BP will pay a $4 billion penalty and plead guilty to felony misconduct in the Deepwater Horizon disaster that caused the worst offshore oil spill in the country’s history, the company said on Thursday.

The company will also pay $525 million to settle securities claims with U.S. regulators. In aggregate BP said it will pay $4.5 billion over six years for the various resolutions.

BP’s penalties for the April, 2010, explosion on the Deepwater Horizon rig in the Gulf of Mexico in which 11 workers died, and subsequent leak from the Macondo oil well, will far exceed the previous record for largest criminal penalty in U.S. history.

That record was held by pharmaceutical company Pfizer Inc, which paid a $1.3 billion fine in 2009 for marketing fraud.

BP, which replaced its chief executive after the spill as its market value plummeted, still faces economic and environmental damage claims sought by four Gulf Coast states and other private plaintiffs.

The mile-deep Macondo well spewed 4.9 million barrels of oil into the Gulf over 87 days, fouling shorelines from Texas to Florida and eclipsing in severity the 1989 Exxon Valdez spill in Alaska.

BP has been negotiating for months with the U.S. government and Gulf Coast states to settle billions of dollars of potential civil and criminal liability claims.

A deal could resolve a significant share of the liability the oil company faces, but is not the “global” deal to resolve all outstanding civil and criminal liability with the U.S. government and Gulf Coast states.

BP’s U.S. shares were up about 1.3 percent on Thursday while its London-traded shares were 0.3 percent higher.