Antitrust

Michael is the rare antitrust lawyer who maintains both an active merger control practice and a bustling litigation practice. In 2025, for example, he shepherded over $65 billion of transactions through global merger control regimes, including a litigated merger challenge in the U.S., while also representing over a dozen clients in major antitrust litigation.  

Mergers & Acquisitions

• CWT US LLC, a global business travel and meetings solution provider, in its $540 million acquisition by Global Business Travel Group Inc., a B2B software and services company for travel and expense. The U.S. DOJ investigated this transaction and challenged it in litigation in the Southern District of New York. On the eve of trial, the DOJ dismissed the lawsuit without remedies — the first-ever dismissal of a litigated merger challenge without remedies. This result earned The American Lawyer’s Litigator of the Week Runner-Up. In the U.K., Michael shepherded the team that obtained the first-ever reversal of a preliminary decision to block the merger. This matter was short-listed for the prestigious GCR merger matter of the year awards for both Europe and the Americas.
• Pactiv Evergreen Inc., a leading manufacturer and distributor of resh foodservice and food merchandizing products, as well as fresh beverage cartons, in its $6.7 billion combination with Novolex, a manufacturer of diverse packaging products. This transaction was awarded Law360’s Legal Lion of the Week.
• Pennant Group Inc. as the divestiture buyer in UnitedHealth’s acquisition of Amedisys Inc. by UnitedHealth’s Optum unit. This transaction was short-listed for the prestigious GCR merger matter of the year award for the Americas.
• Groq, a global leader in AI inference, on its nonexclusive licensing agreement with Nvidia for Groq’s inference technology.
• Filtration Group, a Madison Industries Company and global market-leading provider of mission-critical filtration solutions, in its $9.25 billion acquisition by Parker-Hannifin, a global leader in motion and control technologies.
• GTCR in its $24.25 billion sale of Worldpay, a global leader in merchant acquiring and payments processing, to Global Payments.
• Caithness Energy, privately held independent power producer, in its sale of its Moxie Freedom Energy Center in Pennsylvania and Caithness Energy and BlackRock’s Guernsey Power Station in Ohio to Talen Energy Corporation, a leading independent power producer, for $3.8 billion.
• Manufacturer of industrial products in merger investigation.
• Software company in merger investigation.
• Initiated novel Section 2 merger challenge in the financial services industry involving one of largest companies in the United States and a nascent competitor.*
• Litigated Section 7 merger challenge in the transportation technology industry from investigation through appeal.*
• Supervised first-ever live-witness Tunney Act hearing regarding merger consent decree, involving large pharmacy and insurance companies in healthcare industry.*
• Argued appeal of most significant vertical merger in past several decades in D.C. Circuit.*

Litigation and Investigations

• Fox Corporation in antitrust litigation brought by Newsmax in the Southern District of Florida and the Western District of Wisconsin over alleged monopolization.
• SAP in antitrust litigation brought by Celonis in the Northern District of California over alleged monopolization.
• Sunbelt Rentals in multidistrict class-action litigation consolidated in the Northern District of Illinois over alleged agreements regarding the price of rental equipment.
• Guild Mortgage in antitrust litigation in the Middle District of Tennessee over the alleged use of Optimal Blue software.
• Secured summary judgment for Align Technology, the maker of Invisalign, in a series of class actions alleging monopolization of multiple product markets through the use of alleged refusals to deal, discount programs and bundling of goods and services. Following class certification in November 2023, the Paul Hastings team secured summary judgement in both cases, a complete win for our client. Paul Hastings was recognized as a “runner up” for The American Lawyer’s Litigator of the Week.
• Secured dismissal of CA Student Living, a real estate company, in the defense of multidistrict antirust class-action lawsuits alleging that CA Student Living conspired to fix prices through the use of algorithmic revenue optimization software.
• Realtek Semiconductor in litigation over alleged monopolization and attempted monopolization with respect to the use of intellectual property, including Federal Circuit appeal.
• CACI in antitrust litigation over alleged agreements regarding market allocation of naval engineers.
• Secured dismissal of Mustang Pipeline, a joint venture of Exxon and Enbridge, from antitrust litigation involving alleged monopolization.
• NHK in series of class actions involving alleged price-fixing, including Ninth Circuit appeal.
• Biotechnology company bluebird in defense of antitrust and RICO claims over development of FDA-approved drug.
• Green Plains in litigation at intersection of antitrust, employment and labor.
• Numerous leading technology, financial services and industrial companies in third-party merger litigation.
• Numerous software, financial services, fintech, medical device, life sciences and other companies in confidential conduct investigations before federal agencies.
• Multiple trade associations in variety of antitrust matters.
• Major medical device company in litigation at intersection of antitrust and intellectual property.
• Major pharmaceutical company in antitrust investigation.
• Major pharmaceutical company in global risk assessment of business structure.
• Financial services company before government agencies.
• Fintech company in antitrust investigation.
• Entertainment company in government investigation.
• Multiple entertainment and telecommunications companies in design and implementation of compliance systems and policies.
• Oversaw largest consent decree enforcement in the past twenty years, involving major players in media and entertainment industry.*
• Served as highest-ranking Antitrust Division official in technology investigations, which culminated in landmark Section 2 monopolization lawsuit.*
• Argued appeal of most significant monopolization case in past several decades in Ninth Circuit.*

Appellate and Complex Litigation

• Lead counsel for trade association Chamber of Commerce of the United States of America in challenge to Consumer Financial Protection Bureau’s amendments to Regulation Z regarding credit card late fees, resulting in preliminary injunction and novel appellate proceedings, including multiple successful mandamus petitions in the Fifth Circuit. This matter won The American Lawyer’s Litigator of the Week Runner-Up and Law360’s Legal Lion of the Week runner-up.
• Co-lead counsel for trade association CCST in successful challenge to multiple rulemakings by U.S. Department of Education, resulting in nationwide preliminary injunction and successful Fifth Circuit appeal.
• Lead counsel for healthcare trade association challenging Colorado regulatory regime on constitutional grounds, including Tenth Circuit appeal.
• Appellate counsel for NHK in antitrust appeal in class actions involving FTAIA.
• Appellate counsel for Realtek in Federal Circuit appeal.
• Argued appeal of most significant vertical merger in past several decades in D.C. Circuit.*
• Argued appeal of most significant monopolization case in past several decades in Ninth Circuit.*
• Argued appeal of largest healthcare fraud sentence in nation’s history.*
• Led Federal Circuit en banc briefing on Section 101 patent eligibility issues.*
• Led DOJ team successfully defending neutrality rules (Mozilla Corp. v. FCC, D.C. Circuit).*

Matters may have been completed before joining Paul Hastings.

Engagements

• ABA Spring Meeting Panel on Monopoly Broth, Moderator (Mar. 2025)
• "Antitrust in the Digital Economy", GCR Live, Speaker (Mar. 2025)
• "M&A and the Future", Columbia Law School, Speaker (Nov. 2024) 
• "Antitrust Merger Guidelines", Ad Item Corporate Counsel Network, Speaker (Feb. 2024) 
• Antitrust in Labor Markets, Speaker (Nov. 2024)
• "Antitrust Developments," Deerfield at Cure, Speaker (Nov. 2023)
• "Breaking News: FTC v. Amazon," ABA Panel, Speaker (Oct. 2023)
• "Biden at 2," ABA Trust and Trade Podcast, Speaker (Feb. 2023)
• "Beyond Spoofing: What’s Next for CFTC and DOJ Enforcement," Futures Industry Association, Speaker (2022)
• "Antitrust in the Financial Sector: Competition in Traditional Banking Services," Concurrences, Speaker (2022)
• "Regulatory Outlook," U.S. Chamber of Commerce, Speaker (2022)
• "Life Sciences and IP: Navigating the Current Antitrust Environment," Speaker (Dec. 1, 2021)
• "Vertically Challenged," ABA Panel, Speaker (2021)
• "Courthouse Steps Decision Webinar: NCAA v. Alston," Teleforum, Speaker (2021)
• "Implications of 1-800 Contacts v. FTC," ABA Panel, Speaker (2021)
• "The Muscular Role for Antitrust in Fintech, Financial Markets, and Banking," University of Michigan Law School, Speaker (2020)
• "Antitrust Federalism," George Mason University Law School, Speaker (2020)
• "Recent Developments and Emerging Trends in Litigation," N.Y. State Bar Association, Speaker (2020)
• "The Jurisprudence of Direct and Indirect Purchasers," International Business Competition Committee, Speaker (2019)
• "Meet the DAAGs," ABA Spring Meeting, Speaker (2019)
• "Innovation & Competition Policy," Mentor Group, Speaker (2019)
• "Antitrust Enforcement in Labor Markets," Santa Clara University, Speaker (2019)

Publications

• "'Shadow Settlements' and the Tunney Act," CPI Antitrust Chronicle, Author (Nov. 2023)
• "Mitigating Labor Antitrust Risks as Enforcement Ramps Up," Law360, Author (June 16, 2022)
• "How To Mitigate Antitrust Risk In ESG Efforts," Law360, Author (Oct. 19, 2021)
• "Private Management of Public Spaces," Harvard Environmental Law Review, Author (2010)
• "The Law of Describing Accidents," Yale Law Journal Author (2009)

• Vice-Chair – ABA Antitrust Section’s Unilateral Conduct Committee
• Former Vice-Chair – ABA Antitrust Section’s Federal Civil Enforcement Committee 
• Member – U.S. Chamber of Commerce Antitrust Council