BP has for the first time admitted that it made mistakes, which led to the Gulf of Mexico oil spill, according to US reports

BP accepts Fault for oil spill, three months later

BP has for the first time admitted that it made mistakes, which led to the Gulf of Mexico oil spill, according to US reports.

The oil giant's internal investigation found that managers misinterpreted data that told them a blowout was imminent on the very day the disaster happened.

Hours later the Deepwater Horizon oil rig exploded, killing 11 men and causing the worst environmental disaster in US history.

BP has long avoided shouldering the blame for the accident, as it grapples with the legal and financial fallout.

Study results
Now, its own internal probe, which it began immediately after the spill began, found that on April 20
managers misread pressure data and gave their approval for rig workers to replace drilling fluid in the well with seawater.

The seawater was not heavy enough to prevent gas that had been leaking into the well from firing up the pipe to the rig, causing the explosion.

The investigation has also asked why John Guide, an engineer with BP and the team leader overseeing the project, ignored warnings about weaknesses in cement outside the well, which could have prevented the gas from escaping. BP intends to release details of the 200-page report in the next week or so.

It was led by Mark Bly, its head of safety and operations and involved interviews with staff ranging from engineers up to vice presidents and a review of internal documents.

The conclusion was that BP was partly to blame, as was Transocean, which owned the rig.

BP faces a string of other probes by US authorities including the US Justice Department and several Congressional Committees.

Under pressure
Since the spill happened, BP has vowed to take full responsibility for the clean-up after coming under pressure from the Obama administration to do so.

The company has been forced to suspend dividends as its value plunged by more than half.

Beleaguered chiefu00a0 executive Tony Hayward has also been forced to hand in his resignation after a string of gaffes.

BP has refused to comment on the leaked memo.