Global law firm Baker McKenzie is pleased to announce that former partner Mark Hamer will rejoin the Firm after completing his service as Deputy Assistant Attorney General of the Antitrust Division at the US Department of Justice (DOJ). Before his government service, Mark served as Global Chair of Baker McKenzie’s Antitrust & Competition Practice.
“We are thrilled to welcome Mark back to Baker McKenzie,” said Colin Murray, Baker McKenzie’s Americas Chief Executive Officer. “Mark was a valued colleague and leader at our Firm who helped lead the extraordinary growth and success of our antitrust practice. His recent DOJ leadership experience will provide unparalleled insight and value to clients who are facing real and potential antitrust enforcement.”
Mark joined DOJ in early 2025 as Deputy Assistant Attorney General, leading the DOJ’s civil antitrust enforcement program. He supervised the largest civil antitrust litigation portfolio in DOJ’s history, managing several high-profile antitrust enforcement actions in the technology, healthcare, entertainment, agriculture, real estate and financial services industries.
“Few antitrust lawyers can match the depth of Mark’s experience in senior levels of government and private practice,” said Creighton Macy, Global Chair of Baker McKenzie’s Antitrust & Competition Practice. "He will fit seamlessly back into our leading team, which he helped to build, and we look forward to working with him to help our clients manage increasingly complex litigation and regulatory risks. Our US team has grown fivefold in the last several years and we are confident that our tremendous momentum will only be amplified further as our longtime friend and colleague Mark rejoins us.”
Mark served as Global Chair of the Firm’s Antitrust & Competition Practice from 2020 to 2025, and previously served as its North America chair. Earlier in his career, Mark served as a senior Trial Attorney at DOJ’s Antitrust Division.
“When Assistant Attorney General Gail Slater asked me to join her as Deputy Assistant Attorney General at DOJ’s Antitrust Division, I committed to return to public service for a year. The year 2025 was the high-water mark for civil antitrust enforcement, with the largest docket of civil antitrust litigation matters in DOJ’s history. I am grateful to have had the opportunity to work alongside the exceptional individuals in DOJ’s Antitrust Division, and I am proud of the work we accomplished together,” said Mark. “I am excited to return home to my friends and colleagues at Baker McKenzie, and I am privileged to rejoin its world-class antitrust team.”
Baker McKenzie’s Antitrust & Competition Practice is one of the world’s largest and most geographically diverse with approximately 340 practitioners across 60 offices in more than 40 countries worldwide. Consistently recognized as a global leader, the group provides seamless, integrated counsel on a broad spectrum of complex competition law matters, including antitrust litigation, antitrust agency investigations, criminal and civil enforcement cases, and merger clearance matters. The team also regularly provides antitrust compliance guidance and training for clients.