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William B. Monahan


William B. Monahan

New York +1-212-558-7375+1-212-558-7375 +1-212-558-3588+1-212-558-3588
[email protected]

Bill Monahan is head of the Firm’s Products Liability & Mass Torts Group and a partner in the Firm’s Litigation Group. He focuses on “bet-the-company,” products liability/mass tort, securities, shareholder/corporate governance, complex commercial, employment, ESG, and M&A litigation, as well as related governmental and internal investigations. For almost 20 years, Bill has represented prominent corporations and individuals in their most challenging cases, including at jury and bench trials, before arbitration panels, and on appeal in federal and state courts across the United States.  His corporate clients have included prominent automotive, pharmaceutical, healthcare, telecom, financial services, and computer companies.

Bill is currently spearheading the defense of Koninklijke Philips N.V. and its affiliates in its litigation across the globe relating to the June 2021 recall of certain CPAP, Bi-Level PAP, and mechanical ventilator devices, including consumer class actions, personal injury lawsuits, and shareholder litigation, as well as related regulatory inquiries. 


Products Liability & Mass Torts
  • ​Representing in the United States, and managing the defense on a global scale of, Koninklijke Philips N.V. and affiliates in hundreds of consumer class actions and personal injury lawsuits, as well as shareholder litigation and regulatory inquiries, related to the June 2021 recall of certain CPAP, Bi-Level PAP, and mechanical ventilator devices. Two MDLs have been established in the Western District of Pennsylvania.
  • Representing Volkswagen and Stellantis/FCA US LLC in numerous federal and state actions, including MDLs in San Francisco, as well as regulatory investigations, regarding allegations that certain of their diesel vehicles emitted nitrogen oxides in excess of the limits imposed by U.S. law. Litigation has included consumer class action litigation, opt-out litigation, securities litigation, dealer litigation, and litigation with the Department of Justice, the Securities and Exchange Commission, the Federal Trade Commission, and various State Attorneys General.
  • Represented Volkswagen in a three-week jury and bench trial in federal court in San Francisco. Following 11 days of trial, the jury rejected bellwether consumers’ claims seeking millions of dollars in damages after opting out of the related consumer class action settlements.
  • Represented Volkswagen and Audi in securing the dismissal on standing grounds—upheld on appeal—of a putative class action in the Northern District of California brought by individuals who both purchased and sold their diesel vehicles before news of the diesel emissions issues became public. Named The Am Law Litigation Daily’s “Litigator of the Week.”
  • Represented Volkswagen in successfully opposing class certification, and then obtaining summary judgment, in a putative nationwide consumer class action alleging fraud in connection with Volkswagen’s certified pre-owned vehicle program.
  • Secured the dismissal of most claims against FCA US LLC at the pleading stage in two putative nationwide consumer class actions in the Eastern District of Michigan concerning (i) two alleged defects in model year 2013-2017 Ram 2500 and 3500 diesel trucks, and (ii) an alleged defect in the Exhaust Gas Recirculation coolers in model year 2014–2019 Ram 1500 diesel trucks.

Securities Litigation, Corporate Governance Litigation and Complex Commercial Disputes

  • Representing AT&T in securing, at the pleading stage, the dismissal of two securities class actions in New York alleging violations of Section 10(b) of the Exchange Act and Sections 11 and 12 of the Securities Act of 1933 in connection with alleged misrepresentations regarding DIRECTV NOW, a video streaming product.
  • ​Represented various M&A contracting parties in various post-closing disputes before independent accountants and arbitration panels, including purchase price adjustments.
  • Represented Philips Healthcare in a contract action in California federal court alleging that Philips failed to adequately market a product pursuant to a license agreement.
  • Represented Fiat Chrysler Automobiles and Ferrari in obtaining the voluntary dismissal—following an oral argument at which the court issued a tentative ruling dismissing all claims—of a securities action in the Northern District of California alleging misstatements in connection with Fiat Chrysler’s 2016 spinoff of its remaining equity stake in Ferrari.
  • Representing Illinois Tool Works as plaintiff in litigation in Delaware Superior Court alleging that the defendant private equity firm fraudulently induced plaintiff into buying one of defendant’s portfolio companies.
  • Representing various companies in “Delaware-style” litigation, including shareholder derivative actions, M&A litigation, appraisal actions, and Section 220 “books and records” proceedings.
  • Represented Goldman Sachs in FINRA arbitration and related state court action concerning alleged investor losses arising from an investment in a mortgage-related product, culminating in a favorable decision from a panel of three arbitrators.
  • Represented Fiat Chrysler Automobiles in Delaware Chancery Court in a pricing dispute concerning the terms of a call option to purchase certain company membership units.
  • Represented CA Technologies in connection with its defense of claims brought in the New York federal courts concerning a shareholder proxy contest and, separately, a motion to overturn a settlement of class action and derivative litigation on the grounds of fraud.
  • Represented Microsoft in appeal in the Second Circuit Court of Appeals on plaintiffs’ theory that defendants fraudulently induced plaintiffs to enter into an agreement assigning certain patent applications to Microsoft.
  • Represented a pharmaceutical company in the District of Minnesota in litigation concerning the proper interpretation of a bond indenture.
  • Represented prominent former director of a Texas state savings bank that failed during the 2008 financial crisis in class action litigation in the Texas federal courts.
  • Represented a computer software company in the Delaware Supreme Court – in the first case ever certified by the SEC to the Delaware Supreme Court – concerning a proposed shareholder bylaw requiring the mandatory reimbursement of proxy solicitation expenses.


  • Advisory Board of the Perry Weitz Mass Tort Institute at Hofstra Law (2023)
  • Lawdragon – recognized as one of the “500 Leading Litigators in America” (2023)
  • AmLaw Litigation Daily – Shout out, “Litigator of the Week” (October 2021, January 21, 2022; January 28, 2022; December 2022)
  • AmLaw Litigation Daily – Runner up, “Litigator of the Week” (March 2020, May 2020, July 2022)
  • AmLaw Litigation Daily – “Litigator of the Week” (November 2020)
  • Law360 – Product Liability Editorial Advisory Board (2018, 2019)
  • Law360 – recognized as a “Rising Star” in Transportation (2017)
  • Benchmark Litigation – named a Top Litigator Under 40 (2017, 2018) and to the 40 & Under Hot List (2016, 2017, 2018)
  • New York Super Lawyers – recognized as a “Rising Star” in the areas of Securities, Business and Appellate Litigation (2013, 2014, 2015, 2016, 2017)
  • The Legal 500 United States (2014, 2015, 2016, 2017, 2018)
  • Sanctuary for Families – recipient of Above & Beyond Award for Excellence in Pro Bono Advocacy (2013)