High Quality Content by WIKIPEDIA articles! Natsionalna Elektricheska Kompania NEK is the Bulgarian national electricity distributing company also being the second largest company in Bulgaria. At the end of 2005 NEK had 31 hydro power plants with a total installed capacity of 2,563 MW and an electricity generation capacity of 3,544 GW·h. The company also operates 14,610 km of overhead lines and has 279 substations; the total amount of electricity sales in 2005 were 34,171 GWh. It is a subsidiary of Bulgarian Energy Holding EAD, together with the gas company Bulgargaz, NEK EAD, Kozloduy nuclear power plant, Maritza-Iztok II thermal power plant, and the Mini Maritza Iztok (Maritza Iztok mines). In November 2009, the Bulgarian Government decided to unbundle the transmission system operator ESO and to list NEK at the Bulgarian Stock Exchange - Sofia.