William T. Allen is of counsel to the firm. In that capacity, he consults on matters of corporation law and corporate governance with members of the firm and their clients. Since 1997 Allen has served as the Jack H. Nusbaum Professor of Law & Business at New York University where he is also the founding Director of the NYU Pollack Center for Law & Business, a center designed to serve as an academic bridge between the NYU School of Law & the NYU Stern School of Business.

From 1985 to 1997 William Allen was the Chancellor of the Delaware Court of Chancery. As Chancellor, he wrote hundreds of corporate law judicial opinions. Notable among these were the Caremark case, which addressed the duty of corporate directors to monitor corporate legal compliance; the Time-Warner case that addressed the board's ability to resist a hostile offer while it was seeking to effectuate its own business plan; and the Blasius case, which announced a heightened standard of judicial review when director action sought to interfere with a shareholder vote.

While a judge, Allen taught corporation law and corporate governance as a Visiting Professor at Stanford Law School and the University of Pennsylvania Law School. In 1996 he served as Rabin Lecturer at Yale Law School.

Judge Allen writes, consults and lectures on corporate law, mergers and acquisitions and corporate governance. His writings on corporate law and governance are numerous, including the widely adopted student text "COMMENTARIES AND CASES ON THE LAW OF BUSINESS ORGANIZATION," co-authored with Harvard Law School professors Reinier Kraakman and Guhan Subramanian (3rd ed 2009, Wolters Kluer Law & Business Publishing). Allen received his B.S. from New York University, his J.D. from the University of Texas and the honorary doctorate degree LL.D. from Dickinson Law School. Judge Allen is a member of the American Law Institute and the American Academy of Arts & Sciences, among other professional organizations.