Leo Caseria

Leo Caseria is Co-Chair of both the firm’s Antitrust and Competition Practice Group and Governmental Practice and a partner in the Washington, D.C. and Los Angeles offices.

Areas of Practice

Leo’s practice focuses on defending companies in complex antitrust litigation, and navigating clients through antitrust and HSR issues in M&A transactions. He has led and supervised the defense of antitrust litigation matters involving a wide variety of alleged conspiracies and monopolization, including through trial. He has also led and supervised everything from HSR filing through Second Request for merging parties.

Clients rely on Leo for practical, effective, and creative strategies, as well as his expertise with certain industries, including construction materials, multifamily, and healthcare. Clients have commented to Chambers that Leo is their preferred antitrust counsel because his knowledge/expertise is “strong” and “tremendous.”

Leo’s litigation strategies have helped clients in multiple matters. Leo argued for and obtained a favorable summary judgment ruling for a defendant in an antitrust conspiracy case, eliminating a significant amount of potential liability. The key evidence came from a FOIA request to a state agency, which showed that plaintiff’s alleged injury in a particular state was not caused by defendants’ conduct.

In another example, a state attorney general sought $375 million in civil penalties from a defendant, arguing that its participation in a 12-year antitrust conspiracy involved hundreds of violations subject to separate penalties. Leo argued for and obtained a ruling that the state’s position was “manifestly unfair.” The court capped potential civil penalties at no more than $2.5 million.

Leo is one of the leading attorneys in the nation on antitrust matters relating to construction materials (including cement, concrete, asphalt, and aggregates). Leo has helped clients close billions of dollars worth of construction materials M&A deals by guiding them through the antitrust issues, including CRH’s $2.1 billion acquisition of Eco Materials (2025), Knife River’s $454 million acquisition of Strata (2025), CalPortland’s $160 million acquisition of Grimes Rock (2025), Chaney Enterprises’ acquisition of Chandler Concrete (2024), CalPortland’s $250 million of a cement plant from Martin Marietta (2022), and many other transactions (represented the buyer on each transaction listed). Leo’s experience includes multiple meetings with and presentations to both FTC and DOJ (including to FTC commissioners and DOJ Section Chiefs) on behalf of construction materials clients. Leo’s work for construction materials clients also includes litigation and investigations. For example, Leo represented a cement producer in a price fixing case, and he represented a ready-mixed concrete producer in a government price fixing and market allocation investigation.

Experience

Representative Engagements:

Litigation

• Defending Realty One Group, Inc. against antitrust claims relating to alleged conspiracy to fix buyer broker commissions on residential real estate transactions. 
• Defending Essex Property Trust (NYSE: ESS) against antitrust claims relating to alleged conspiracy to fix rental rates for multifamily apartment units. Competitors allegedly carried out the conspiracy using industry software and algorithm provided by RealPage. In re RealPage, Inc. Rental Software Antitrust Litigation (No. II), Case No. 23-3071 (M.D. Tenn.)
• Defending Veris Residential (NYSE: VRE) against antitrust claims brought by New Jersey attorney general relating to alleged conspiracy to fix rental rates for multifamily apartment units. Competitors allegedly carried out the conspiracy using industry software and algorithm provided by RealPage. Platkin v. Realpage, Inc., Case No. 2:25-cv-03057 (D.N.J.)
• Defending Hartford HealthCare Corporation against monopolization claims brought by competitor Saint Francis Hospital and Medical Center in federal court, and also against antitrust class actions in both state and federal court. Saint Francis Hospital and Medical Center, Inc. v. Hartford HealthCare Corporation, Case No. 3:22-cv-00050-AVC (D. Conn.); John Brown et al. v. Hartford HealthCare Corp., Case No. HHD-CV22-6152239-S (Superior Court of the Judicial District of Hartford); Estuary Transit District and Teamsters 671 Health Service & Insurance Plan v. Hartford HealthCare Corporation, Case No. 3:24-cv-01051 (D. Conn.)
• Defending honey importer Export Packers Company Limited dba Odem International against an antitrust and RICO class action brought by a putative class of U.S. domestic beekeepers, relating to a purported conspiracy to sell foreign fake honey. All claims dismissed. Henry’s Bullfrog Bees v. Sunland Trading, Inc., Case No. 2:21-CV-00582-TLN-CKD (E.D. Cal. Order dated Feb. 23, 2022).
• Defended Cyient, Inc. against antitrust claims brought by a putative class of aerospace engineers alleging a “no-poach” conspiracy between employers not to hire from each other from 2011 to the present. Borozny et al. v. Raytheon Technologies Corporation, Pratt & Whitney Division, et al., Case No 3:21-cv-01657 (D. Conn.).
• Defended The Reynolds and Reynolds Company against state and federal antitrust claims relating to data management system access. Monopolization and attempted monopolization claims dismissed at pleading stage. Motor Vehicle Software Corporation v. CDK Global, Inc., Case No. 17-896 (C.D. Cal. Order dated Oct. 2, 2017). Motion for summary judgment on conspiracy claims partially granted, eliminating majority of remaining potential liability. In re Dealer Management Systems Antitrust Litigation, Case No. 18-864 (N.D. Ill. Order dated Jun. 29, 2023).
• Defending JRK Residential Group, Inc. against putative class action alleging price gouging of apartment rental rates in California following wildfire emergencies. Felker v. JRK Residential Group, Inc., Case No. SCV-267587 (Sonoma County Superior Court).
• Co-lead trial counsel for defendants in two-month antitrust trial in 2019 before Judge Edward Davila in case involving alleged price-fixing and market allocation claims relating to telescopes. Successfully obtained summary judgment on below-cost pricing and refusal to deal issues prior to trial. Optronic Technologies Inc. v. Ningbo Sunny Electronic Co. Ltd. et al., Case No. 5:16-cv-06370 (N.D. Cal. Order dated Sept. 20, 2019).

Merger Review

• 2025: Represented CRH (NYSE: CRH) in connection with its $2.1 billion acquisition of Eco Materials, a provider of supplementary cementitious materials.
• 2025: Represented Knife River (NYSE: KNF) in connection with its $454 million acquisition of Strata Corp, a producer of ready-mixed concrete and aggregates.
• 2025: Represented CalPortland Company in connection its $160 million acquisition of Grimes Rock, a producer of ready-mixed concrete and aggregates.
• 2024: Represented Chaney Enterprises, Inc. in connection with its acquisition of Chandler Concrete, a producer of ready-mixed concrete and aggregates.
• 2015-2023: Represented CalPortland Company in connection with multiple acquisitions involving cement plants, cement terminals, and ready-mix concrete plants, including Second Request response. 

Conduct Investigations

• 2025: Represented third party multifamily property owner in connection with FTC antitrust investigation
• 2022: Represented ready-mix concrete producer in connection with confidential investigation relating to alleged antitrust conspiracy.
• 2022: Represented Smart & Final Stores, LLC and favorably resolved California attorney general investigation relating to alleged price gouging of eggs. People v. Smart & Final Stores, LLC, Case No. 22CIV01378 (Superior Court of the State of California, County of San Mateo). https://www.law360.com/articles/1481365/grocery-chain-pays-175k-in-calif-s-covid-price-gouge-suit
• 2020-2021: Represented several grocery store chains and favorably resolved confidential investigations by CA, NV, OR, and WA attorneys general, as well as local district attorneys, relating to alleged price gouging of food and grocery items.

Honors

• Competition Future Leader, GCR Who’s Who Legal, 2021-2023
• Next Generation Partner, Legal 500, 2019-2025
• Antitrust, Legal 500, 2015, 2017, 2019-2024
• Southern California Super Lawyer, Super Lawyers, 2021-2023
• Southern California Rising Star, Super Lawyers, 2018-2020

Articles

Antitrust Law Blog Posts

• "California Passes Broad Limits on 'Common Pricing Algorithms'," October 14, 2025

• "FTC Recommends Rollback of Anticompetitive Regulations," September 18, 2025

• "Cement and Concrete Admixture Price Fixing Conspiracy Allegations Not Strong Enough to Survive Motion to Dismiss," July 9, 2025
• "Thresholds for HSR Act Premerger Notifications and Interlocking Directorates Announced," January 13, 2025

• "Campaign Promises to Address Rising Prices at the Grocery Store Signal Stronger Price Gouging Investigations, Enforcement Actions, and Prohibitions to Come," November 1, 2024
• "The FTC Adopts New Premerger Notification Rules Implementing the Hart-Scott-Rodino (HSR) Act," October 14, 2024
• "FTC Votes to Ban Noncompete Agreements," April 24, 2024

• "Higher Jurisdictional and Filing Fees Thresholds for HSR Act Premerger Notifications and Interlocking Directorates Announced," January 23, 2024

• "The Wait is Over: DOJ and FTC Issue Final Merger Guidelines," December 20, 2023

• "DOJ Announces Mergers & Acquisitions Safe Harbor Policy," October 11, 2023

• "Mergers & Acquisitions Update: A Closer Look at the Impact of the FTC and DOJ’s Proposed HSR Act Filing Reform on Private Equity Firms," October 5, 2023

• "FTC Sues Private Equity Firm and Anesthesiology Practice for Antitrust Violations," September 26, 2023

• "A Big Deal: FTC and DOJ Issue Long-Awaited New Draft Merger Guidelines," July 20, 2023

• "Notice of Proposed Rulemaking: FTC Proposes to Redesign and Dramatically Expand the Scope of the HSR Act Filing Process," June 28, 2023

• "Supreme Court Holds That Respondents in Agency Enforcement Actions May Raise Constitutional Challenges Outside of Administrative Proceedings," April 19, 2023

• "No More Games: Activision Settles with DOJ Over Esports Compensation," April 5, 2023

• "DOJ Loses Third Consecutive Antitrust Labor Trial," March 24, 2023

• "Higher Jurisdictional and Filing Fees Thresholds for HSR Act Premerger Notifications and Interlocking Directorates Announced," January 24, 2023

• "A Blast from the Past: FTC Bringing Back Enforcement of Robinson-Patman Act," January 13, 2023

Books

Media Mentions

Speaking Engagements

• “Antitrust…Opening the Gates,” National Ready-Mixed Concrete Association’s ConcreteWorks conference, Denver, Colorado, October 1, 2022
• “Non-Competes and Non-Solicitation Clauses: What You Need to Know,” Association of Corporate Counsel New York chapter Annual Meeting, New York City, New York, September 21, 2022
• “The Price is Right: Examining Antitrust and Pricing Issues in the Hospitality Industry,” Sheppard Mullin Webinar, May 25, 2021
• "B2B Noncompetes and the Rule of Reason," Los Angeles County Bar Association Webinar, October 8, 2020
• “Trending Legal Issues in the Retail Industry,” Sheppard Mullin Webinar, June 16, 2020

Events

Memberships

• Co-Chair, Books and Treatises Committee, ABA Section of Antitrust Law, 2016-2024

Digital Media