Europe

The European Union (EU)

http://europa.eu/pol/ener/index_en.htm
Activities of the European Union - Energy section

Eurelectric

http://www2.eurelectric.org/Content/Default.asp
The Union of the Electricity Industry

Eurogas

http://www.eurogas.org/
Eurogas is a non profit organisation governed by the Belgian law. The offices are located in Brussels.

GEODE

http://www.geode-eu.org/ 
European independent distribution companies of the European Union.

Agency for the Cooperation of Energy Regulators (ACER)

http://www.acer.europa.eu/portal/page/portal/ACER_HOME
Working towards a Single Energy Market to the benefit of all EU consumers.

Council of European Energy Regulators (CEER)

http://www.energy-regulators.eu/portal/page/portal/EER_HOME/EER_ABOUT
It seeks to facilitate the creation of a single, competitive, efficient and sustainable EU internal energy market. 

DG ENER

http://ec.europa.eu/energy/index_en.htm
European Commission Energy Directorate