File photo.

A judge on Thursday accepted drilling rig operator Transocean Ltd's agreement to plead guilty to violating the Clean Water Act and pay $400 million to settle US government criminal charges over the massive Gulf of Mexico oil spill at BP Plc's Macondo well in 2010.

The overall settlement, unveiled last month by the US Department of Justice, included $1 billion in civil penalties in addition to the $400 million in criminal penalties. - Reuters