Kenneth S. Reinker’s practice focuses on all aspects of antitrust law, including litigation, government investigations, and merger review.

Ken’s practice spans all industries, including extensive experience in pharmaceuticals, medical devices, and health care; high-technology industries; media; and financial institutions.

Ken has particular experience in the application of economics to legal matters and in working with economic experts. After law school and prior to joining the firm, he worked as an antitrust economist consulting on monopolization litigation as executive director of Legal Economics LLC.

In addition to appearing before U.S. courts and regulators, he has had in-depth involvement with China’s Ministry of Commerce (MOFCOM) and other global regulators.

Ken joined the firm in 2010 and became a partner in 2017.

Notable Experience

Litigation and Investigation Highlights

  • Sabre in defending lawsuits by American Airlines and US Airways challenging non-discrimination provisions in their agreements to distribute flights and fares through Sabre’s computerized reservation systems.

  • A major financial institution in global investigations into FX trading.

  • ArcelorMittal in a class action alleging an industry-wide agreement to reduce steel output.

  • Mallinckrodt in connection with FTC monopolization investigation involving the acquisition of an alleged nascent competitor.

  • A major automotive parts company, as well as an individual and third-parties, in the U.S. Department of Justice’s investigations into industry-wide price fixing.

  • Harper Collins in connection with the consent decree in the DOJ’s e-books investigation.

  • A health care data services company in defense of a FTC investigation into the company’s business practices, including alleged exclusivity provisions and alleged most favored nations provisions.

  • Multiple pharmaceutical companies in connection with patent settlement issues.

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Merger Review Highlights

  • 21st Century Fox in U.S. antitrust aspects of its $52 billion sale of its film and television studios and certain cable networks to The Walt Disney Company.

  • Western Digital in its $17 billion acquisition of SanDisk and its prior $4.8 billion acquisition of Hitachi’s hard-drive business.

  • Family Dollar in its $9.3 billion acquisition by Dollar Tree and its rejection of Dollar General’s hostile tender offer on antitrust grounds.

  • IMS Health in its $17.6 billion merger with Quintiles and its prior acquisitions of Cegedim’s CRM and strategic data businesses and of SDI Health.

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

  • Haldex in an unsolicited takeover offer by Knorr-Bremse that involved two of the largest truck brake suppliers, as well as competing bids ZF Friedrichshafen and SAF-Holland.

  • Meda in its $9.9 billion acquisition by Mylan.

  • Vista Equity Partners in its acquisition of Cvent, an event software provider.

  • Thales in its €4.6 billion acquisition of Gemalto.

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Selected Activities

  • Articles Co-Chair, Harvard Law Review, Harvard Law School
  • Olin Fellow in Law, Economics and Business, Harvard Law School
  • Teaching Fellow, Antitrust Economics, Harvard University, 2005


The Dominance and Monopolies Review, chapter on United States (1st ed. 2013; 2nd ed. 2014; 3rd ed. 2015; 4th ed. 2016; 5th ed. 2017; 6th ed. 2018; 7th ed. 2019; 8th ed. 2020).

HiQ v. LinkedIn: Antitrust Issues with Barring Rivals from Web Scraping,” ABA’s Icarus newsletter, August 5, 2020

U.S. Agencies Publish Final Revised Vertical Merger Guidelines,” Cleary Gottlieb Alert Memorandum, July 2, 2020

Avoiding or Defeating Potential Antitrust and Other Civil Suits Relating to Anti-Price Gouging Laws,” Cleary Gottlieb Alert Memorandum, co-author, June 12, 2020

Market Definition and Competitive Effects in Merger Review: The Staples-Office Depot Example,” The Antitrust Counselor, 2016.