Tokyo: China overtook Japan as the world's second-largest crude oil importer in May, according to data yesterday that showed an 8 per cent rise in purchases by Japan, where power plants have been forced to burn more crude.

Japan's customs-cleared crude oil imports in May rose 8.0 per cent to 18.525 million kilolitres (3.76 million barrels per day) from a year earlier, preliminary data of Japan's Ministry of Finance showed yesterday.

China, which surpassed Japan as the world's No. 2 oil consumer, imported 16,198,188 tonnes (118.25 million barrels, or 3.81 million bpd) of crude in May, up 25 per cent from a year ago, customs data showed on Monday.

"It's a symbol of the era," said Akira Kamiyama, derivatives trader at Mitsui & Co. "Japan's imports will be capped, but China's imports will grow fast, with no end in sight."

The increase in Japanese imports comes amid the prolonged shutdown of the world's biggest nuclear power plant, operated by Tokyo Electric Power Co. (Tepco), after a major earthquake last July.

The shutdown doubled Tepco's demand for direct-burning crude and fuel oil for thermal generation.

But overall, Japan's domestic oil sales have been shrinking at around 4 per cent a year since 2006, and the government expects the slide to continue as record high prices spur industries to shift to electricity or alternative power sources.