Five Big Law firms have entered appearances for the world’s three largest asset managers accused of colluding in an environmental, social and governance scheme to reduce coal output in violation of federal antitrust statutes.

Gibson, Dunn & Crutcher and Wilmer Cutler Pickering Hale and Dorr represent BlackRock Inc.; Covington & Burling and Troutman Pepper Locke represent Vanguard Group Inc.; and Vinson & Elkins represents State Street Corp. in the antitrust lawsuit filed by 11 conservative state attorneys general.