BP is set to receive a record fine of between $3bn and $5bn (£1.9bn-£3.2bn) to settle criminal charges related to the 2010 Deepwater Horizon disaster, the BBC has learnt.
It will be the biggest criminal penalty in US history, BBC business editor Robert Peston says.
The settlement with the Department of Justice involves BP pleading guilty to criminal charges.
It is thought that up to four BP staff may be arrested, Robert Peston says.
Details of the settlement are expected to be confirmed by the Washington-based Department of Justice later.
Earlier, BP said it was in “advanced discussions” with US agencies about settling criminal and other claims.
BP said that any deal would not include a range of other claims including individual and federal claims for damages under the Clean Water Act, and state claims for economic loss.
The 2010 Deepwater Horizon disaster killed 11 workers and released millions of barrels of crude into the Gulf of Mexico over 87 days.
The settlement is much bigger than the largest previous corporate criminal penalty assessed by the Department of Justice, the $1.2bn fine imposed on drug maker Pfizer in 2009.
The oil giant has been selling assets worth billions of pounds to raise money to settle all claims. The company is expected to make a final payment of $860m into the $20bn Gulf of Mexico compensation fund by the end of the year.
BP has booked provisions of $38.1bn to cover its liabilities from the incident, but the company has said the final cost remained highly uncertain.