Mark W. Nelson’s practice focuses on global antitrust matters, with an emphasis on merger cases and U.S. civil litigation.

His U.S. practice includes extensive merger work and antitrust counseling, and litigation experience in both civil and criminal matters, as well as in FTC administrative proceedings. Mark’s global practice involves merger cases before the European Commission and national authorities throughout Europe, Asia, and South America, as well as defending actions involving alleged restraints of trade and abuses of dominant position in EU proceedings. He has also been actively involved in litigation, investigations, and counseling in matters involving the intersection of antitrust and intellectual property law, in particular in the context of patent pools and standards-setting.

Mark joined the firm in 1993 and became a partner in 2002. He was resident in the Brussels office for three years.

Notable Experience

Merger Control

  • Deutsche Telekom and T-Mobile US in various antitrust matters including T-Mobile US’s merger with Sprint Corporation for a total combined enterprise value of $146 billion and obtaining DOJ and FCC clearance; previously, T-Mobile USA’s acquisition of MetroPCS, and its proposed $39 billion sale of T-Mobile USA to AT&T.

  • Thales in its €4.8 billion acquisition of Gemalto.

  • Lafarge in its €40 billion merger of equals with Holcim to create the world’s largest construction materials company. Named “Merger Control Matter of the Year – Europe” by Global Competition Review in 2015; previously its acquisition of Blue Circle Cement.

  • Google in the $2.91 billion sale of Motorola Mobility’s mobile devices business to Lenovo Group.

  • Tech Data Corporation in its $2.6 billion acquisition of the technology solutions business of Avnet, Inc.

  • IMS Health Holdings in its $17.6 billion merger of equals with Quintiles.

  • Samsung Electronics in the sale of its printer business to HP Inc. for $1.05 billion in cash.

  • EMC in the DOJ and FCO investigation of participation in the consortium (including Apple, Microsoft and Oracle) acquiring a portfolio of patents from Novell, as well as in previous acquisitions and its strategic worldwide partnership with Lenovo.

  • Kindred Healthcare in numerous transactions, including its $1.8 billion acquisition of Gentiva Health Services and in the acquisition of the company by a consortium consisting of TPG, Welsh Carson, and Humana.

  • Italmobiliare SpA in the announced $4.1 billion sale of its Italcementi SpA business to HeidelbergCement, including the combination of the parties’ U.S. building products subsidiaries.

  • BHP Billiton in several transactions including the demerger of its non-core assets to  South32, its sale of Pinto Valley copper mining operations and the associated San Manuel Arizona Railroad Company to Capstone Mining Corp., and its previous proposed $40 billion all-cash tender offer to acquire Potash Corporation of Saskatchewan.

  • OCI in the announced $8 billion sale of its North American, European and Global Distribution businesses to CF Industries.

  • OpenText in its $1.165 billion acquisition of GXS Group.

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Litigation and Investigations

  • T-Mobile and Deutsche Telekom in the federal court trial brought by a coalition of state attorneys general challenging the merger of T-Mobile and Sprint, which resulted in a combined company with an enterprise value of $146 billion.

  • Kawasaki Kisen Kaisha and its subsidiary “K” Line America in winning complete dismissal of class actions brought by direct and indirect purchasers of ocean vehicle carrier services. Previously advised “K” Line in antitrust investigations into price fixing in the car shipping industry, including advising in its plea agreement with the DOJ.

  • Citigroup in investigations in the U.S., Europe, and Asia concerning global FX trading, and in the DOJ investigation concerning potential anticompetitive conduct in the CDS industry.

  • ArcelorMittal in federal antitrust class action alleging an industry-wide agreement among steel producers to reduce output.

  • W.L. Gore & Associates in obtaining the closure (with no action taken) of its investigation into whether Gore’s business practices restricted competition in waterproof and breathable fabrics in violation of Section 5 of the FTC Act.

  • Lafarge in antitrust U.S. class action involving allegations of price fixing in the gypsum wallboard industry.

  • Broadcom in various matters, including its Third Circuit appellate victory against Qualcomm in a monopolization suit involving standard-setting issues.

  • UTAC in a patent licensing dispute and ultimate settlement agreement with Tessera relating to semiconductor technology.

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Selected Activities

  • Former vice chair, Books & Treatises, American Bar Association’s Antitrust Section
  • Former vice chair, Antitrust & Competition Law Committee, Intellectual Property Owners Association
  • Annual guest lecturer on EU competition law, George Mason University School of Law’s “European Union Law” course


Written articles and contributed to a variety of publications, including Global Competition Review, Competition Law of the European Community, Antitrust Law Developments, European Merger Control Law (chapter on U.S. merger control) and International Computer Law.

September 2020: T-Mobile Sprint: Winning The Case The Experts Said Couldn’t Be Won, Podcast, Episode 1The Deal

July 2020: U.S. Agencies Publish Final Revised Vertical Merger Guidelines

June 2020: Avoiding or Defeating Potential Antitrust and Other Civil Suits Relating to Anti-Price Gouging Laws

March 2012: Editor, Market Definition in Antitrust Theory and Case Studies (American Bar Association)

January 2012: The Case for Antitrust Law to Police the Patent Holdup Problem in the Standard Setting, Antitrust Law Journal