The U.S. government in 2010 sued Transocean, saying it violated federal pollution laws because of the 2010 oil spill in the Gulf of Mexico.
In 2010, an explosion on the Deepwater Horizon rig killed 11 rig workers and led to one of the worst offshore oil disasters.
An audit by the U.S. Chemical Safety Board said companies such as BP, the rig operator, and Transocean focused more on issues that could lead to a work slowdown more than on the factors that may have contributed to the spill.
Transocean said in a regulatory filing cited by Bloomberg News that it's been unable to reach an agreement on claims from the spill.
"There are a number of issues that the parties would need to resolve in order to reach any settlement," the filing stated.
The company said it has $2 billion reserved for claims related to the spill. Transocean said it was reviewing language from the Oil Pollution Act of 1990 that requires reimbursement to the government for costs associated with restoring sites to pre-existing conditions.