Scientific Essay from the year 2014 in the subject Law - Civil / Private, Trade, Anti Trust Law, Business Law, grade: 2.0, Free University of Berlin, course: Master degree, language: English, abstract: Achieving a genuine internal energy market is a priority goal for the European Union. The internal energy market is made up of the European gas and electricity markets. It has been the subject of several successive sets of directives and regulations, grouped into “legislative packages”. There have been three such packages up to now, put together by the European Parliament and the European Union Council, which establish common rules for the internal energy market for all Member States. In 2007, the European Commission drew up an assessment report on the internal market based on a sector-specific survey of the gas and electricity markets. It concluded that there were still numerous deficiencies preventing both consumers and the industry from fully reaping the benefits of open national markets. The Commission then announced that a 3rd legislative package would be introduced to reinforce the rules so far adopted. The aim of 3rd Energy Package which was adopted in 2009 was to make the energy market fully effective and to create a single EU gas and electricity market. This would help to keep prices as low as possible and increase standards of service and security of supply. The most important proposal of the "3rd Energy Package" is "ownership unbundling" - separating the operation of gas pipelines and electricity networks from the business of providing gas or generating power. The purpose of ownership unbundling is to promote an open and transparent market, non-discriminatory access to networks and a level playing field. The idea is to combat cross-subsidization between generation/supply and networks, including exchange of strategic information, to ensure both undistorted competition in electricity and gas markets and sufficient investment in networks. Therefore, in order to value the importance of the Third energy package for ensuring effective competition the principles of ownership unbundling should be precisely discussed. Thus in the first part of this paper general information about Third Energy Package will be given and brief description of principles, benefits and deficits of the ownership unbundling will be discussed in the following parts respectively. The conclusion part answers the question whether existence of the ownership unbundling, as a main part of the 3rd Energy Package is sufficient to ensure effective competition or not.