LOS ANGELES - A federal appeals court on Monday ordered Exxon Mobil Corp to pay $507.5 million in punitive damages stemming from the 1989 Exxon Valdez oil spill off Alaska, plus 5.9 percent interest running from the 1996 trial judgment, the opinion said.

The amount is a fraction of the $5 billion in punitive damages originally awarded to fishermen, Alaska natives, business owners and other litigants by a jury in 1996, and equals the compensatory damages agreed to in a subsequent settlement, the opinion said.

The opinion issued on Monday by the Ninth U.S. Circuit Court of Appeals set the punitive damages figure, and determined the date from which the interest would run, after the U.S. Supreme Court ruled that the maximum ratio of punitive to compensatory damages is 1:1 under maritime law.

In a split decision, the appeals court ordered each party to bear its own attorney fees and court costs.

Attorneys for the plaintiffs could not be reached immediately for comment. An Exxon spokesman had no immediate comment.

The oil spill from the Exxon Valdez supertanker in 1989 was the worst in the nation's history, blackening more than 1,200 miles of Alaska's coastline.

The clean-up alone cost around $2.5 billion.

The case is In Re: The Exxon Valdez, No. 04-35182, U.S. Court of Appeals for the Ninth Circuit.

(Reporting by Gina Keating in Los Angeles; Editing by Gary Hill)

Oil Spill