Transocean Ltd has agreed to pay $1.4bn to settle US government charges arising from the massive 2010 BP Plc oil spill in the Gulf of Mexico, a source familiar with the matter said today.
The settlement includes $1bn in civil penalties and $400m in criminal penalties the source said.
Transocean did not immediately respond to a request for a comment.
Transocean owned the Deepwater Horizon rig that was drilling a 1.6km-deep well when a surge of methane gas sparked an explosion on 20 April 2010.
The explosion killed 11 men and led to one of the largest environmental disasters in US history.
BP and Transocean had "multiple safety management system deficiencies that contributed to the Macondo incident," and neither had adequate safety rules, according to a July 2012 report from the US Chemical Safety Board.
Transocean and BP disagreed on who was in charge of interpreting what is known as a negative pressure test, which could have alerted workers to the well's instability.
BP in November agreed to a settlement with the US government worth $4.5bn, including the largest criminal fine ever at $1.256bn.
The London-based giant oil company also agreed to plead guilty to obstruction of Congress, a felony.
As of 30 September, Transocean had set aside an estimated $1.9bn for losses related to the Deepwater Horizon.