Washington - The US Supreme Court on Wednesday absolved ExxonMobil of paying an extra 2.5 billion dollars in damages for a massive oil spill nearly two decades ago off the coast of Alaska.

In a near-unanimous decision, the highest US court limited punitive damages to 507.5 million dollars, which the energy giant has already given to affected residents as part of a wider 3.5-billion- dollar pay out.

The Exxon Valdez tanker devastated the shores of southern Alaska in 1989, costing thousands of fisherman and businesses in the region their livelihood.

The Supreme Court case revolved around whether ExxonMobil should be held responsible for the mistakes of the ship's captain, who it was later discovered was a relapsed alcoholic who may have been drinking on the night of the accident. (dpa)