NEW ORLEANS — BP said Thursday 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. The person was not authorized to discuss the matter on the record and spoke on condition of anonymity.

The settlement includes payments of nearly $2.4 billion to the National Fish and Wildlife Foundation, $350 million to the National Academy of Sciences and about $500 million to the Securities and Exchange Commission.