BP Plc is hoping to reach an agreement with U.S. authorities which would require it to pay under $15 billion to settle all criminal and civil penalties arising from the 2010 Deepwater Horizon disaster, the Financial Times reported, citing a person familiar with the matter.

The amount is less than the $20 to $25 billion the Department of Justice is seeking from the company.

Negotiations between the DoJ and BP are accelerating and an agreement could be reached before the Democratic party's convention in September, the FT quoted the person as saying.

Eleven people were killed in the explosion on April 20, 2010, and 4.9 million barrels of oil spewed from the mile-deep well in by far the worst offshore U.S. oil spill.

The oil giant still faces claims by the U.S. government, which is pursuing violations of the Clean Water Act and other laws, which could result in fines totaling billions of dollars.

BP also faces claims from Gulf states as well as its drilling partners.

The company and the DoJ were not immediately available for comment outside normal business hours.