In a remarkable capitulation to claims that it backed a fraudulent lawsuit against Chevron Corporation, Patton Boggs agreed Wednesday to pay the oil giant $15 million and to give up its stake in a $9.5 billion environmental judgment. Patton Boggs’ erstwhile cocounsel, Steven Donziger, quickly lashed out at the deal, calling it a betrayal of the Ecuadorean villagers they jointly represented.

Patton Boggs disclosed the $15 million payment to Chevron in a 22-page settlement agreement, which will be filed with the federal judge in Manhattan overseeing Chevron’s fraud case against the firm. As part of the agreement, Patton Boggs will withdraw from representing the Ecuadorean plaintiffs, and will assign to Chevron any money the firm would be entitled to from that representation, which could in theory reach $475 million. The firm also agreed to assist Chevron with discovery and to make two of its partners, James Tyrrell Jr. and Eric Westenberger, available for depositions.