Despite the fact that the telecommunication sector is heavily regulated in the EU, several important telecommunication-specific competition law issues have emerged over the past two years. In its recent enforcement practice, the Commission gave important competition law guidance to the national regulatory authorities as to how to define the relevant markets in the telecommunication sector. In specific competition cases, the Commission and the European Courts issued various important statements on the relationship between ex-ante regulation and ex-post review. Apparently, the consideration of the incentives to invest is the main focus of the recent competition law enforcement in telecommunications. The spread of network-sharing agreements in the sector is increasing due to the higher requirements for investment into communication infrastructure (e. g. 4G and FTTx). The Commission resists being more lenient with the concentration of national telecommunication markets by not allowing the consolidation efforts to overcome anticompetitive effects in merger control, as it was expressed in the Hutchison/Orange Austria merger and it is reflected by the ‘Connected Continent’ legislative package as well.