It's a rare set of statistics that doesn't work to somebody's advantage, and the government's sharply lower estimate of offshore oil resources is a case in point.

The Interior Department's recent analysis lowered official expectations for offshore oil by 55 percent, from 27 billion barrels to 12.2 billion. That was cause for considerable gloom in some quarters -- not the least the oil industry, which likes to defend its tax breaks by holding out the tantalizing prospect of vast pools of petroleum out there for the drilling.

But the news didn't faze the Energy Department, where the figures quickly found a niche in the administration's repertoire of arguments for heavier emphasis on coal-fired and nuclear power plants.

"I saw the figures. I think they're probably pretty accurate," said Energy Secretary John S. Herrington. "You can't get away from the conclusion that there's less oil than we thought there was, and that has long-range implications for the country."

The new estimates couldn't have come at a better time for Herrington, who stressed coal and nuclear power in his first major policy speech before the American Power Conference last month in Chicago and has been repeating the message ever since.

"We cannot be oblivious to the fact that despite the price rises of the last decade, the supply of American oil has not risen significantly," he told utility executives in Chicago.

The offshore oil estimates came as no particular surprise to DOE officials, or to Interior officials either, for that matter. In the last few years, federal lease offerings in once-promising offshore areas have gone begging for bidders. Interior and oil executives say a soft oil market is the main reason for lagging sales, but they acknowledge that disappointing exploration has dampened enthusiasm as well.

"We usually have 4,800 drilling rigs working offshore," Herrington said in an interview last week. "Today we have 1,830 rigs. The fact is, we're not finding as much oil and gas and there's not as much activity looking for those . . . . "

That kind of argument worries Interior policy-makers, who are trying to persuade a skeptical Congress that aggressive leasing is the best way to forestall a future energy crunch. But it plays nicely at DOE, which has been under attack for its emphasis on nuclear and coal technologies at the expense of alternative forms of energy production.

"Our budget is heavily into coal R&D and nuclear, and I believe it should be in those two areas," Herrington said. "We must learn how to use nuclear power safely. We must learn how to burn coal cleanly. We have those two sources of energy and the third is conservation and efficiency. Our energy future is with those three."