Air China, one of the three major civil aviation companies in the country, said Thursday that it has ordered 20 Airbus A320 planes to promote its fleet capacity on growing demand.

In a statement to the Shanghai Stock Exchange, Air China said that the planes of the 1.63-billion U.S. dollars deal would be delivered in stages from 2011 to 2014.

Air China expected to elevate its fleet capacity by 5 percent via this transaction, said the statement, adding that the move mainly aimed to support the hub-building in Chengdu, strengthen the fleet capacity in the southwestern China, and help promoting the flights in eastern China to a certain degree.

Air China will pay by cash by instalment, according to the statement.

Air China, China Southern and China Eastern are the country's top three air carriers.