The administration yesterday put into abeyance the frantic negotiations it began last week to save its proposed sale of radar planes to Saudi Arabia and assigned President Reagan's national security affairs adviser, Richard V. Allen, to work out by midweek a detailed compromise plan for staving off a congressional veto of the $8.5 billion deal.

In other action yesterday, the White House announced that the president will have his first formal news conference in three months sometime during the next two weeks, and said that the president will keep to his schedule of announcing later this week whether to go ahead with both the B1 bomber and the MX missile programs.

On negotiations on the radar planes, called Airborne Warning and Control System or AWACS, informed sources said a team headed by Allen was working through the weekend to revise the sales agreement to satisfy congressional demands for greater U.S. control over the planes without violating Saudi Arabia's insistence that its sovereignty not be infringed.

At this point, the sources stressed, it still is too early to tell whether the differences can be bridged in a mutually satisfactory manner. For the moment, they added, the flurry of negotiations that opened Thursday and Friday are, as one source put it, "on hold" until the various parties see what Allen and his aides come up with.

Formal notification of the administration's intention to sell the AWACS and other sophisticated aircraft equipment is scheduled to go to Congress Wednesday. The sale can be blocked if both houses vote against it within 30 days of the notification.

Concern about the possible threat of the equipment being used against Israel or falling into the hands of U.S. foes has produced an apparently irreversible majority against the sale in the House. A majority of the Senate also is leaning against the deal, but the administration hopes the situation in the Senate can be changed if the Saudis agree to include American technicians in the crews manning the AWACS surveillance gear.

The sources denied reports that Saudi Arabia, through its representative here, Prince Bandar bin Sultan, had rejected joint control or had said it would permit American training personnel to fly on AWACS missions only for a limited period after delivery of the planes in 1985 and 1986.

They conceded that the Saudi reaction had been hostile initially and remains cool. But, the sources continued, the Saudi government, on the basis of Friday's discussions, has agreed to keep an open mind about a compromise until the administration comes up with a detailed plan.

In agreeing to wait, the sources said, the Saudis were influenced by a desire to salvage the other parts of the package, even if the AWACS deal falls through. In addition to the radar planes, the sale calls for providing the Saudis with range-enhancing fuel tanks for the F15 jet fighter-bombers they are buying from the United States, aerial refueling tankers and Sidewinder air-to-air missiles.

The sources also said that another idea floated by the administration--sending a high-level delegation to Saudi Arabia for negotiations--still is under consideration but seems unlikely because of Saudi coolness toward the proposal.

They said the Saudi preference is to try to work out the problem in Washington. If that can be done, the sources added, there still is a possibility of sending a delegation to Saudi Arabia, to formalize an already agreed-upon compromise under ceremonial circumstances that might influence the Senate vote.

If it is decided to go ahead with such a public relations mission, the sources added, the delegation would include influential members of Congress and would be headed by Secretary of State Alexander M. Haig Jr. or another official of comparable stature. However, the sources stressed, no decisions will be made about a high-level visit until it becomes clearer whether the administration can hammer together a compromise that pleases both the Saudis and the Senate.

In a briefing at the White House yesterday, spokesman David Gergen said the president on Monday will endorse a sweeping revision of federal criminal laws when he speaks before the International Association of Chiefs of Police.

In the speech, to be delivered in New Orleans, the president will call for changes in bail procedures to allow judges "more flexibility to hold some defendants and to raise bail standards in order to make it more difficult for them to get back out on the streets," Gergen said.

Among the other topics in the speech will be the need to crack down on drug traffic, especially by taking drug shipments at sea, possibly by using military forces.

The president will also ask for some changes in the "exclusionary rules" by which evidence is kept out of court if it has been obtained in ways that violate a suspect's legal rights.