WASHINGTON--A Soviet nuclear-powered submarine remained "dead in the water" in the Atlantic yesterday, but no smoke was seen spewing from the stricken ship, indicating a fire on board had been extinguished, Pentagon officials said.

Most of the crew members were evacuated to nearby Soviet merchant ships, and a U.S. Navy tug was in the area ready to assist if needed, officials said.

"As near as we can tell, the fire has been extinguished," said a Pentagon source, who spoke on condition of anonymity.

U.S. P-3 Orion reconnaissance planes, which have been flying over the sub 552 miles east of Bermuda through the weekend, reported that smoke stopped spewing from the vessel yesterday morning and no personnel were observed on the deck of the sub, said Pentagon spokesman Maj. Larry Icenogle.

"The sub is still dead in the water. It is not moving," he said.

Three Soviet merchant ships were near the ballistic missile-carrying submarine, a small boat was alongside the sub, and a Soviet ship capable of towing the sub also was in the vicinity, Icenogle said.

The tow ship is an auxiliary repair vessel which was in Caribbean when the fire broke out Friday morning. The ship was heading toward the submarine, one source said.

The USS Powhatan was in the "immediate area," Icenogle said, adding, "It could render some assistance."

President Reagan, who learned of the fire Saturday in a message from Soviet leader Mikhail Gorbachev, offered the U.S. government's assistance, but the White House said yesterday that the Soviets have not asked for help.

Tass, the official Soviet news agency, reported that fire broke out on the sub 620 miles northeast of Bermuda. The announcement said three people were killed but there was no danger of nuclear explosion or radiation contamination.

The Pentagon official said it appeared most of the crew on the sub, which normally carries 120 people, had been moved.

"We know they have taken a lot of them off, but we don't have a precise number," the source said.

Vintage 1960s

The ship is a Yankee-class sub-marine, which according to the Jane's Fighting Ships, is an old-class submarine that first appeared in the mid-1960s, capable of carrying 16 missiles. Each ship has two nuclear reactors to drive two steam turbines.

Secretary of State George Shultz, appearing on ABC's "This Week with David Brinkley," said that the information received from U.S. planes flying overhead indicates that "there's no additional radioactivity in the atmosphere."