China National Offshore Oil Corp. (CNOOC), the nation's third largest oil producer, will spend 6.6 billion dollars to nearly double the capacity of a major refinery project, state media said Friday.

    CNOOC plans to boost its oil refinery in Huizhou, a city in south China's Guangdong province, to 22 million tonnes a year by 2015 from the present 12 million, the China Daily said.

    It will also add to the refinery a new plant that will make ethylene, a widely used compound, with a capacity of one million tonnes a year, the report said.

    "The Huizhou project will further increase the energy supply in the Pearl River Delta (in Guangdong), one of China's economic powerhouses," the newspaper quoted an unnamed source at the company as saying.

    Construction on the Huizhou project started in late 2005, and it is expected to come on-stream in October, the report said.

    It is CNOOC's first large oil refinery project in the country and the first phase had a planned total investment of more than 20 billion yuan (2.9 billion dollars), it added.

    The company also has a 50-50 joint venture petrochemical project in Huizhou with Anglo-Dutch oil giant Shell.

    CNOOC's listed arm CNOOC Ltd. said on Wednesday that its first-half net profit rose by 89.3 percent year-on-year to 27.5 billion yuan on high oil prices and solid operational performance, the China Daily reported.