HOUSTON (Reuters) - It may be months before a final verdict is issued on the size of the fine BP Plc will pay under the Clean Water Act for its 2010 Gulf of Mexico oil spill, lawyers said on Tuesday after the last phase of the trial ended.
U.S. District Court Judge Carl Barbier in New Orleans, Louisiana, is scheduled to receive post-trial briefs from government prosecutors and BP through April 24.
Barbier might rule before then although a decision after all briefs are filed is more likely, the lawyers said.
In arguments that wrapped up on Monday, BP tried to whittle away at $13.7 billion in potential fines if faces under the Clean Water Act for the worst offshore disaster in U.S. history.
BP has said its fine should be modest as it took extensive steps to mitigate the disaster and that the defendant named in the case, BP's exploration and production unit, known as BPXP, cannot afford a big penalty.
BP also said a drop of more than 50 percent in oil prices since June has slashed BPXP's value.
The government urged a fine at or near the maximum.
Clean Water Act rules say when assigning penalties the court must look at BP's ability to pay, steps it took to clean up the spill, and its history of past violations, among other factors.
The Clean Water Act penalties would come on top of more than $42 billion the oil major has set aside for cleanup, compensation and fines. About 810,000 barrels were collected during cleanup.
Several billion dollars in potential fines were avoided in January when Barbier put the size of the spill at 3.19 million barrels. That was well below the government's estimate of 4.09 million barrels, which could have led to $17.6 billion in fines.
All three phases of the trial, over the degree of negligence, the size of the spill, and the size of the fine, have now concluded.
Under a "gross negligence" ruling Barbier issued in September, BP could be fined a statutory limit of $4,300 for each barrel spilled, though he has authority to set lower penalties.
BP has also filed motions saying the maximum fine per barrel is in fact just $3,000 because Congress never passed laws to adjust it for inflation.
A simple "negligence" ruling, which BP sought, caps the maximum fine at $1,100 per barrel.