China’s state-owned oil companies are likely to stop imports of refined products such as diesel and petrol next month after a nine-month buying spree that has left stockpiles overflowing, one of Asia’s largest refiners said.

“Since China started whipping up imports in November last year, 25 per cent to a third of our diesel exports have gone there,” said Wilfred Wang, chairman of Taiwan’s Formosa Petrochemical (FPCC). “But this market will disappear next month.”