Chair Professor of Administrative Law, University of Buenos Aires (2007- ); Professor of Administrative Law, University of Buenos Aires (1988-2007); Associate Professor of Administrative Law (1984-1988); Chair Professor of Economic Regulation, Catholic University of Buenos Aires (1997- ); Chair Professor of Public Utilities, Universidad Austral (1991-2007); Visiting Scholar, UC. Berkeley (1987); Partner, R. & G. Tawil (1983-1987); Secretary (equivalent to federal district judge), Argentina´s Federal Supreme Court of Justice (1989-1991); Commissioner, Argentina´s Securities & Exchage Commission (1991-1993); Senior Partner, Head of International Arbitration, Administrative Law and Regulatory practices; M. & M. Bomchil (1993-2018);