John R. Dierking is a partner in Holland & Knight's Orlando office and is a member of the firm's Mergers and Acquisitions Team. He represents clients in a variety of antitrust, financing and general corporate matters. In his antitrust practice, Mr. Dierking regularly advises clients on the competition law issues with respect to mergers and acquisitions. He also represents clients in the review process with the U.S. Department of Justice (DOJ) and the Federal Trade Commission (FTC) pursuant to the Hart-Scott-Rodino Act. Mr. Dierking has filed hundreds of premerger notification forms on behalf of clients and has provided Hart-Scott-Rodino counseling on many additional matters. These transactions have included numerous substantive merger investigations and responses to "second requests" by both the FTC and DOJ. He has also managed multinational merger filings in many transactions.

Representing a broad array of industries throughout the world, including healthcare, rail, defense contractors, retail chains, grocery store chains, insurance, pharmaceuticals, shipping, electronics manufacturing and security, Mr. Dierking has obtained antitrust regulatory clearance for numerous clients, including Harris Corporation, PharMerica Corporation, Epiq Systems Inc., Formosa Plastics Corporation, CGI Group Inc., SRA International Inc., Kistefos AS, Jabil Inc. and Brown & Brown Inc.

In addition, Mr. Dierking recently represented a datacenter and internet exchange services provider before the DOJ in connection with an investigation of a proposed acquisition, as well as a medical equipment business in connection with the FTC's investigation of an acquisition. Both representations resulted in the closing of the investigations by the respective regulators.

Mr. Dierking authors the firm's client alerts regarding regulatory developments under the Hart-Scott-Rodino Act, and he recently assisted with updates to the American Bar Association Section of Antitrust Law Premerger Notification Practice Manual Fifth Edition. The publication is widely considered the most comprehensive collection and explanation of Hart-Scott-Rodino interpretations for use by both company counsel and antitrust practitioners.

In addition to his antitrust practice, Mr. Dierking regularly represents commercial banks and other lenders, as well as corporate and non-corporate borrowers in complex commercial lending transactions, including asset-based financing transactions over multiple industries. His extensive experience in all aspects of commercial finance transactions includes structuring and preparation of loan agreements, requisite security documentation and protection of security interests, intercreditor agreements and opinions of counsel. He also serves on the firm's Business Law Opinions Committee.

Representative Experience


  • University of Florida Levin College of Law, J.D., with honors
  • University of Central Florida, B.S.B.A., Finance
Bar Admissions/Licenses
  • Florida
  • Florida Board of Bar Examiners, Supreme Court of Florida, 2018-2023
  • Kiwanis Club of South Lake
  • Orange County Bar Association
  • American Bar Association, Antitrust Law Section
Honors & Awards
  • Holland & Knight Pro Bono All-Star, 2020
  • The Florida Bar President's Pro Bono Service Award, 9th Judicial Circuit, 2018
  • Judge J. C. "Jake" Stone Distinguished Service Award, Legal Aid Society of the Orange County Bar Association, 2017
  • Award of Excellence, Legal Aid Society of the Orange County Bar Association, 2007
  • Martindale-Hubbell AV Preeminent Peer Review Rated
  • Order of the Coif
  • Who's Who Among American Law Students


Speaking Engagements