Failures by BP and other companies led to the Gulf of Mexico oil disaster, the British energy group concluded on Wednesday as it sought to defend itself against possible multi-billion-dollar US lawsuits.

As expected in the findings of its own inquiry, BP did not admit "gross negligence" for the oil rig explosion in late April that killed 11 people and caused the worst ever US environmental disaster.

This still image from a BP video feed shows oil gushing from the oil well-pipe in the early hours of July 5, 2010 in the Gulf of Mexico. Credit:AFP

The report did, however, propose 25 recommendations, including improved staff training, designed to prevent a repeat of the Deepwater Horizon rig disaster.

An explosion on April 20 at the BP-operated rig ruptured a well, causing about 4.9 million barrels of oil to leak into the sea.