The Legal 500

Twitter Logo Youtube Circle Icon LinkedIn Icon

Sullivan & Cromwell LLP

Work +1 212 558 4000
Fax +1 212 558 3588

John Hardiman

Sullivan & Cromwell LLP

Work Department





Partner in Litigation Group and head of the Litigation Group’s Mergers and Acquisitions practice. Mr. Hardiman has worked on a wide range of high stakes contests for corporate control starting with British Petroleum’s purchase of Standard Oil in 1986. He also has considerable experience handling regulatory investigations for the Firm’s broker-dealer and corporate clients, as well as representing boards of mutual funds including the independent directors of a variety of funds managed by AllianceBernstein in connection with litigation driven by the “late trading” and “market timing” investigations conducted by the New York Attorney General’s office beginning in 2003. John Hardiman was resident in the Firm’s London office for nearly five years, where he was co-head of the European Litigation and Arbitration Group, returning to the New York office in 2010.




Fairfield University, B.A., Duke University School of Law, J.D.

United States: Dispute resolution

International arbitration

Within: International arbitration

Headline work for Sullivan & Cromwell LLP included successfully obtaining a $814.9m arbitration award on behalf of BlackBerry in an arbitration against Qualcomm, and representing Centerra Gold in a UNCITRAL arbitration against the Kyrgyz Republic and national mining company relating to disputes over a mining concession. Department head Joseph Neuhaus is ‘outstanding’, and John Hardiman and special counsel Thomas Walsh are also noted. Named individuals are based in New York.

[back to top]

M&A litigation: defense

Within: M&A litigation: defense

Sullivan & Cromwell LLP plays a prominent role in some of the most high-profile hostile takeover cases and shareholder class and derivative actions in the US, and represents clients in industries as diverse as telecoms, energy and healthcare. Brian Frawley in New York leads the M&A litigation team along with John Hardiman and Los Angeles-based Robert Sacks. Sacks successfully defended AT&T in the appeal of a shareholder class action settlement arising from its acquisition of Leap Wireless International in 2013. Frawley’s highlights included the successful representation of former members of the board of Solera, with the dismissal with prejudice of claims of breach of fiduciary duty relating to its $6.5bn sale to Vista Equity Partners. He also defeated a putative class action for Columbia Pipeline Group that challenged its spin-off from NiSource Inc. Michael Steinberg in Los Angeles helped Volcano Corporation secure its motion to dismiss claims filed by former shareholders of Philips Holding USA.

[back to top]

Back to index

Legal Developments worldwide

Legal Developments and updates from the leading lawyers in each jurisdiction. To contribute, send an email request to