Shares in Tokyo Electric Power Co. jumped 15.9 percent in Tokyo Thursday on reports of political progress over the utility's compensation for victims of the nuclear crisis caused by the March 11 quake.
TEPCO shares closed up 81 yen at 590 yen after the Nikkei business daily said ruling and opposition parties had agreed the government will provisionally pay more than half of the compensation costs.
The ruling Democratic Party of Japan accepted a proposal from the main opposition Liberal Democratic Party and its partner New Komeito, it said.
The ruling party was initially reluctant to accept the proposal, but agreed to compromise to secure other concessions from the opposition bloc, which controls the upper house, according to reports.
TEPCO's surge compared with the moderate rise of the Nikkei index, which edged up just 0.04 percent, or 4.49 points, to 10,010.39.
The Topix index of all first section shares at the Tokyo Stock Exchange fell 0.06 percent, or 0.55 points, to 860.11.
TEPCO was also lifted by bullish sentiments towards the firm's plan to bring its stricken Fukushima Daiichi reactors to a cold shutdown by January, market participants said.
Heavy short-covering also supported the shares, they added.
But the company's future remained very much in doubt, analysts said, adding that its shares stay firmly in the realm of day-to-day speculators.