Bad weather was good news Tuesday for the cleanup of the nation's worst-ever oil spill as a rough sea became a churning caldron that helped break up part of the Exxon Valdez slick.

"It's not proceeding any further," and breaking into tar balls, Coast Guard spokesman Ken Freeze said Tuesday. "That's better than ooey, gooey oil."A light sheen, with a thickness measured in molecules, was spotted at scattered sites inside the Kenai Fjords National Park but posed no serious threat, Freeze said.

Exxon, meanwhile, said it will reimburse the government for the military assistance ordered by President Bush but will write off the cost on its taxes.

"In the normal course of things, cost of doing business is deducted from your income tax and that is how it is expressed to customers," said Don Cornett, the company's top Alaska executive.

The spill has killed thousands of birds and animals, and gasoline prices in the United States have surged in the wake of the disaster.

U.S. Transportation Secretary Samuel Skinner warned oil companies against using the spill as an excuse increase prices.

"If they're doing it, they're making a big mistake," he told reporters in Cincinnati. "I hope the oil industry isn't foolish enough - and I don't think they are, I haven't seen any proof of it - to think they can take advantage of the situation at Valdez to raise prices unnecessarily."

The Coast Guard said Monday the oil had stalled from its southwesterly move toward Kodiak Island, the nation's richest fishing port last year. It said the oil was breaking into tar balls, which sink.

"The weather is breaking up the slick, and that's good," said Coast Guard spokesman Rick Meidt.

In addition, the goop had traveled no further southwest than Gore Point, about 80 miles northeast of Kodiak, in three days.

Officials will have to wait for a break in the weather to see how successful waves and winds were at breaking up the spill.