Leo Caseria is a partner in the Antitrust and Competition Practice Group in the Washington, D.C. and Los Angeles offices. 

Areas of Practice

Leo advises companies on antitrust issues in civil litigation, government investigations, mergers and acquisitions and proposed or contemplated business strategies. He has litigated numerous antitrust cases in federal and state courts, including cases based on alleged price-fixing, market allocation, boycott, monopolization and attempted monopolization.  He also has experience in consumer protection issues relating to price gouging.

Leo has obtained orders from several courts dismissing or significantly limiting antitrust claims against clients in industries such as automotive data management systems, consumer telescopes, consumer electronics and cement and concrete.  His antitrust litigation experience includes trial and appeal.

Leo is also knowledgeable regarding price gouging laws.  He has led the defense of several companies targeted in price gouging complaints or government investigations multiple states.  The products involved in the investigations Leo has handled include food, water, and consumer goods.

In addition, Leo regularly advises companies regarding the requirements under the Hart-Scott-Rodino (HSR) Act, prepares numerous HSR filings and works with economists to prepare submissions and presentations to government antitrust enforcers regarding proposed transactions. Leo represents clients before the U.S. Department of Justice and the Federal Trade Commission in connection with government antitrust investigations. 

Leo serves as Co-Chair of the Books and Treatises Committee of the American Bar Association's Section of Antitrust Law. He frequently edits or contributes to the Section’s antitrust handbooks, and also authored articles for SCOTUSblog and the New York Law Journal. He has been recognized as a "Rising Star" by Super Lawyers and in Legal 500.



Representative Engagements:

  • Defended Save Mart against putative class action alleging price gouging of eggs in California.  Plaintiff asserted a single claim under California’s Unfair Competition Law, Cal. Bus. & Prof. Code section 17200.  Claim against Save Mart was voluntarily dismissed after Save Mart filed a motion to dismiss.  Fraser v. Cal-Maine Foods, Inc., Case No. 20-2733 (N.D. Cal.).
  • Representing three different major retailers in connection with government price gouging investigations or complaints in California, Nevada, Oregon, and Washington, relating to products including eggs, bottled water, toilet paper, and disinfectant wipes.
  • Defended CalPortland against False Claims Act claims premised on alleged conspiracy to fix prices and allocate markets relating to cement, concrete and asphalt. All claims dismissed; affirmed by Ninth Circuit. U.S. ex rel. Rune Kraft v. CalPortland Construction, Case No. 16-4479 (C.D. Cal. order dated Mar. 9, 2018), aff’d, Case No. 18-55594 (9th Cir. opinion dated Apr. 7, 2020).
  • Defending telescope manufacturer against Sherman Act Section 1 and 2 claims and Clayton Act Section 7 claims. All claims in original complaint dismissed. Optronic Technologies, Inc. v. Ningbo Sunny Electronic Co., Ltd., Case No. 16-6370 (N.D. Cal. Order dated Sept. 28, 2017). Following amended complaint, claims based on below cost pricing, refusal to deal and conspiracy to prevent plaintiff from acquiring a telescope company defeated at summary judgment. Order dated Sept. 20, 2019.
  • Representing Samsung in global patent and standards related antitrust matters.
  • Defending The Reynolds and Reynolds Company against state and federal antitrust claims relating to data management system access. Monopolization and attempted monopolization claims dismissed. Motor Vehicle Software Corporation v. CDK Global, Inc., Case No. 17-896 (C.D. Cal. Order dated Oct. 2, 2017).
  • Defended The Reynolds and Reynolds Company against claims relating to data management system access. Plaintiff's request for temporary restraining order denied. Data Software Services, LLC v. The Reynolds and Reynolds Company, Case No. 17-1347 (C.D. Cal.).
  • Defended Samsung SDI against price-fixing actions brought by Oregon Attorney General. On a motion argued by Leo, Samsung SDI obtained an order capping the State of Oregon’s potential antitrust civil penalties to a maximum of $2.5 million, subject to possible additional reductions, as opposed to the $375 million sought by the State. State of Oregon v. LG Electronics, Inc., Case No. 1208-10246 (County of Multnomah, Order dated Nov. 23, 2016).
  • Defended Samsung SDI against price-fixing claims involving cathode ray tubes (CRT). In re Cathode Ray Tube (CRT) Antitrust Litig., MDL. No. 1917 (N.D. Cal.).
  • Defended Samsung SDI against multi-billion dollar price-fixing claim brought by Motorola. Claims dismissed just before trial. Motorola Mobility LLC v. AU Optronics Corporation, 09-cv-6610 (N.D. Ill.).
  • Defended Samsung SDI against price-fixing claims involving thin film transistor liquid crystal display products. In re TFT-LCD (FLAT PANEL) Antitrust Litigation, MDL. No 1827 (N.D. Cal.).
  • Represented Diamond Electric in international price-fixing investigation in the automotive sector.
  • Defended Samsung Electronics against multi-billion dollar group boycott claim brought by Rambus under California’s Cartwright Act concerning a certain type of DRAM. Rambus Inc. v. Micron Technology Inc., 04-0431105 (San Francisco Superior Court).
  • Defended Samsung against federal and state antitrust claims brought by direct and indirect purchasers of SRAM alleging horizontal conspiracy to exchange information for the purpose of fixing prices. In re SRAM Antitrust Litigation, MDL No. 1819 (N.D. Cal.).
  • Defended Live Nation and Clear Channel against Sherman Act § 2 monopolization claims brought by a purported class of purchasers of rock concert tickets. In re Live Concert Antitrust Litigation, MDL No. 1745 (C.D. Cal.).
  • Defended Philip Morris against Sherman Act § 1 challenge to the $246 billion dollar Master Settlement Agreement between leading tobacco companies and 46 states. Contributed to successful U.S. Supreme Court brief in opposition to petition for certiorari following favorable ruling by the Ninth Circuit Court of Appeals in Sanders v. Brown, 540 F.3d 903 (9th Cir. 2007).



  • Next Generation Lawyers, Legal 500, 2019-2020
  • Antitrust, Legal 500, 2015, 2017, 2019-2020
  • Southern California Rising Star, Super Lawyers, 2018-2020



Antitrust Law Blog Posts

Antitrust Books and Handbooks

  • Editor, Handbook on Antitrust in Technology Industries, ABA Section of Antitrust Law, 2017
  • Editor, State Action Practice Manual, ABA Section of Antitrust Law, Third Edition, 2017
  • Editor, Antitrust Evidence Handbook, ABA Section of Antitrust Law, Third Edition, 2016
  • Editor, Handbook on the Scope of Antitrust, ABA Section of Antitrust Law, 2015
  • Contributor, 2012 Annual Review of Antitrust Law Developments, ABA Section of Antitrust Law, 2013
  • Senior Editor, Handbook on Multijurisdictional Competition Law Investigations, ABA Section of Antitrust Law, 2010

Media Mentions

Speaking Engagements

  • "Joint Conduct 101: Information Exchange," ABA Section of Antitrust Law, Joint Conduct Committee, October 20, 2016



  • Co-Chair, Books and Treatises Committee, ABA Section of Antitrust Law, 2016-2023
  • Member, Antitrust and Unfair Competition Law Section, State Bar of California
  • Vice Chair, Books and Treatises Committee, ABA Section of Antitrust Law, 2014-2015

Digital Media


J.D., Columbia Law School, 2005, Harlan Fiske Stone Scholar

B.A., University of California, Los Angeles, 2002


  • California
  • District of Columbia
  • U.S. Court of Appeals for the Ninth Circuit
  • U.S. District Court for the Central District of California
  • U.S. District Court for the Eastern District of California
  • U.S. District Court for the Northern District of California
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