One of the current energy policy's goals in the European Union (EU) is the exchange of knowledge and experience between the EU-15 member states and the new as well as the candidate countries in issues regarding the development of Renewable Energy Sources and the promotion of Energy Efficiency(EE). Nowadays, the liberalization of energy markets and the deterioration of the climate, in combination with the non-stop crude oil price increase, have had a decisive influence on the development of the above sectors. In addition, one of the most important elements for the renewable energy and EE development is the enhancement of energy producers by renewable energy and Energy Service Companies (ESCOs), respectively. These companies' success is based on the formulation of a modern environment in each EU member state. However, the environment in the new and candidate member states is less mature than the environment in the EU-15 member states, as it is still in its development phase. In this context, the main aim of this paper is to present a "multi-dimensional" decision support methodology for the formulation of modern energy companies' operational environment in the 13 new and candidate member states of the EU. (c) 2006 Elsevier Ltd. All rights reserved.