A 644-foot oil tanker loaded with 300,000 barrels of crude oil lost power and began taking on water yesterday off the North Carolina coast, and was riding with her deck just three feet above water.

Divers sent to the Esso Portland worked to repair a faulty 24-inch valve that apparently was letting water into the ship's hold.

The Coast Guard's special strike team, trained to cope with oil spills and cleanups, reached the ship about 3:30 p.m. with pumps in an effort to keep the tanker afloat and avoid an oil spill.

Coast Guard spokesman George Stuart said last night the tanker had stabilized and said that if the divers repaired the valve, work could begin to pump the water out of the vessel.

"If they can pump it out -- unless we have bad weather -- they should be able to save the ship" and avert an oil spill, Stuart said. There was "no oil as yet in the water," he said.

Stuart had said earlier that any oil spilled from the ship would hit North Carolina beaches.

The ship is of Liberian registry and was en route to Wilmington, N.C. It has a cargo of 100,000 barrels of No. 5 crude and 200,000 barrels of No. 6 crude, the Coast Guard said.