The only known survivor from a ferry that crashed into an oil tanker said Thursday he clung to a rail for two hours because the water below was covered by a huge sheet of flame. At least 139 people were missing and feared dead in the disaster.

"I heard screams from the passengers and other crew members, but there was nothing I could do," said the survivor, cabin boy Alessio Bertrand."Flames erupted and smoke was everywhere, we couldn't see anything," Bertrand, 23, said by telephone hours after the disaster Wednesday night.

He said he and two other men fought their way to a door in the dark and got outside "but we couldn't jump off because oil was burning in the sea." He said the other two men died from the smoke that quickly covered the ferry.

"I hung on, I don't know how, for about two hours. Then the coast guard came and told me to jump off. I don't know why I'm here and the others are all dead, it's a miracle," he said from his hospital bed.

An attending physician said Bertrand appeared to be in good condition but was still in shock. "There are no obvious signs of injury, but he's very stressed," he said.

The ferry hit the back of the tanker on its right side in thick nighttime fog, opening a wide hole and spilling crude oil into the Ligurian Sea off northwestern Italy.

Authorities held out little hope of finding more survivors. By midday Thursday, two bodies had been recovered, search teams said.

The tanker, at anchor 21/2 miles offshore, also caught fire after the 10:30 p.m. collision, but all 28 of its crew members were reported safe.

Port officials said the tanker's crew jumped into lifeboats after fighting the flames without success.

Civil Defense and port authorities said 72 passengers and 67 crew members of the 6,187-ton Moby Prince ferry were missing. All were believed to be Italian.

The ferry had been bound for Olbia, Sardinia, when it hit the tanker, the AGIP Abruzzo, port authority chief Sergio Albanese told state-run RAI-TV. The tanker is owned by the Italian oil company AGIP.

While about 100 relatives of passengers kept up a vigil outside shipping offices, the charred shell of the ferry was towed through the main harbor and then back out for fear it would sink.

Initial fears of an environmental disaster lessened when authorities reported that only one tank aboard the AGIP Abruzzo had ruptured.

Alessandro Pierangeli, a government official, said the tanker carried about 550,000 barrels of crude but that only 16,000 barrels had leaked out and much of that burned off or evaporated.