Competition law has been a fundamental area of EU law ever since the establishment of the Treaties of Rome in 1957. 1 EU competition law consists of specific substantive rules, such as the prohibition of anticompetitive agreements and abuse of a dominant position (Articles 101 and 102 Treaty on the Functioning of the European Union (TFEU)), as well as procedural rules laid down in Regulation 1/2003 and various soft law instruments. While the Commission had a central role in the enforcement of Articles 101 and 102 TFEU until 2004, this was fundamentally changed by Regulation 1/2003 in 2004, 2 which delegated enforcement powers to national competition authorities (NCAs) and national courts in order to relieve the Commission of its increasing administrative burden and make enforcement more effective. Article 3 (1) of Regulation 1/2003 imposed an obligation on NCAs to apply Articles 101 and 102 TFEU in parallel with their national competition rules when ‘effect on trade between Member States’ can be established. Accordingly, EU competition law is today enforced by the EU Commission and 28 NCAs, in a multi-level governance system composed of EU and national procedural laws. The NCAs and Commission have concurrent jurisdictions and there are neither territorial limitations to their enforcement powers nor a prohibition of parallel proceedings between

1 The Treaties establishing the EEC and Euratom in 1957 were signed by Belgium, France, Germany, Italy, Luxembourg and the Netherlands in Rome and are therefore also referred to as the Treaties of Rome. 2 Council Regulation (EC) 1/2003 of 16 December 2002 on the implementation of the rules on competition laid down in Articles 81 and 82 of the Treaty [2003] OJ L1/1.