The White House is exploring the possibility of an agreement with the Soviet Union to suspend testing of antisatellite weapons for one year, according to informed sources.

The two countries over the past 10 months have had two rounds of negotiations on developing a formal comprehensive treaty covering such weapons, but little progress has been made, sources said.

However, the White House recently proposed - in conjunction with the possible upcoming summit meeting between President Carter and Soviet President Leonid I. Brezhnev - that the two countries try for an interim understanding on testing alone as one way to break the ice on the more formal antisatellite discussions.

Such a temporary agreement would also add to the importance of the summit, though sources said yesterday U.S. negotiators would not rush any understanding just to have it ready for the Carter-Brezhnev meeting.

A major stumbling block for the United States in the antisatellite negotiations has been the lead the Soviets have built up in this type of weaponry.

Over the past five years, the Soviets have tested several types of weapons that could be used to destroy U.S. space satellites.

The United States, on the other hand, has only recent begun a crash antisatellite weapon development program in response to what the Soviets have already done.

Pentagon sources said yesterday that U.S.-designed weapons are still a year away from testing so the planned suspension agreement with the Soviets would have no immediate effect on the program.

Both the United States and the Soviet Union depend on space satellite systems to support their strategic and tactical military systems.

U.S. satellites, for example, would provide the first warning of an attack of Soviet ICBMs on the United States. They also provide navigation aid to U.S. missile launchers and worldwide communication capability to military forces.

Under a variety of previously signed treaties and agreements, the United States and the Soviet Union have said they would not place nuclear weapons in outer space or interfere with each other's satellites that were designed for peaceful uses or verification of compliance with arms control agreements.

The 1963 Limited Test Ban Treaty also bars nuclear explosions in space.

Based on these undertakings, the United States determined in past years it had no need for developing weapons that could be used against Soviet satellites. A two-launch pad system deployed in the Pacific for use against a space-orbiting Soviet weapon was dismantled in 1975.

Two years ago, however, U.S. intelligence found signs that the Soviets were testing antisatellite weapons and an American program was quickly initiated.

At the same time, the United States approached the Soviet Union with the suggestion that talks begin on a new agreement that would bar testing and deployment of weapons that would destroy the other side's military satellites.

A comprehensive antisatellite treaty poses severe problems, particularly since verification of any deployed systems would be difficult.

Unlike the Strategic Arms Limitation Treaty, where thousands of weapons are involved, a handful of antisatellite weapons could be used to knock out the few key satellite targets necessary to maintain command, control or guidance of important military systems.

The current assymetry, where the Soviets have tested systems and the United States has not, also created problems for U.S. officials seeking a unified negotiating position acceptable to the Pentagon and Capitol Hill.

The Pentagon reportedly has balked at any long term ban on testing.

Officials of the U.S. Arms Control and Disarmament Agency, however, have maintained that the Soviet satellite-killer systems do not pose a threat to key U.S. military satellites because they have relatively short ranges. U.S. satellites will be located so far out in space that the Soviet weapons could not reach them, according to ACDA sources.

These same sources have maintained that the planned U.S. satellite killer system will be more advanced than the Soviet one and once tested, no verifiable agreement to bar deployment on either side could be reached.

Thus the ACDA hope for reaching an agreement had been based on the United States not testing the weapon now in development.

The only accepted means of verifying and antisatellite ban, one key administration source said yesterday, was at the testing stage. Once the other country has successfully tested such a weapon, the source added, it would be almost impossible to determine whether deployment has taken place and how many such weapons have been put into operation.

The U.S. Satellite-killer development program has included exploring use of a non-nuclear missile and high energy lasers as means of destroying Soviet systems.

An administration source said yesterday that the proposed one-year test suspension might be accompanied by some statement of principles on restraint in this area of weaponry to be followed by both sides.

Several sources emphasized that the one-year test ban is looked upon as a means of getting serious negotiations started and not as an end in itself.

The Pentagon, along with its satellite killer, has research under way to give U.S. military satellites defensive systems. Since satellites take so long to develop and then launch, it will be years, however, before those in space have such things as radar and laser warning systems against missiles aimed at them.