Freshfields Bruckhaus Deringer has strengthened its Washington DC antitrust practice with the hire of a former senior lawyer from the US Department of Justice.

Eric Mahr left the US Department of Justice (DOJ) in November after just over two years serving as director of litigation of the antitrust division.

He joined the DOJ in 2015, following 20 years as a partner at Wilmer Cutler Pickering Hale & Dorr and its legacy firms in Washington DC and Brussels. He had a previous five-year stint as a trial lawyer at the DOJ, prior to going into private practice.

Speaking to Legal Week sister title The National Law Journal, Mahr said it had always been his intention to exit the Justice Department after a couple of years, but he decided to stay on a bit longer than anticipated to help smooth last year's transition between administrations.

Commenting on his move to Freshfields, he said: "What really stood out for me was the firm's energy and focus. They have a clear commitment and that's something that's very invigorating."

Mahr added: "Throughout my career, my two greatest interests – international antitrust and US litigation – have always been in some tension with one another; Freshfields provides the unique opportunity finally to bring them together."

Freshfields' US managing partner Peter Lyons said: "When it comes to US antitrust litigators, there's quite simply nobody else who offers the track record that Eric has, and nobody else who can offer our clients in the US and around the world as deep a level of hands-on knowledge."

Last year, the firm hired Shawn Cooley as special counsel in its Washington DC office, from the US Department of Homeland Security.

He was brought on board for his experience dealing with the Committee on Foreign Investment in the United States, the body that reviews foreign acquisitions of US businesses for possible national security implications.

Other key hires for Freshfields in the US include a trio of restructuring partners from Arnold & Porter Kaye Scholer who joined the firm in New York last year.

The firm made a serious push into the US in 2013-14 with a series of eye-catching hires, including former Wachtell Lipton Rosen & Katz partner Mitchell Presser and former Skadden Arps Slate Meagher & Flom banking partner James Douglas.

Last year the partnership voted to scrap its lockstep system, replacing it with a single ladder that will enable top performers to make six times more than those at the bottom.

The move aimed to give the firm greater ability to reward high-performing partners in key markets such as London and New York.