Oil major BP has reached an additional $1 billion settlement agreement for claims from local US government entities regarding the Gulf of Mexico oil spill, bringing the total bill to $54.6 billion, it said on Tuesday. "As part of the agreements in principle, BP agreed to pay up to $1 billion to resolve claims made by local government entities," the company said in its second-quarter results update, Reuters reported. On July 2, the oil company reached a milestone $18.7 billion settlement with the US government and five states to resolve claims from the deadly 2010 Macondo oil spill. The spill was sparked by a blast on the Deepwater Horizon rig, which killed 11 men and sent millions of barrels of oil flowing into waters, in one of the worst environmental disasters to strike the US.