The loss compared with a net profit of 368 million dollars posted in the third quarter in 2010.

Transocean owned the Deepwater Horizon rig, leased by British energy giant BP, which exploded on April 20, 2010, killing 11 workers and causing millions of gallons of oil to pour into the Gulf of Mexico.

BP has sued Transocean for damages of $40 billion (27 billion euros) over the disaster and Transocean in turn, has counter-sued.

In April, the US Coast Guard slammed Transocean's "poor safety culture" in a report.