The trust for President Carter's share of the family peanut business allows trustee Charles Kirbo, a longtime close friend and adviser, much more lceway in managing the holdings than previously reported, the White House disclosed yesterday.

The White House also announced yesterday that:

General Services Administration head Jack M. Eckerd, a wealthy Republican whom Carter asked to stay on, has resigned because the President would not let him name his own top deputies. Sources close to Eckerd disputed the White House account of the resignation and Eckerd issued a statement implying that the White House was injecting politics into the agency.

The President will send a delegation to Vietnam to get the "fullest possible accounting of missing Americans.

White House aides hinted that it omatic recognition of Vietnam.

FBI Director Clarence M. Kelley will be ineligible to retain his post because he will be part of the nine-member search comittee Carter will name to hunt for a new FBI director.

The trust agreement, signed Jan. 20 but made public yesterday, instructs Kirbo to manage the President's assets without consulting or informing Cater, and in such a way that income from them "will not be substantially affected by federal legislation . . . "

It does not set any limits on what Kirbo mier, and Carter aides said Kirbo might have more options than the selling or leasing of Carter's farmland and his share of the peanut business than were originally contemplated.

When Kirbo was named trustee Jan. 17, Carter's press secretary, Jody Powell, said the President would retain ownership of his 3,400 acres of land, but it would be leased for four years at a fixed rental.

Powell also said to decide whether to sell or lease the peanut processing business the President owns with his mother and brother, and to handle the necessary leases or sales.

Yesterday, however, Powell said there might be "other options . . . that might accomplish the same purpose . . . "

"We know of no other options," he said, "but there was just a desire not to foreclose the possibility of those options."

Presidential counselor Robert Lipshutz said. "I am sure Mr. Kirbo would welcome . . . any other options which might be suggested in a positive manner that will still accomplish the basic objectives of the trust."

One reporter, noting that Kirbo has advised the President on a wide range of matters for a long time, asked what would prevent him from converting the President's holdings to securities, and then advising Carter on economic issues that might affect the value of the securities.

" . . . That is not the intent and character of the people we're dealing with . . . ," Lipshutz replied. "You're obviously talking about the integrity of the trustee and of course the President and I certainly am confident that that would be handled on the highest possible ethical basis . . . "

The trust agreement grants Kirbo "reasonable compensation" with no amount specified, and expresses Carter's hope that "the purposes of this trust can be accomplished without the trustee's having to sell the farmlands."

It also asks Kirbo to carefully weigh the effect of any decisions upon Billy Carter, and expresses Carter's hope that the business can be preserved for his sons, "especially James Earl Carter III," if they wish to become a part of it in the future.

On other matters, Carter met for 40 minutes yesterday with representatives of the National League of Families, which includes the next-of-kin of some 2,500 Americans still Southeast Asia.

He told them he would send a delegation to Vietnam, but gave no timetable, aides said.

National security adviser Zbigniew Brzezinski sat in on the meeting. An aide to Brzezinski was asked later whether diplomatic recognition of Vietnam was discussed.

He did not respond directly, but said, "When he delegation goes to Vietnam, it will consider a whole range of outstanding issues." Asked to reply directly, he smiled and said, "I think I've answered the question."

Carter also met briefly with Ellsworth Bunker, the ambassador-at-large who heads the U.S. negotiating team on the Panama Canal, and expressed hope that the United States and Panama will make quick progress toward a new treaty. Those talks resume Monday.

When he left in mid-afternoon for his first trip to his home in Plains, Ga., since becoming President, he became the first President to fly on one of the super-secret emergency command post jets kept at Andrews Air Force Base.

Those jets are converted 747s designed to keep the President and his advisers mobile and in command in case of nuclear war. Aides said Carter wanted to check out the facilites avilable.

The President plans a quiet weekend to work on federal budget modifications, aides said. He will make no announcements until he returns to Washington Sunday night, they said.