Air China is to buy 20 passenger planes from Airbus in deal worth 4.49 billion US dollars, the airline said in a statement filed with the Hong Kong stock exchange on Thursday.

China's leading carrier said it would acquire 10 Airbus A330 and 10 Airbus A350 series aircraft from the France-based aviation consortium, for which it would pay in cash instalments.

The A330s will be delivered in stages from 2013 to 2015 and the A350s from 2018 to 2020, Air China said in its statement.

Airbus had granted Air China "significant price concessions" for the aircraft and the purchase will be funded by business operations, bank loans, and "other financing instruments," the airline said.

Air China estimated the acquisition would increase the capacity of its fleet by 18.6 percent.

The acquisition will "optimise the fleet structure of the Company and is in line with the market requirements (and) will deliver more cost-efficient performance and provide comfortable services to passengers."

Air China serves more than 120 domestic and international destinations with its fleet of more than 260 Airbus and Boeing jet aircraft, according to state media.

"Air China has ordered more than 200 Airbus and Boeing planes so far. In 2009, Air China carried 41.28 million passengers," Xinhua news agency reported, quoting the airline's website.

The statement follows several major acquisitions by Chinese carriers in recent weeks, including China Southern Airlines' 3.78 billion-dollar deal for 36 Airbus planes.

The China Southern deal, for A320s and A330s between 2012 and 2015, was announced as China's President Hu Jintao arrived in France for three-day state visit.

This week, Air China, China Southern and China Eastern -- China's three largest airlines -- were among the reported buyers of 100 C919 airliners, the 190-seat jet built by the Commercial Aircraft Corporation of China (COMAC).

COMAC announced the deals at the Zhuhai Airshow in the southern province of Guangdong, challenging industry giants Airbus and Boeing in what is expected to become the world's largest aviation market.

Airbus rival Boeing said earlier this month it expected China's civil aircraft fleet to triple over the next 20 years.

"China is one of the world's fastest growing and dynamic aviation markets, driven by the urbanisation of China, the growth of its economy and an ever increasing personal wealth," Randy Tinseth, vice president of marketing for the US aerospace giant, told a briefing in Beijing on Tuesday.

Chinese airlines will need 4,330 new jets valued at 480 billion dollars over the next two decades, compared with global demand of 30,900 units during the period, he said.

Last week, the head of China's civil aviation administration offered an even more bullish forecast, saying the country would have up to 5,000 aircraft to transport passengers and cargo by 2015, according to state media.

In September, Hong Kong-based carrier Cathay Pacific said it had confirmed an order for 30 long-range A350 Airbus aircraft with a book price of 7.82 billion dollars -- the biggest single order in the carrier's history.