Tokyo Electric Power Co., forced to shut the world's biggest nuclear power plant, has asked the government for permission to delay maintenance at one of its reactors this summer to avert a shortage during peak season.

The utility asked the trade ministry to put off the regular inspection at its No. 3 Fukushima Daini reactor by 17 days to Sept. 6, it said in a statement today. All of Japan's nuclear operators are obliged by law to shut reactors for inspections every 13 months to ensure safety.

Tokyo Electric has increased power generation from oil- and natural-gas fired plants from July to September to cover a supply shortfall caused by the closure of its Kashiwazaki Kariwa plant following an earthquake in July last year.

Vice President Takashi Fujimoto on July 3 said the company will secure sufficient supplies to avoid blackouts in Japan's capital and surrounding region. The utility can supply as much as 66.7 million kilowatts in August, the hottest month, to meet demand it estimated at 61.1 million kilowatts.

The utility will operate its 10 nuclear reactors, with total generation capacity of 7,996 megawatts, in Fukushima prefecture, north of Tokyo, throughout the summer, Shogo Fukuda, a company spokesman, said by phone today.