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By Osamu Tsukimori and Miho Yoshikawa

TOKYO, July 17 (Reuters) - Japan's trade minister told Tokyo Electric Power Co. <9501.T> on Tuesday to keep its nuclear power plant closed after a quake shook northwest Japan the previous day, causing a fire and a radiation leak at the plant.

The indefinite closure of the Kashiwazaki-Kariwa nuclear power plant, the world's biggest, could leave TEPCO, Asia's largest utility, facing a power crunch as it heads into the peak summer demand period.

Trade minister Akira Amari told TEPCO President Tsunehisa Katsumata early on Tuesday the company should not restart the plant until its safety could be confirmed, a TEPCO spokesman said.

TEPCO has been criticised by central and local government officials for delays in reporting damage at the 8,212-megawatt power plant following Monday's quake, which killed nine people and forced thousands from their homes.

The fire eupted in the plant's transformer, which was made by Toshiba Corp. <6502.T>, Toshiba said.

About 100 drums containing low-level nuclear waste at the plant were knocked over by the quake and the lids of some of them came off, Kyodo news agency reported. TEPCO officials were not immediately available for comment.

The company said earlier that 1,200 litres of radioactive water had sloshed into the sea from the plant but should not affect the environment.

The plant has seven nuclear reactors.

The closure would not mean an electricity shortage this week, but TEPCO is checking the possibility of a shortage next week, the spokesman said.

A hot summer is forecast for Japan this year, and the Federation of Electric Power Companies of Japan said on June 15 that summer peak demand is likely to be 2.9 percent higher than last year.

TEPCO shares closed down 1.1 percent at 3,750 yen, while the benchmark Nikkei average <.N225> closed down 0.12 percent.

(Additional reporting by Mayumi Negishi)

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