The China National Petroleum Corporation (CNPC), parent of PetroChina, announced Thursday it has signed a framework agreement with Uzbekistan oil company Uzbekneftegaz to buy 10 billion cubic meters of natural gas annually.

CNPC general manager Jiang Jiemin signed the agreement Wednesday with Uzbekneftegaz board chairman Ulugbek Nazarov in the Uzbekistan capital Tashkent, a statement on the CNPC website said Thursday.

The agreement was signed during Chinese President Hu Jintao's visit to the country. Hu is attending the 10th annual summit of the Shanghai Cooperation Organization on June 10-11 in Tashkent.

The statement did not provide details on the value of the purchase agreement nor on a specific date when the supply would be initiated.

The two sides would first work to connect Uzbekistan's natural gas transmission system with the China-Uzbekistan natural gas pipeline, the statement said.

The China-Uzbekistan gas pipeline is part of the larger 1,833-kilometer China-Central Asia gas pipeline that opened in December 2009, linking gas fields in Turkmenistan, Uzbekistan, and Kazakhstan to northwest China's Xinjiang.