BEIJING -- China National Offshore Oil Corporation (CNOOC), China's largest offshore oil producer, has announced that operations have begun at the country's first overseas large liquefied natural gas (LNG) supply base.

The move is important in developing China's natural gas industry and securing clean energy supply to China, according to the CNOOC.

The LNG supply base, located at the Queensland Curtis LNG project in Queensland, Australia, will supply CNOOC with 8.6 million tons of LNG annually for 20 years, said the company.

CNOOC signed LNG agreements with BG Group to purchase interests in the Queensland Curtis LNG project in Australia in 2010 and 2013, making it the project's second-largest investor and beneficiary.

CNOOC imported more than 13 million tons of LNG last year, accounting for 72 percent of the country's total LNG imports in 2013, official data showed.

By the end of May 2014, CNOOC had built and put six LNG receiving terminals into operation in China's coastal regions.