Eric is a litigation and antitrust partner in our Washington, DC office, and co-chair of the firm’s global antitrust litigation group.
Eric specializes in US antitrust litigation. For the past 20 years, he has represented clients in complex, high-stakes cases at trial and on appeal in federal district and appellate courts throughout the United States. He has defended clients in civil and criminal investigations, enforcement actions, and other regulatory proceedings both in the United States – before the US Department of Justice (DOJ) and the Federal Trade Commission – and in Europe, before the European Commission and numerous national competition authorities.
He has helped guide clients through second phase merger proceedings on both sides of the Atlantic, particularly where there was a significant potential for the relevant agency to challenge the transaction at issue.
From 2015 through 2017, Eric served as the Director of Litigation for the DOJ's Antitrust Division. In that role, he oversaw the Division's antitrust enforcement actions, with a focus on civil litigation and trials. The Division filed more than 10 contested cases during his tenure, and prepared for litigation in many more. Of the cases filed, the Division tried three to final judgment and won them all (US v. Aetna/Humana, US v. Anthem/Cigna and US v. EnergySolutions/WCS).
Eric was honored with the Attorney General’s Distinguished Service Award for the Aetna/Humana trial victory, and received the Assistant Attorney General’s Award of Distinction for serving as lead counsel in US v. United Continental/Delta (the Newark Slots matter).
Before his appointment as Director of Litigation, Eric spent 12 years as a partner in WilmerHale's Washington, DC office, and four years in that firm's Brussels office, where he practiced before the European Commission and various national competition authorities. He began his career as a trial attorney in the DOJ, Civil Division, Federal Programs Branch, after clerking for the Honorable Raymond J. Broderick of the US District Court for the Eastern District of Pennsylvania.
Making ACPERA Work Co-author with Sarah Licht, ANTITRUST Magazine (Summer 2015 at 31-36)
Competition Litigation Around the World, Chapter One: The United States Speaker, ABA Teleconference, ABA International Committee and the Civil Practice and Procedure Committee, Washington, D.C. (May 29, 2014)
Civil Litigation in the Aftermath of Criminal Litigation Speaker, ABA Section of Antitrust Law, 2014 Spring Meeting, Washington, D.C. (March 26, 2014)
ACPERA: Inscrutable or Just Forgettable? Co-author with Sarah Licht, ABA Section of Antitrust Law, 2014 Spring Meeting (February 19, 2014)
Civil Antitrust Risk in the United States Author, Acquisition International (January 2014)
Q&A with WilmerHale's Eric Mahr Law360's 2013 Q&A Series for Competition (April 1, 2013)