Transocean Ltd. and the Justice Department have discussed a $1.5 billion settlement that would resolve federal civil and criminal claims against the company over its role in the deadly 2010 rig explosion that spawned the nation's worst offshore oil spill.
But Switzerland-based Transocean Ltd. said in a regulatory filing Monday that a "number of issues," including the possible time period for payment, must be resolved before a deal can be completed.
A Justice Department spokesman declined to comment.
Transocean owned the Deepwater Horizon drilling rig, where 11 workers died in an April 2010 explosion triggered by a blowout of BP's Macondo well.
Transocean also says it rejected settlement offers earlier this year from BP and a group of private attorneys for Gulf Coast residents and businesses.