The U.S. Supreme Court rejected appeals from BP Plc and Anadarko Petroleum Corp., leaving intact a ruling that opens the companies to potentially billions of dollars in fines for the 2010 Gulf of Mexico oil spill, Bloomberg said June 29.

The federal government is seeking as much as $13.7 billion in civil fines from BP and more than $1 billion from Anadarko. The offshore spill, caused by the explosion of BP’s Deepwater Horizon oil rig, was the largest in U.S. history, releasing millions of barrels of oil into the Gulf.

U.S. District Judge Carl Barbier in New Orleans could say any day what fine he will impose on BP and Anadarko. Supreme Court intervention might have delayed that ruling.

An earlier order by Barbier was at issue in the Supreme Court appeal. A federal appeals court last year upheld the judge’s conclusion that BP and Anadarko were automatically liable as co-owners of the well.

Barbier later ruled that BP was grossly negligent, subjecting the London-based oil company to larger penalties under the Clean Water Act.

The BP fine sought by the government would be a record under the Clean Water Act.

The cases are Anadarko Petroleum v. United States, 14-1167, and BP Exploration v. United States, 14-1217.