“BP is in ongoing discussions with the DOJ [Justice Department] and other federal agencies regarding a possible settlement of these claims and whilst it is ready to settle on reasonable terms, a number of unresolved issues remain and there is significant uncertainty as to whether an agreement will ultimately be reached,” BP said Tuesday in its third-quarter earnings report.

BP could owe as much as $21 billion in Clean Water Act fines alone, on top of potential criminal penalties for gross negligence for the incident that dumped more than 4 million barrels of oil into the Gulf and killed 11 people.

Industry analysts have noted BP’s decision last week to sell its stake in Russian joint venture TNK-BP to a Russian oil firm, Rosneft, freed up cash for a possible settlement.