Transocean acknowledged that its description of 2010 as its "best year in safety" despite a blowout that sank one of its rigs, killing 11 workers and causing a huge oil spill, might be insensitive.

A boat works uses a protective boom to collect oil that has leaked from the Deepwater Horizon wellhead in the Gulf of Mexico.

In a filing with U.S. financial regulators on Friday, Transocean had said it achieved an "exemplary" safety record last year as measured by its total recordable incident rate and total potential severity rate.