A U.S. oil company that owned a 25 percent stake in the Gulf of Mexico oil well that exploded last year has agreed to pay $4 billion to victims of the worst American oil spill.

Anadarko Petroleum had been feuding with BP, the oil well’s operator, over who was responsible for the explosion that killed 11 workers and sent five million barrels of oil pouring into the waters off the southern coast of the United States.

But BP announced a settlement of the dispute Monday, and said it would put Anadarko’s money into the $20 billion trust it created to pay damage claims from businesses and individuals affected by the April 2010 incident.

BP Chief Executive Robert Dudley said there is “clear progress” in corporations taking responsibility for the disaster. Now, he said it is time for two other contractors that worked on the well, Switzerland’s Transocean and the U.S.-based Halliburton, to also settle damage claims.

Transocean operated the rig, while Halliburton was responsible for the cement work.