Exxon Corp., responding to a judge's decision to reject a $100 million fine against the company, said it was gearing up to defend itself in a possible criminal trial in the nation's worst oil spill.

The giant oil company, however, could avoid a trial by entering a new plea or trying to negotiate a new criminal fine.Meanwhile Thursday, Alaska legislators, environmentalists and others weighed the implications of U.S. District Judge H. Russel Holland's stunning ruling the day before that the fine was too low.

"It's one of the most important environmental court decisions of the last century," declared Walter Parker, chairman of the Alaska Oil Spill Commission, which investigated the wreck of the Exxon Valdez and issued a report blaming the oil industry and government complacency for the March 1989 spill.

Parker characterized the judge's ruling as a clear message that the oil industry must do more to transport oil safely and that failure to do so will be painful.

The $100 million criminal fine - agreed to under a plea-bargain with federal prosecutors - and a separate still-pending $900 million civil damage settlement have both come under heavy criticism by many who feel Exxon is getting off easy.

The fine would have set a record for environmental crimes.

Coincidentally, Exxon Wednesday reported that its first-quarter earnings were up 75 percent to $2.24 billion.

Those earnings for just the first three months of the year represent what the oil giant has spent in two years to clean up the spill in Prince William Sound. A third cleanup season is about to begin.

In the wake of Holland's ruling, Lloyd Miller, a lawyer suing Exxon on behalf of the food-gathering Aleuts, suggested Exxon Chairman Lawrence Rawl should "think again about making remarks that it (any fine) won't affect the bottom line."

Rawl had said the proposed settlement "will not have a noticeable effect on our financial results."

In its first official reaction Thursday to Holland's sharp rebuke, Exxon issued a two-sentence statement saying, "Recognizing the substantial costs already incurred by Exxon and the additional payments included in the agreements we entered into with the federal and state governments, we believed that the agreements were appropriate."