The Third Internal Market package marks a watershed in the EU's efforts to introduce effective liberalisation of its electricity and gas markets. A real understanding of this very complicated legislative package is vital for all energy companies operating in the EU, as well as major energy purchasers and advisors. This new and fully updated fourth edition includes indepth contributions on a common electricity and gas wholesale market, third party access, unbundling of TSO's and DSO's, National Regulatory Authorities, ACER, regulation of crossborder electricity exchanges, Gas regulation, Retail market development and public service objectives, derogations and exemptions, common network rules, security of supply, reporting and review of the Directives, implementation and entry into force, the internal energy market and neighboring countries and an introduction to the energy market of the US. The fourth edition of this highly acclaimed and leading title on this subject is written by the key Commission officials and practitioners.