Shares of Tokyo Electric Power Co. Holdings Inc. surged Wednesday as a heat wave in Japan boosted power demand in the capital.
The Japanese power utility 9501, +5.27%, also known as Tepco, rose as much as 6.2% before paring gains to trade 4.7% higher at 576 yen ($4.23). Its one-week advance stands at 23%, taking the stock to its highest level in three years.
The share-price rise comes as Tokyo’s electricity grid is under increasing strain due to higher cooling and air-conditioning demand amid a heat wave.
Tepco has issued a warning saying that the supply-demand balance in its service area on Wednesday is expected to be particularly severe from 3 p.m. to 8 p.m. local time because of high temperatures.
Japan’s Ministry of Economy, Trade and Industry has also issued an advisory calling for households and businesses to save electricity while being cautious about the risk of heatstroke.
Write to Yongchang Chin at yongchang.chin@wsj.com