Story highlights

Judge accepts agreement between Transocean and prosecutors on oil spill fines

Transocean will have two years to pay the $1 billion fine

Transocean pleaded guilty last week to criminal violations of the Clean Water Act

A separate civil trial begins next week to determine the cause of the accident

Transocean Deepwater Inc. will pay $1 billion in civil penalties for the 2010 oil spill in the Gulf of Mexico, after a federal judge in New Orleans signed off Tuesday on the company’s deal with the Justice Department.

The ruling by U.S. District Judge Carl Barbier is a formality: the Justice Department and Transocean reached the deal last month.

Under the agreement, Transocean will have two years to pay out the $1 billion in fines for violations of the Clean Water Act.

According to the Justice Department, the agreement also requires Transocean to take steps to improve performance and avoid a repeat of the disaster, which began after the Deepwater Horizon oil rig exploded nearly a mile above BP’s sea-floor Macanado well, killing 11 workers on board.

The blast and ensuing fire damaged the rig and caused 4.9 million barrels of oil to leak out into the Gulf, according to a 2011 report by the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling.

In addition to the civil penalties, Transocean Deepwater pleaded guilty last week to a criminal violation of the Clean Water Act. U.S. District Judge Jane Triche Milazzo ordered the company to pay a $400 million fine, the second-largest such penalty in U.S. history.

The largest was the $4 billion fine imposed on BP in November after the company agreed to plead guilty to felony manslaughter, environmental crimes and obstruction of Congress related to its role in the Deepwater Horizon spill.

BP contracted Transocean to do the drilling and had BP officials on the rig. At the time, prosecutors said BP had a “culture of privileging profit over prudence.”

Much of the $400 million Transocean fine will be used to restore and rebuild the Gulf coast region, officials have said.

A separate civil trial over the spill is set to begin Monday. That suit, filed by a large group of states, individuals, businesses and the federal government, seeks compensation from BP, Transocean, Halliburton and other companies involved in the disaster for damages incurred from the spill. The trial seeks to determine the cause of the incident and how much each company should pay.

Barbier will also preside over that trial.

In a statement issued Tuesday, BP said the demands made by plaintiffs are “excessive and not based on reality.” The company will “vigorously defend against gross negligence allegations,” BP general counsel Rupert Bondy said.

“This was a tragic accident, resulting from multiple causes and involving multiple parties,” he said. “We firmly believe we were not grossly negligent.”

Transocean spokesman Lou Colasuonno said Tuesday that company is also ready for trial.

“The facts of the case are on Transocean’s side and our legal team is fully prepared to start proving that New Orleans next week,” he said.

CNN’s Vivian Kuo contributed to this report.