William J Brennan


  • Massachusetts
  • New York
  • US District Court, Massachusetts
  • US District Court, Eastern and Southern Districts of New York


  • University of Pennsylvania Law School, JD (cum laude), 2000
  • Haverford College, BA, 1991

Will is a Partner with the firm and is based in the New York office. He has handled a broad array of insurance coverage and commercial litigation matters for the firm’s insurance and corporate sector clients. He is regularly called upon to evaluate or litigate complex coverage disputes involving insurance for professional liability (including coverage for Architects & Engineers, Bankers, and Lawyers), product contamination/product recall, financial institutions, environmental liability, directors and officers, media, cyber, and general liability matters. Will has litigated coverage disputes on behalf of insurers in federal and/or state courts in New York, California, Texas, Wisconsin, Utah, California, Rhode Island, and Tennessee, as well as in Bermuda-form arbitrations.

In addition, Will’s commercial defense background includes cases involving construction defect, trademark infringement, product liability and employment-related issues.

Work highlights

  • Advised London Market insurers concerning E&O coverage for large construction dispute in Northern Australia
  • Won partial motion to dismiss in New York reinsurance dispute involving bankers professional liability coverage
  • Won summary judgment for excess insurer in Texas lawsuit over Directors & Officers coverage for Delaware appraisal action
  • Won motion for judgment on the pleadings in Wisconsin lawsuit over professional liability policy issued to property management company
  • Second chaired Bermuda-form arbitration to favorable decision finding no coverage under product recall/adverse publicity policy.
  • Represented insurer in successful defense in Bermuda-form arbitration of claim under railroad policy involving $500M+ in alleged losses.
  • Won dismissal of claims against a component manufacturer in product liability case in New York state court based on application of economic loss doctrine.

Presentations and publications

  • Co- Author, "Delaware Supreme Court expands the application of Delaware law in D&O coverage disputes," published for Kennedys (March 2021)
  • “A Problematic Ruling on Photographing Police in Public,” published in Law360 (March 25, 2016)
  • “Ventura v. Kyle: Media Cos. Fear Expansion of Defamation Risk,” published in Law360 (May 4, 2015)