C-439/06, 22 May 2008. Considered whether it was permissible under European law for national legislation to allow energy monopolies in certain circumstances. A utilities company (C) asked the European Court to rule on the legality of the arrangements for energy supply at Leipzig airport. Electricity was supplied by onsite power generation only, and the operations therefore provided third parties with no opportunity to enter into supply arrangements. German national law permitted monopolised energy supply under certain conditions, and was used in the arrangement. C asked the European Court to rule on its compliance with EU Directive 2003/54/EC Article 20(1). "Held": The German law of energy management exempted operators, in certain conditions, from the requirement to provide access to geographically and logistically closed systems. However this arrangement was precluded by the relevant Article and Directive of European law and the arrangement was therefore not permissible under European legislation. Preliminary ruling made.