BP said the U.S. Department of Justice has backed its claim that oil it recovered at the 2010 spill site should be excluded from certain penalties it could face, potentially cutting its final fine by as much as $3.5 billion.
Just days before its civil trial is due to start on February 25 in New Orleans, the British oil company repeated its assertion that some 810,000 barrels of oil it recovered directly from the leaking Macondo well should not count when it comes to fines that could be levied under the U.S. Clean Water Act.
"Under the Clean Water Act, civil penalties are assessed only on oil that has actually entered the environment and potentially caused harm," it said in a statement on Tuesday.
"The U.S. Department of Justice has indicated that it agrees with BP's position on this issue," it added.
BP also repeated that the total 4.9 million spilt barrels estimate made by the U.S. government in its claim against BP, including barrels recovered, was too high by 20 percent.
The over-estimate, together with removal of the recovered barrels, would reduce the per-barrel basis of the U.S. government claim to 3.1 million barrels.
The maximum fine payable under the act is $4,300 per barrel, and so if the calculation is based on 4.9 million barrels spilt, BP could have to pay as much as $21 billion under the Clean Water Act, on top of any other fines and penalties that might be payable.
If the number spilled is only 3.1 million, as BP asserts, the maximum fine would be much lower at around $13 billion.
(Reporting by Andrew Callus; Editing by Hans-Juergen Peters)