Antitrust/Competition Merger Review
We get deals cleared. Our deep understanding of competition authorities gives us the insight, experience, and credibility to secure cost-effective worldwide approval of complex transactions. We rely on frequent dealings with the regulatory agencies, and our team includes former senior government antitrust enforcers. Because of our track record, clients retain us to lead antitrust clearance, even when they use other firms as corporate counsel.
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Global Reach and Coordination: Our extensive bench of competition attorneys practice before the U.S., EU, and UK competition authorities. We also regularly act as global coordinator of merger and foreign direct investment (FDI) review. We draw on a network of leading independent antitrust and FDI specialists across over 45 jurisdictions, enabling us to provide a “one-stop shop” experience for our clients.
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Deep Understanding of Global Competition Authorities: Our antitrust attorneys have held significant senior leadership positions in the Federal Trade Commission, Department of Justice, and the European Commission.
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A Team Built to Handle the Toughest Transactions: Our team has been entrusted with our clients’ most challenging mergers — 24 transactions valued at more than US$1 billion and 21 in-depth merger investigations in the last three years alone.
Experience Highlights
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Pfizer in its US$43 billion acquisition of Seagen Inc., a world leader in antibody-drug conjugates (ADCs).
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Sony in its US$3.6 billion acquisition of game software developer Bungie.
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Thermo Fisher Scientific in its US$21 billion Acquisition of PPD, a global contract research organization.
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Fitbit in its US$2.1 billion sale to Google.
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BP in securing FTC clearance of its US$5.6 billion sale of BP's entire business in Alaska, including all of its upstream and midstream businesses in the state, to Hilcorp, the largest private operator in Alaska.
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AbbVie in its US$63 billion acquisition of Allergan, manufacturer of the well-known medication Botox.
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Bristol-Myers Squibb in numerous transactions, including its US$90 billion acquisition of Celgene.
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Boston Scientific in its US$4.2 billion acquisition of BTG plc and its related divestiture of microspheres business to Varian Medical Systems.
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Adobe in obtaining clearance regarding the company's US$4.75 billion acquisition of Marketo, the leading marketing cloud platform for business-to-business marketing engagement.
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AT&T Inc. in its successful US$85.4 billion stock-and-cash acquisition of Time Warner Inc., in which Arnold & Porter successfully defended the first vertical merger trial and appeal in decades.
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Monsanto Company in the company's US$66 billion acquisition by Bayer, as well as coordination of antitrust/competition approvals in almost 30 other jurisdictions worldwide.
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General Electric in the company's €12.35 billion acquisition of Alstom.
Key Contacts
Related Services
Recognition
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Chambers GlobalCompetition/Antitrust (Global-wide) (2024)
Competition/European Law (Belgium) (2024)
Competition/Antitrust (USA) (2024)
Competition/Antitrust (International & Cross-Border) (2024) -
Chambers EuropeCompetition/European Law (Belgium) (2011–2018, 2023)
Competition/Antitrust (Europe-wide) (2014–2015) -
LMG Life Sciences AwardsLife Cycle Firm of the Year - United States (2023)
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Chambers USAAntitrust (Nationwide, Washington, D.C., New York) (2024)
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Global Competition Review"GCR Global Elite"—World's top 15 firms for competition (2008–2025)
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The Legal 500 USAntitrust: Merger Control (2024)
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The Legal 500 UKCorporate & Commercial: EU & Competition (2023)
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International Financial Law Review (IFLR)"M&A Deal of the Year" (2015)
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U.S. News & World Report and Best Lawyers"Best Law Firms" for Antitrust – National, New York, Washington, D.C. (2025)
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The Vault Guide to the Top 100 Law FirmsAntitrust (2023)
