China National Offshore Oil Corporation (CNOOC), the country's third-biggest oil producer, plans to start operating its first giant refinery in Guangdong next month to meet rising fuel demand in the southern province.

The company is now testing the 240,000 barrel-a-day Huizhou refinery in Guangdong, according to two CNOOC officials who declined to be named. The refinery's start-up was delayed from the end of last year due to market uncertainty, one of the officials said.

Construction at Huizhou began in late 2005. It is CNOOC's first large oil refinery project, involving a total investment of over 20 billion yuan.

The company plans to boost the annual capacity of the refinery to 22 million tons from the present 12 million during the period of the 12th Five-Year Plan (2011-15).