BP Plc is expected to plead guilty to criminal misconduct in the 2010 Deepwater Horizon disaster under a plea deal with the Justice Department that could be announced as soon as Thursday, two sources familiar with discussions tell Reuters.

The sources, who spoke on condition of anonymity, said BP will plead guilty in exchange for a waiver of future prosecution on the charges. BP and the U.S. Justice Department declined to comment.

BP has been in months-long negotiations with the federal government and Gulf Coast states to settle billions of dollars of civil and criminal liability claims resulting from the April 20, 2010, explosion aboard the Deepwater Horizon rig that killed 11 workers and fouled the shorelines of four Gulf Coast states in the worst offshore spill in U.S. history.

It is unclear what form of criminal misconduct BP will admit. In an August filing, the Department of Justice said "reckless management" of the Macondo well "constituted gross negligence and willful misconduct," which it intended to prove at a civil trial set to begin in New Orleans in February 2013.

It is also unclear whether the deal will resolve any civil charges brought by the Justice Department, and how large a financial penalty BP might pay to resolve them.

BP has previously adamantly denied any suggestion that it was grossly negligent in the disaster, a charge that could trigger billions of dollars in penalties under the Clean Water Act.