BP Plc asked a federal appeals court in New Orleans to review a trial judge’s ruling that 3.19 million barrels of oil gushed into the Gulf of Mexico from the company’s blown-out well in 2010.

The size of the spill, coupled with an earlier ruling that BP acted with gross negligence in drilling the well, exposes the London-based company to as much as $13.7 billion in pollution fines under the U.S. Clean Water Act.

U.S. District Judge Carl Barbier issued his rulings after concluding two phases of a multistage trial over BP’s conduct before and after the spill. A ruling in a third phase, which involves factors that must be considered in setting BP’s pollution fine, isn’t expected until after final court filings are submitted in late April.

On Friday, the U.S. asked the appeals court to prevent BP from filing piecemeal appeals of each stage of Barbier’s ruling, as the company has done with appeals of individual rulings involving aspects of its civil settlement over spill damages. The government asked the appellate court to wait to consider Barbier’s rulings from all phases of the liability trial together after the judge determines BP’s final fine.