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

His U.S. practice background 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 European practice involves merger cases at both the EU and member state levels, and defending actions involving alleged restraints of trade and abuses of dominant position. 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

  • 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.

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

  • 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.

  • 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.

  • Deutsche Telekom in T-Mobile USA’s acquisition of MetroPCS, and in its proposed $39 billion sale of T-Mobile USA to AT&T.

  • 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

  • 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.

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

  • Citigroup in the DOJ investigation concerning potential anticompetitive conduct in the CDS industry.

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

  • UTAC in defending a patent litigation suit filed by Tessera.

  • A major financial institution in investigations in the U.S., Europe, and Asia concerning global FX trading.

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Selected Activities

  • Vice Chair, Books & Treatises, American Bar Association’s Antitrust Section
  • 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
  • Law Clerk, the Honorable Andrew J. Kleinfeld of the U.S. Court of Appeals for the Ninth Circuit, 1992-1993


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.

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