Beijing: China's net imports of crude oil fell to an eight-month low in June amid refinery maintenance and slowing energy demand in the fastest-growing major economy.

Net imports last month fell 10 per cent from a month earlier and 12 per cent from a year earlier to 19.43 million metric tonnes, or about 4.7 million barrels a day, according to Bloomberg calculations based on data released Sunday by the General Administration of Customs.

That's the lowest since October, the data show, as the nation imported 19.7 million tonnes and exported 270,000 tons of crude.

Some refineries in China, including PetroChina Co's largest facility at Dalian in the northeast, shut for routine maintenance in June, leading to a decline in demand for crude oil. About 600,000 barrels a day of capacity were taken offline last month, Brynjar Eirik Bustnes, a Hong Kong-based analyst at JPMorgan Chase & Co, said.

"We were expecting imports to fall even more but looks like they were doing some stockpiling for July," Bustnes said. "The slowing economy would have had an effect on the fall in imports as well."

China may import about the same volume of crude oil this month with an estimated 700,000 barrels a day of refining capacity expected to be offline for maintenance, he said.

The world's second-biggest importer of oil bought seven per cent more crude oil in the first half from a year earlier at 126.2 million tonnes, according to data on the customs website.

China paid an average $110 for each barrel of crude bought in June compared with $115 in May, according to Bloomberg calculations.

The cost of crude imports averaged $103 a barrel in the first six months.

Net imports of fuel, including gasoline and diesel, rose to 1.36 million tonnes last month from 930,000 tonnes in May, according to the data.