Washington-based lobbying and law firm Patton Boggs will pay Chevron US$15 million in relation to the former’s role in a lawsuit against the company in Ecuador.

The lawsuit dates back to 2003 when a group of Ecuadorean villagers sued Chevron for alleged contamination of water and soil done by Texaco, which Chevron bought in 2001.

After years of litigation, an Ecuadorean judge ruled in 2011 against Chevron and awarded villagers US$18 billion, though an Ecuadorean higher court later reduced it to US$9.5 billion.

But Chevron successfully countersued, with a March US District Court decision barring the plaintiffs, represented by New York lawyer Steven Donziger, from enforcing the judgment in the United States.

Patton Boggs had worked with Mr Donziger and the Lago Agrio plaintiffs since early 2010, as well as filing three separate lawsuits on its own behalf in the United States against Chevron.

Chevron won an application in March to pursue Patton Boggs with counterclaims relating to its role in connection with the Ecuadorian action and related litigations against the company.

The settlement has resolved those claims, with Patton Boggs withdrawing from the Ecuador litigation, issuing a statement of regret and assigning its interests in the litigation to Chevron, as well as making the payment.

Chevron general counsel Hewitt Pate said the agreement brought the counterclaim to an end.

“In settling this matter, Patton Boggs is the latest party, among many others, to disassociate itself from Steven Donziger and the Lago Agrio Plaintiffs,” Chevron said in an announcement.