A Soviet ship has recovered at least two pieces of debris from the floor of the Sea of Japan near where a Korean airliner was shot down almost two months ago.

U.S. officials said a Soviet deep-sea salvage vessel on Wednesday hoisted a piece of metal and then lifted a second object in a net from the ocean floor. The salvage operation was witnessed from nearby U.S. Navy ships, although the Soviets arranged several of their own ships around the salvage effort in an apparent attempt to shield it from sight.

Administration officials said they cannot say for certain that the Soviet Union has found the first wreckage from the downed jet, but the Soviets are operating only about five miles from an area the U.S. Navy had searched intensively.

Dozens of ships from the two countries have been competing in the increasingly frigid northern waters to find the wreck-age since the Soviet Union shot the airliner down on Sept. 1, killing 269 passengers and crew.

"We became aware of the possibility they were onto something, when they started screening their ships," said one official who asked not to be identified. "Whatever they've found, they're not being forthright about it."

The official said the United States would repeat its requests to the Soviet Union to share anything it finds with international aviation experts, but he did not hold out much hope for that.

The Soviet discovery came as U.S. officials were close to calling off their search, which currently involves seven Navy and Coast Guard vessels and three leased Japanese ships.

The U.S. naval force recently finished a methodical search of a 65-square-mile area that had been considered the likeliest location of the plane, and snow, rain and high winds and seas now are hampering search operations.

The Soviet Union shot down Korean Air Lines flight 007 at night after it strayed into Soviet airspace, and the action provoked a storm of international condemnation. The Soviets claimed the commercial jet was on a spy mission, while South Korea and the United States said it had inadvertently strayed over Soviet territory.

Both nations hoped the wreckage would provide more information about the jet's last hours, and their competing searches were charged with political significance.

U.S. officials said yesterday that the Soviets recovered their objects in international waters 18 to 20 miles north of Moneron Island and about 14 miles west of Sakhalin Island, just outside Soviet territorial limits.

The United States, using sonar, submersible cameras and sophisticated navigational aids, had searched an area northwest of Moneron Island just five to six miles southwest of the Soviet find.

"It's in the general area," one official said. "Ours was an estimation at best, anyway."

Pentagon officials said they do not know how the most recent developments will affect their operations. "We are proceeding until so ordered to stop ," said one. "The thing may be in 100 pieces."

Based on radar and radio signals on the night of the crash, U.S. officials had said they believed the plane fell toward the ocean in one piece rather than exploding in midair. But they acknowledged that they can only make estimates or intelligent guesses about the plane's condition and current location.