NEW ORLEANS — BP said today that it will pay $4.5 billion in a settlement with the U.S. government over the massive 2010 oil spill and will plead guilty to felony counts related to the deaths of 11 workers and lying to Congress.

The figure includes nearly $1.3 billion in criminal fines — the largest such penalty ever — along with payments to several government entities.

A person familiar with the settlement said two BP employees will also face manslaughter charges over the deaths of 11 people in the explosion of the Deepwater Horizon oil rig that triggered the massive spill.

“We believe this resolution is in the best interest of BP and its shareholders,” said Carl-Henric Svanberg, BP’s Chairman. “It removes two significant legal risks and allows us to vigorously defend the company against the remaining civil claims.”