Qatar Petroleum International, a unit of the emirate's state-run oil company, plans to build two petrochemical plants costing about $9.8 billion in Asia by 2015 to tap demand in the world's fastest-growing region.

Qatar will partner China National Offshore Oil Corp (CNOOC) and a Chinese petrochemicals maker to construct a $5.8 billion plant in China's Hainan province, Chief Executive Officer Nasser al-Jaidah said in an interview in Tokyo. Another project in Vietnam will cost as much as $4 billion and both ventures will use Qatari liquefied petroleum gas to produce chemicals, he said.

"There is huge potential for growth in Asia, especially China," al-Jaidah said. "We can hit two birds with one stone - tap the markets and exit our product," he said, without disclosing Qatar's share of investment in the venture.