Head of Gas Department ACER – Agency for the Cooperation of Energy Regulators Mr. Dennis Hesseling joined the EU Agency for the Cooperation of Energy Regulators ACER as Head of the Gas Department in December 2012. He is responsible for the Agency’s gas activities regarding network codes, infrastructure, and market monitoring. He is also the Agency’s representative to the Energy Community Regulatory Board. Before joining ACER, Mr. Hesseling worked as Head of Unit in the Competition Department of the Netherland Competition Authority NMa (ACM), responsible for merger control and antitrust enforcement in the Dutch energy, telecommunications and media sectors. Prior to that, he worked in the NMa’s Energy Regulation department from 2002 on, mainly on gas issues. From 2000 he worked as a management consultant for McKinsey & Company in Brussels, providing strategic and operational advice to postal companies and banks. Mr. Hesseling holds a PhD in Mathematics from Utrecht University, the Netherlands. He received additional training at McKinsey, business school IMD (Lausanne), and the Dutch programme for prospective top civil servants. Mr. Hesseling trained energy regulators and competition authorities in Romania, Bulgaria, the Ukraine, Turkey and Vietnam, and political parties in various African countries.