A Louisiana federal court lambasted BP for the massive 2010 oil spill in the U.S. Gulf Coast on Thursday, saying the incident was a combination of "gross negligence" and "reckless" conduct by the oil giant and other oil producers — a judgement the company strongly rejected.

In a sharply worded ruling, the British oil company, Offshore Deepwater Drilling and Halliburton are "each liable under general maritime law for the blowout, explosion and oil spill," but Europe's second largest oil company shoulders the overwhelming part of the blame, the U.S. District Court for the Eastern District of Louisiana determined.

The dense, 153-page decision argued BP ignored early signs that the well was on the verge of a catastrophe. The decision set the stage for substantially higher fines that could potentially cost BP more than vast sums it has already set aside.

The blowout at BP's Macondo well four years ago killed more than 10 people, spewing vast amounts of oil into the Gulf of Mexico and transfixing the nation for weeks. Years later, the company has grappled with the fallout for years as it attempts to limit its liability in the court while rebuilding trust among investors and the general public.



For its part, BP pushed back against the court's assertion of gross negligence. In a stern statement of its own, the company vowed to appeal, saying that the finding "is not supported by the evidence at trial. The law is clear that proving gross negligence is a very high bar that was not met in this case."

The company added that "an impartial view of the record does not support the erroneous conclusion reached by the District Court. BP is reviewing the decision and will issue a further statement as soon as possible."

Travis Nichols, a spokesperson for environmental advocacy group Greenpeace, lauded the decision in an interview with CNBC. "It's good news for those directly affected by this disaster. Hopefully will make other companies like Chevron and Exxon think twice about their drilling," he said.