High Quality Content by WIKIPEDIA articles! The Tokyo Electric Power Company, Incorporated, also known as Toden or TEPCO, is an electric utility servicing Japan's Kant? region, Yamanashi Prefecture, and the eastern portion of Shizuoka Prefecture. This area includes Tokyo. Its headquarters are located in Chiyoda, Tokyo and international branch offices exist in Washington, D.C. and London. This company is the largest in Japan, and the 4th largest electric power company in the world.(The 1st-E.ON, 2nd-Électricité de France, 3rd-RWE) The total amount of electricity it annually sells is as same as the amount Italy uses in a year. The share of this company in Japanese electric market is approximately one-third. Though there are 10 electric utilities in Japan, the TEPCO is in a leading position in Japanese energy industry.