Contents1 Introduction: EU Competition Law and Energy Markets 1Adrien de Hauteclocque and Christopher JonesPART I THE DEFINITION OF THE RELEVANT MARKET2 Introduction: the definition of the relevant market 5Léna Sandberg, Yannis Ioannidis and Pilar D'Ocon3 The relevant product market: electricity 9Léna Sandberg, Yannis Ioannidis and Pilar D'Ocon4 The relevant geographic market: electricity 44Léna Sandberg, Yannis Ioannidis and Pilar D'Ocon5 The relevant product market: gas 105Léna Sandberg, Yannis Ioannidis and Pilar D'Ocon6 The relevant geographic market: gas 122Léna Sandberg, Yannis Ioannidis and Pilar D'OconPART II AGREEMENTS, CONCERTED PRACTICES, AND ABUSE OF DOMINANCE:ARTICLES 101 AND 102 TFEU7 Introduction: agreements, concerted practices, and abuse of dominance: Articles 101 and 102 TFEU 134Lars Kjolbye8 Horizontal agreements 148Lars Kjølbye9 Vertical agreements 199Lars Kjølbye10 Article 102 TFEU: abuse of a dominant position 246Adrien de HauteclocquePART III MERGER CONTROL11 Introduction: merger control 304Valérie Landes12 Jurisdiction: when does a merger fall under the merger regulation? 308Valérie Landes13 Substantive assessment of concentrations 354Valérie Landes14 Merger control in the electricity and gas sectors 373Valérie Landes15 Remedies in energy mergers 451Valérie LandesPART IV STATE AID16 Introduction: state aid 491Leigh Hancher17 Coal and nuclear aid 494Leigh Hancher18 State aid in the TFEU: notion of aid 529Daniel Vasbeck19 Compatible state aid in the energy sector 579Francesco Maria Salerno20 State aid procedure 655Daniel VasbeckPART V ARTICLE 106 TFEU21 Special and exclusive rights 693Leigh Hancher.