Jonathan S. Klarfeld is a veteran antitrust enforcer and practitioner who led many significant merger investigations and challenges during his 13 years at the Federal Trade Commission’s Bureau of Competition in Washington, D.C. Jonathan brings to Ropes & Gray clients a broad range of experience and knowledge about how antitrust reviews of transactions proceed, how consents are reached and how matters are litigated.  Since joining Ropes & Gray in the summer of 2014, he has represented and counseled clients across a broad range of antitrust issues and government investigations.

A staff attorney with the FTC from 2000 to 2008, Jonathan was named counsel to the director in 2008, where he oversaw several merger and non-merger divisions within the FTC. In 2009, Jonathan was appointed a Deputy Assistant Director in the Mergers I Division. In that role, he managed all aspects of the antitrust enforcement division in case selection, oversight and enforcement recommendation development. He also oversaw and participated in investigational hearings and depositions, negotiated consent agreements and litigated matters across a wide range of industries. Jonathan has supervised and led milestone antitrust cases, including toward the end of his agency tenure, the commission’s enforcement actions in Omnicare/PharMerica and Nielsen/Arbitron and its investigation of Express Scripts/Medco.

During his time at the FTC, Jonathan was detailed to the U.S. Attorney’s Office for the District of Columbia where he served as a Special Assistant U.S. Attorney, trying several cases and participating in all aspects of criminal prosecutions, including arraignments, plea negotiations, trials and oral arguments, witness preparations and sentencings.

Jonathan began his legal career in private practice as a litigation associate at Reboul, MacMurray, Hewitt, Maynard & Kristol.


  • Advised Bloomberg on antitrust aspects of its planned acquisition of Broadway Technology, a cutting-edge provider of high-performance front-office fintech solutions.
  • Represented Baring Private Equity Asia on the sale of the global surgical business of Lumenis LTD. to Boston Scientific. 
  • Represented Bain Capital before the FTC in its $18 billion acquisition of Toshiba Memory Corporation from Toshiba Corporation in a Bain Capital-led consortium including Apple, Seagate Technology, Kingston Technology, Hoya, Dell Technologies and SK Hynix.
  • Represented American Media, Inc. in its acquisition of Us Weekly from Wenner Media LLC before the Department of Justice.  The transaction closed without a Second Request.
  • Represented Emory Healthcare in its acquisition of Dekalb Medical before the FTC.  The transaction closed without a Second Request.
  • Represented Champion Enterprises Holdings, LLC in its acquisition of Skyline Corporation before the FTC.  The transaction closed without a Second Request.
  • Represented the proposed buyer of the assets to be divested from the Walgreens-Rite Aid transaction before the FTC.
  • Represented TPG Capital, L.P. in its $4.2 billion acquisition of McAfee from Intel Corp.
  • Represented the proposed buyer in the FTC investigation and subsequent litigation relating to the Staples-Office Depot transaction.
  • Represented Pfizer before the FTC in its $17 billion acquisition of Hospira.
  • Represented TPG Capital, L.P. before the FTC in its sale of Par Pharmaceuticals to Endo International plc.
  • Represented Berkshire Partners before the DOJ in connection with the acquisition of Fibertech Networks by Berkshire’s portfolio company Light Tower Fiber Networks. The acquisition closed without a Second Request.
  • Represented Key Food Stores Co-operative, Inc. before the FTC in its acquisition of 23 stores from The Great Atlantic & Pacific Tea Company (A&P), arising out of A&P’s bankruptcy proceeding.
  • Represented a third party in the FTC’s investigation and litigated challenge of Steris Corporation’s $1.9 billion acquisition of Synergy Health plc.
  • Represented Wright Medical Technology, Inc. before the FTC in connection with its $3.3 billion merger with Tornier N.V. The transaction closed with divestitures representing less than $15 million in revenue.
  • Represented Welsh Carson Anderson & Stowe and its portfolio company United Surgical Partners International (USPI) before the FTC relating to USPI’s combination with Tenet Healthcare. The transaction closed without a Second Request.
  • Represented Medtronic before the FTC in its acquisition of California startup Twelve Inc.
  • Represented HealthSouth Corp. in its acquisition of CareSouth Health System Inc., a private provider of home health services.

Areas of Practice