Michael Moiseyev


Mike Moiseyev
Michael Moiseyev serves as co-head of Weil’s Antitrust practice in the U.S.

With a focus on transactions, Michael has a broad antitrust practice advising clients on both investigations and litigation. Drawing on his over 30 years of service at the Federal Trade Commission, including 16 years as Assistant Director leading the Mergers I Division in the Bureau of Competition, he provides clients with a unique, inside perspective on how the government investigates and litigates merger cases.

Utilizing his significant experience engaging with foreign competition authorities, including the European Commission, the UK Competition Markets Authority, and the Canada Competition Bureau, Michael represents companies worldwide in their most high-stakes litigations and complex transactions, securing approval from regulatory agencies across the globe. He has significant experience advising companies across industries and develops tailored approaches to navigate their most complex antitrust issues.

While in government service, Michael was one of the most well-known, respected, and successful antitrust officials in the country. As Assistant Director, he managed all aspects of the Mergers I division’s enforcement work, including oversight of investigations, formulation of legal theories, and preparing and presenting enforcement recommendations. During his tenure, he oversaw more than 100 significant merger reviews in a broad range of industries, from healthcare products and services, to technology products, to defense, scientific, and industrial products. Michael was responsible for the antitrust review of many of the largest mergers of the last decade: the BMS/Celgene, Pfizer/Wyeth, Teva/Allergan, GSK/Novartis, and Takeda/Shire pharmaceutical mergers, the Medtronic/Covidien and Abbott/St. Jude medical device transactions, Microsoft/LinkedIn, the Essilor/Luxottica optical merger, and in industrial products the Holcim/Lafarge cement and Praxair/Linde industrial gases mergers. Other significant investigations conducted under his leadership include Mallinckrodt(Questcor)/Novartis, which produced the largest equitable monetary relief ever by the government in a merger case, Hertz/DollarThrifty, Walgreens/Rite Aid, ESI/Medco, Google/DoubleClick and OrbitalATK/Northrop Grumman. Additionally, he oversaw and participated in litigation conducted by his division, including FTC v. Steris, the first potential competition case brought by the government in over twenty years, and the administrative challenge of the consummated Otto Bock/Freedom Innovations acquisition.

At the FTC, Michael was regularly called on to participate in many of the agency's most significant merger policy initiatives. Most recently, that work has included: the Vertical Merger Guidance Task Force whose work culminated in the recently issued Vertical Merger Guidelines; the portion of the “Hearings on Competition and Consumer Protection in the 21st Century” relating to Acquisitions of Nascent and Potential Competitors in Digital Technology Markets; and the “FTC's Merger Remedies 2006-2012” report. His work has been recognized by the FTC through numerous awards and he is a five-time recipient of the agency's Janet Steiger Team award.

His international antitrust work has included representing the FTC at the 2020 meeting of the International Competition Network Merger Working Group in Australia, which brings together 140 competition agencies, from 130 jurisdictions, providing a forum for sharing experience and addressing practical competition policy and enforcement issues, frequent participation in the FTC's international technical assistance program, and a secondment to the OECD's Competition Law and Policy Section. He is frequently invited to present on antitrust topics before government, industry and legal audiences.

Key Representations:

  • Microsoft in its $68.7 billion acquisition of Activision Blizzard, Inc., a leading publisher of popular PC, console and mobile games. This is a cross-border matter in which Weil serves as lead global antitrust counsel coordinating the regulatory process across several jurisdictions worldwide.
  • Microsoft in its $7.5 billion acquisition of ZeniMax Media, parent company of Bethesda Softworks, and other game studios
  • Meta Platforms (f/k/a Facebook) in its $1 billion acquisition of Kustomer, a customer relationship management (CRM) company.
  • Meta Platforms (f/k/a Facebook) in its acquisition of Within, the immersive media startup behind the VR fitness service Supernatural.
  • IQVIA in its effort to defend its proposed acquisition of Propel Media Inc., which owns DeepIntent, a healthcare advertising platform, in litigation with the FTC.
  • Represented Abbott Laboratories in its $850 million acquisition of Cardiovascular Systems, Inc. (CSI), a medical device company with an innovative atherectomy system used in treating peripheral and coronary artery disease.
  • Kantar Group (a portfolio company of Bain Capital Private Equity) in its acquisition of Numerator.
  • Regeneron in connection with a monopolization claim against Amgen for leveraging sales of Otezla and Embrel to boost sales of Amgen’s drug, Repatha.
  • Regeneron in connection with monopolization and other claims against Novartis relating to actions taken to prevent competition from Regeneron’s PFS version of Eylea.
  • RentPath, a leading digital media company in the real estate industry, in securing a favorable settlement related to a terminated purchase agreement by CoStar, and its subsequent $608 million sale to Redfin.
  • Eli Lilly in multiple transactions.

Firm News & Announcements, Awards and Recognition, Latest Thinking

Firm News & Announcements

View all

Awards and Recognition

Latest Thinking

View all