The U.S. Supreme Court on Tuesday declined to decide whether Exxon Mobil Corp. must pay interest on punitive damages awarded in the nation's worst oil spill.

In a brief order, the court said the 9th U.S. Circuit Court of Appeals, based in San Francisco, should decide the matter of interest arising from punitive damages for victims in the 1989 Exxon Valdez disaster.

Stanford University law professor Jeffrey Fisher, an attorney who represents commercial fishermen, Native Alaskans, landowners, businesses and local governments in the case, said justices rejected Exxon Mobil's bold attempt to take away interest.

"It's nice to see the court refusing to do the outlandish thing Exxon wanted," Fisher said.

The issue is whether interest accrued since 1994, when a federal jury first awarded punitive damages for the supertanker's spill of 11 million gallons of crude oil into Alaska's Prince William Sound.

The company contends that if interest is paid, it should be calculated from the date the punitive damages were awarded by the Supreme Court, not all the way back to 1994, said Exxon Mobil spokesman Alan Jeffers. The company will pursue that contention with the 9th Circuit.