William J. Stack is a Partner in the firm’s Litigation Department, where he concentrates primarily on environmental litigation and complex trial work.Mr. Stack previously served as Senior Counsel for ExxonMobil Corp., where he worked in the legal department for more than 35 years. He has tried more than 75 matters to verdict since 1984, covering 20 states, including, in addition to New Jersey and Pennsylvania, New Hampshire, California, New York, Massachusetts, Maryland and Virginia, as well as U.S. District Courts throughout the country and in Puerto Rico and the Virgin Islands. These court cases encompassed environmental, toxic tort, employment discrimination and contract disputes.For more than 20 years, Mr. Stack has focused primarily on litigating environmental, product liability and toxic tort cases, including complex mass tort claims. His responsibilities have included MTBE litigation nationwide, including consolidated multi-district litigation involving MTBE products liability. His experience includes class certification hearings in numerous environmental and toxic tort cases. He and his staff at ExxonMobil also supervised a regional counsel network responsible for litigation matters across several states.Earlier in his tenure at ExxonMobil, Mr. Stack served as an adviser on environmental compliance issues related to exploration, production, shale mining and chemical manufacturing, and also advised on marketing operations. Prior to joining ExxonMobil in 1977, Mr. Stack began his career as a staff attorney in the Office of Counsel to the Governor of New Jersey, where he handled matters involving the Department of Labor and Industry, the Department of Environmental Protection and the Public Utilities Commission.