Mr. Gidley served as the Acting Assistant Attorney General for the US Department of Justice (DOJ) Antitrust Division in 1992 – 1993 with responsibility for all civil, criminal and merger matters of the Division. Prior to that, he served as Deputy Assistant Attorney General for Regulated Industries in the Antitrust Division from 1991 – 1992, responsible for civil, criminal, and merger matters in the telecommunications, energy, computers, intellectual property, and banking and finance industries. From 1990 to 1991, Mr. Gidley served as Associate Deputy Attorney General under then Deputy Attorney William P. Barr, during the first Bush Administration. During his tenure at the Antitrust Division, he worked on a number of merger and acquisition investigations, including Bank of America's acquisition of Security Pacific National Bank and worked on the development of the seminal DOJ-FTC 1992 Horizontal Merger Guidelines. Mr. Gidley participated in CFIUS merger review deliberations, representing the Justice Department. He brought the successful and influential lawsuit under Section 1 of the Sherman Act against the major US domestic air carriers for alleged price fixing and cartel behavior (the Airline Tariff Publishing Co.). Mr. Gidley also supervised the Division's investigation of price fixing in the US Treasury bond auction market, which resulted in a $28 million asset forfeiture action against Salomon Brothers — at that time the largest antitrust penalty ever in the Division's history for cartel activity.
In December 2014, The National Law Journal named Mr. Gidley one of the inaugural Top 50 US Litigation Trailblazers. Law360 named Mr. Gidley one of a handful of MVPs in Competition Law in 2013. Legal 500 writes that "practice head Mark Gidley sets 'the gold standard' in terms of expertise, responsiveness and value. 'Alone or with a team, there is no finer strategist or counselor in Washington DC; he makes you feel like his only client.'" (Legal 500, 2013). "Mark Gidley . . . is renowned for his expertise in pharmaceuticals and his knowledge of cartel matters." (Chambers, 2014). "Mark Gidley has constructed a team that is both whip-smart and composed of born-and-bred contrarians who believe cases are worth fighting, especially if a prosecutor has chosen to stand on shaky legal ground." (Global Competition Review, 2015).
Mr. Gidley represents parties before the US competition agencies — the FTC and the Antitrust Division — as well as parties in criminal grand jury and civil investigations of pricing conduct, and other potential antitrust violations. His work often features investigations of transnational firms in grand jury investigations, parallel class action suits, and civil investigations of pricing and other competitive practices. Mr. Gidley represents antitrust defendants in multi-forum cases that involve parallel, simultaneous government investigations and multiple civil actions. His cases have often involved parallel investigations by competition agencies outside the United States such as the European Commission, national European authorities, and competition agencies in Canada, Mexico, Korea, Australia, New Zealand, Taiwan, Brazil and Japan. His cartel cases have established fundamental due process rights for companies and individuals. In criminal cartel investigations, Mr. Gidley has represented corporate clients and individuals in a variety of industries, including auto parts, oil and gas leasing, air cargo, defense contracting, ocean shipping, beverages, graphite electrodes, DRAM, and LCD.
Mr. Gidley is among the most experienced lawyers in the US in trying criminal and civil antitrust cases, whether involving claims of price-fixing, monopolization, or stemming from a merger. His cases have shaped modern antitrust law in mergers, cartels and pharma antitrust. Mr. Gidley’s trial experience informs his approach to evidence gathering, dispositive motions, and counseling clients.
Mr. Gidley has an active merger and joint venture practice, representing merging parties before the DOJ and the FTC, including numerous companies in connection with mergers, acquisitions and joint ventures in industries ranging from health-care, telecommunications, pharmaceuticals, computer software, defense, retailing and publishing to engineering, energy, chemicals, minerals and industrial and consumer goods.Mr. Gidley's experience in transnational transactions spanning multiple and often conflicting antitrust regimes includes being co-editor of the Worldwide Merger Notification Requirements, a comprehensive compendium of global merger filing regimes in more than 210 jurisdictions, based on the firm’s global merger clearance experience.
Mr. Gidley was selected and served on the ABA Antitrust Section’s Blue Ribbon Panel for Civil Jury Instructions in Antitrust Trials in 2014.
Mr. Gidley is a leading antitrust lawyer and has recently been featured in Legal 500 US, Chambers USA, Best Lawyers in America, Asialaw Leading Lawyers, Super Lawyers, Who's Who Legal and Euromoney. Mr. Gidley was also chosen in a survey of in-house counsel and antitrust practitioners as the leading US competition lawyer under 45, and one of the top ten in the world by Global Competition Review's "45 Under 45" survey of leading antitrust lawyers.