president said Billy told him of his activities for the Libyans just recently -- but he did not say exactly when.

"Just a few days ago, I recommended to Billy that he go ahead and make a complete revelation of what happened to the Justice Department," the president added following an appearance at a Democratic fund-raiser in Jacksonville, Fla. "He thought it over for a while and then decided to do so. But I did not know about the activities before that."

White House officials had asserted earlier that the president did not know that Billy had received $220,000 and other gifts from the Libyans until Monday, when Billy Carter filed his formal registration statement with the Justice Department in response to a court order obtained the same day.

Carter White House aides have also had several other contacts with Billy concerning his Libyan activities and the Justice Department investigation of them. National Security Council staffers briefed a close associate of Billy Carter about Libya prior to a 1978 trip, and the president was told of the trip while Billy and his friend were en route.

Then, several weeks ago, Billy Carter talked to White House counsel Lloyd Cutler about the Justice Department investigation. Cutler told Billy Carter to get a lawyer and subsequently spoke several times with the two attorneys Carter hired.

Asked in Jacksonville yesterday whether he thought it proper for Billy to have taken the $220,000, the president told reporters who stopped him as he was leaving the fund-raiser: "I don't want to comment on that part of it. I think it was a regrettable thing to have happen."

In addition to the cash, which he characterized as installments on a promised $500,000 loan. Billy Carter said he received almost $3,000 in gifts and nearly $16,000 in travel expenses from the Libyans for work done during the past two years. He also disclosed that he had been dickering with Libyan officials about an increased oil allocation for the Carter Oil Co. of Jacksonville although nothing has come of those efforts thus far. o

"A New York businessman told The Washington Post yesterday that the contacts with Charter Oil began last year after Billy sounded him out about any oil companies that might be interested in obtaining oil from Libya.

The businessman, Jack E. McGregor, who was then executive vice president of the Carey Energy Corp., declined to say, however, whether the president's brother detailed the reasons for his confidence in securing oil commitments from the Libyans.

An oil Marine Corps friend of Billy, McGregor said Carter first approached him about the subject at a meeting in Washington on April 26, 1979. Bill Carter had just been released, on April 23, from seven weeks' treatment in the Long Beach, Calif., Naval Hospital's alcoholic rehabilitation center.

"He came to me as an old friend and sometimes adviser," McGregor said. "It was I who arranged for Billy and appropriate Charter Co. officials to talk."

The president said he had not been aware of Billy's activities before Billy recently brought them to his attention, presumably near the conclusion of the Justice Department's investigation of him for his failure to register as a foreign agent.

"As you know, Billy leads a life of his own," President Carter said. "I didn't know about it and he did not confide in me about his activities. I just hope that he doesn't get hurt too much."

After registering this week, Billy Carter said that he took the money from the Libyans, $20,000 in January and $200,000 in April, because he "needed the money" and couldn't get a bank loan. "I spent all my time the past year in the drunk tank or the grand jury," he said, alluding to his treatment for alcoholism and a federal investigation of the Carter family's peanut warehouse business.

Recalling his conversations with Billy Carter, McGregor said they talked generally at first about all sorts of possibilities, including "nondomestic oil companies."

Eventually, probably at a follow-up meeting with Billy in Washington on June 27, 1979, McGregor said he recommended that Billy try Charter Oil, the subsidiary of a fast-growing conglomerate that was then in the process of buying Carey Energy. At that point, Charter had already secured a 100,000-to-125,000-barrel a day supply from the Libyan National Oil Corp. as part of the Carey takeover. McGregor said Billy played no role in those negotiations, which were especially sticky because Carey Energy owed the Libyans $136 million for oil delivered in 1975 to its huge refinery in the Bahamas.

In any case, McGregor said he felt Charter would be interested in still more Libyan oil because of the location of the Bahamian refinery it was acquiring, "just a hop, skip and a jump across the Atlantic" from Libya, and because the customers Charter was acquiring were the type that would be interested in Libya's low-sulfur crude oil.

As a result, McGregor who was Billy Carter's lieutenant at Camp LeJeune, N.C., in the 1950s, talked to Charter Oil officials about Billy's suggestion. He said he believed Billy and Charter Oil officials first met directly in the late summer or early fall of 1979.

Carter said in his registration statement that he and a colleague, Henry R. Coleman of Plains, Ga., had been engaged in discussion with Libyan officials about increasing Charter Oil's allocation since March of 1979. But McGregor said Billy was off target by several months.

Carter and Coleman's first 1979 trip to Libya took place in September, at Libyan government expense, during the 10th anniversary of the revolutionary Arab regime headed by Col. Muammar Qaddafi. McGregor suggested that it was on that visit that Billy broached the idea of increased supplies for Charter Oil.

Now head of the Hampton-Douglas Corp., an energy-oriented investment firm, McGregor also said Billy Carter has had a number of discussions with Charter oil officials about the matter since last summer.

A Charter Oil spokesman said earlier this week that Billy Carter first walked into the company's office in March 1980 -- leaving the impression they had never talked to him before. Attempts to reach the spokesman and other officials yesterday failed.

Touching on other contacts involving Libya, Carter said in his registration statement that "before March 1979," he and Coleman consulted with two staffers of the National Security Council on "the current status of formal relations with Libya."

Elaborating on that point, William Quandt, then the NSC's expert on Middle East and North African affairs, said yesterday he briefed Coleman by telephone on three occasions in August of 1979 at the request of Phillip Wise, President Carter's appointments secretary.

Quandt said he was worried that Qaddafi might "exploit the president's brother in an effort to "embarrass [Egyptian President Anwar] Sadat or our diplomatic efforts to bring together the Camp David peace talks. I told them that if they had a choice, they should wait until Camp David was over and done with."

Billy Carter and Coleman were originally scheduled to visit Libya at the time of the September 1978 Camp David Middle East peace negotiations. Qaddafi has steadily opposed Sadat's diplomatic gestures toward Israel.

As it turned out, Carter and Coleman did not visit Libya until late Septmeber, after the Camp David talks had been completed. Quandt said he was unaware of any effort to exploit Billy Carter. He suggested it was not at all surprising for the Libyans to have cultivated a friendship with the president's brother.

"In Middle East culture, you always have to have an intermediary to conduct business and blood ties are the closest ties there are," he said. For the Libyans to use the president's brother to try to improve diplomatic relations would be "a simple, traditional, Middle Eastern pattern," he said.

Quandt said he only spoke with Billy Carter for a few minutes when Carter came onto the line during one briefing and declared, "I don't need to be told how to conduct my affairs." Carter claimed to know more about Libya than Quandt did, Quandt recalled.

Subsequently, in late September 1978 when Carter was on his way to Libya, State Department desk officer Alan Roy called White House aide Tom Beard to ask if the president knew the purpose of the trip and who was accompanying Billy, according to Beard.

Beard said yesterday that he was told by the president's secretary, Susan Clough, that the president knew nothing about the trip.

However, Beard said the president passed on instructions to notify the U.S. Embassy in Tripoli that Billy's visit was not an official trip and that his brother should be shown "no courtesies other than those normal for a visiting American."

President Carter also wanted someone "to get Billy off to the side" once he got to Tripoli "and explain our relations with the Libyans," Beard said. Beard said a State Department official did brief Billy Carter in Libya.

Of the NSC briefing, Beard said yesterday that similar briefings are provided "all the time" for foreign-bound businessmen. "I've done that plenty of times," he said. "It's not that big a deal."