The British government has urged the US Supreme Court to review appeals court rulings against BP over the 2010 Deepwater Horizon oil spill on the coast.

In a friend of court brief, the UK said lower court rulings raise grave international concerns by undermining confidence in the "vigorous and fair resolution of disputes."

After going to "great lengths to restore the US Gulf Coast," BP is now being required to pay large sums to others who were not injured by the spill, the letter said.

The London-based oil and petrochemicals group is appealing lower court decisions within the past year that it believes wrongly require it to compensate claimants who suffered no injuries from the spill.

The British government said treatment meted out to BP undermined the fairness and trust necessary for international commerce.

The US and Britain conduct more than $200 billion in trade each year, and UK businesses are responsible for 17% of all foreign direct investment in the United States, according to the filing.

In a separate statement, BP said its government's petition emphasizes the importance of fair and consistent application of law.

BP argues that the fifth circuit federal court's decisions, if allowed to stand, will fundamentally alter class action law and discourage companies from settling complex cases.

It also said the decisions will likely discourage companies from investing in the US if they are exposed to liability for losses they did not cause.

Days earlier, a Louisiana court had ruled that BP was "grossly negligent" and "reckless" in the spill, a move that could add nearly $18 billion in fines to more than $42 billion in charges.