The European Union's Third Energy Package is a legislative package for an internal gas and electricity market in the European Union. Its purpose is to further open up the gas and electricity markets in the European Union. The package was proposed by the European Commission in September 2007, and adopted by the European Parliament and the Council of the European Union in July 2009. It entered into force on 3 September 2009.
Core elements of the third package include ownership unbundling, which stipulates the separation of companies' generation and sale operations from their transmission networks,[1]: Article 9 and the establishment of a National regulatory authority (NRA) for each Member State,[1]: Chapter IX and the Agency for the Cooperation of Energy Regulators (ACER) which provides a forum for NRAs to work together.[2]