A Soviet submarine apparently collided with a Soviet merchant ship in the Strait of Gibraltar yesterday and is steaming slowly on the surface with a badly damaged bow, according to intelligence reports reaching U.S. officials.

The collision, which left the merchant ship in distress and possibly sinking, was one of two or three unrelated incidents involving submarines around the world yesterday, they said.

In another, a U.S. nuclear attack submarine ran into a Navy barge off the coast of Norfolk, Va., suffering minor damage.

In a third, Japanese military officials reported spotting a second Soviet submarine in distress and possibly on fire in the Sea of Japan. U.S. officials could not confirm the report and said the Golf-class submarine may be participating in a military exercise.

The collision involving Soviet ships is the latest of several embarrassing incidents recently for the Soviet submarine fleet. Last March, a Victor-class Soviet submarine collided with the carrier USS Kitty Hawk and, last fall, a similar sub became entangled in U.S. sonar tracking gear and had to be towed to Cuba.

"Their seamanship does not seem to be the greatest," a Pentagon official said.

Any U.S. desire to crow about the latest Soviet misfortunes, however, may be dampened by the incident near Norfolk where the Los Angeles-class submarine Jacksonville collided with a 270-foot Navy barge while steaming on the surface toward port.

Neither vessel was seriously damaged, according to Navy spokesmen in Norfolk, but the Jacksonville sustained "superficial external damage." It continued under its power to Norfolk Naval Station.

Navy officials said that they have not determined who was at fault but that the Jacksonville's running lights were on when the collision occurred about 5 a.m.

In 1982, the Jacksonville sustained $2 million in damage when it ran into a Turkish freighter just outside the Chesapeake Bay.

Details about the incident in the Strait of Gibraltar were sketchy.

Officials said a Victor-class nuclear-powered attack submarine, similar to those involved in the collision with the USS Kitty Hawk and the tracking-gear accident last fall, was east of the strait and moving slowly on the surface with a badly damaged bow.

They said two Soviet navy ships, a frigate and a tender, appeared to be on their way to aid the submarine.

Officials could not identify the merchant ship, which was also near the strait and which they said may be in danger of sinking. They also did not know whether the sub and ship had been traveling together or whether it is a coincidence that the ship struck by the sub also was Soviet.

A Japanese Defense Agency spokesman said in Tokyo that a military plane had flown over a Golf II-class ballistic-missile submarine on the surface of the Sea of Japan off the west coast of the island of Honshu. He said that white smoke was pouring from the submarine and that a Soviet surface ship was seen transferring water to the sub, apparently to put out a fire.

The submarine later submerged, and U.S. officials said they are not convinced that it is in danger. Although they had no immediate explanation about reports of smoke coming from the sub, they apparently had not received information to lead them to believe that the vessel was in trouble.

U.S. Navy officials have maintained that the Soviet submarine fleet is inferior to their own, in its captains' ability and the fleet's technical qualities. A Soviet nuclear sub is believed to have sunk in the North Pacific last summer, and other accidents have been reported.