Quake-hit Japanese electricity utility TEPCO on Tuesday announced its first price rise in more than 30 years, putting up industrial tariffs by 18 percent in the wake of the Fukushima nuclear disaster.

The firm has not increased prices since a 52 percent hike in 1980, instead cutting them on several occasions.

But the crisis at its Fukushima atomic power station -- the world's worst nuclear accident in 25 years -- has seen the firm bailed out with huge sums in public funds and most of Japan's nuclear plants shut down.

Japan's largest utility has had to increase its use of fossil fuels.

"Fuel costs have greatly increased as a result of the company's efforts to maintain its power supply capability," TEPCO said in a statement, which "the company cannot afford despite its thorough cost-cutting effort".

Large business user rates will go up by 18.1 percent in April, and those for small- and mid-size customers by 13.4 percent.

TEPCO said it may also hike domestic user tariffs, which would need government approval and would likely provoke a furious public reaction.