CIUDAD DEL CARMEN, Mexico (AP) _ Rescue ships and helicopters searched the southern Gulf of Mexico on Sunday for 33 crew members and workers missing after a boat carrying oil drilling equipment sank off the Mexican coast.

No survivors had been found by early afternoon, according to a statement from the government oil company, Pemex.

It said 30 ships, aided by helicopters, searched the area off the southeastern state of Campeche for survivors of the vessel Huichol, which sank Saturday morning in high winds.

Sixty-nine crew members and two Pemex workers were aboard the ship when the accident occurred 36 miles northeast of Ciudad del Carmen, which is approximately 630 miles southeast of Mexico City.

Thirty-seven crew members and one oil company employee were rescued within hours of the accident, it said. None required hospitalization.

Authorities had said Saturday that they believed there were additional survivors in lifeboats. But the latest Pemex statement made no mention of that possibility.

The boat, owned by the private firm, Condux, S.A., contained specialized equipment for maintaining the huge oil drilling platforms Pemex operates in the gulf and for searching for new oil deposits.

The country's major oil fields are offshore in the Bay of Campeche, which is in the southern part of the gulf.

The Pemex statement said drilling on the platforms was proceeding normally.

Mexico is the world's fourth largest producer of crude oil and the single biggest supplier to the United States.

Sales of its oil to foreign buyers are the No. 1 source of foreign revenues to pay the country's foreign debt of $96.4 billion and buy food and needed imports.