BEIJING: China, one of the world's top sugar buyers, imported 550,000 tonnes of the sweetener in April, up 102 percent from a year before, driven by strong demand for cheap overseas supplies. That volume was widely expected by the industry as global prices are close to a six-year low and that has spurred buying by refineries in China, where prices are much higher. The price gap between overseas and domestic sugar is more than 1,000 yuan ($161) per tonne, trade sources say. While global prices are under pressure from surplus stocks, Chinese prices are being propped up by concern over a significant decline in domestic output as well as reports of government restrictions on imports. China's top sugar-growing region, Guangxi, may see acreage fall 11.5 per cent in the 2015-16 season, indicating a further drop in sugar output after production declined by around a quarter this year, an official said last month. "It's not easy to see room for the price to drop, based on expectations for output and next year's crop," said a trader who declined to be identified. While there has been much talk of Beijing restricting sugar imports to support struggling domestic mills, shipments so far this year have outpaced expectations, with arrivals at 1.55 million tonnes in the first four months, up 36.5 per cent on the same period last year. Refineries have already booked close to 1.9 million tonnes of out-of-quota imports, however, and may scale down their buying in coming months to comply with an unofficial agreement made last year to restrict 2015 imports to this level, the trader said. But some analysts believe refineries will be unable to ignore attractive margins and that China's 2015 imports could come close to the record 4.5 million tonnes reached in 2013.