US aircraft maker Boeing Co said that by 2020, it will deliver its first B777X aircraft, the latest addition to its family of twin-aisle airplanes, and a more fuel-efficient and powerful version of the current B777-300ER. The company said it is bullish on China's demand for wide-body planes, fueled by China' growing international flights market.

Currently, the B777X has 340 orders and commitment orders from eight global customers, but Chinese airlines haven't ordered any yet.

"Air China, China Eastern Airlines and China Southern Airlines still have a large number of B777-300ER aircraft orders not delivered yet. They are expected to start ordering B777X in the next five years," said Darren Hulst, managing director of marketing at Boeing Commercial Airplanes Northeast Asia.

"The B777X model can help airlines to further extend their flight networks and support extra long-haul routes, such as direct flights between Beijing and Panama, and other Latin American countries."

At the moment, about 100 aircraft retire every year globally, and by 2021 to 2022, there will be about 200 aircraft retiring every year, according to Boeing, which should create a lot of business opportunities in the market for new jets.

Boeing said the B777X family will include the B777-8, which has 350 to 375 seats and competes directly with the A350-1000 of European giant Airbus, and B777-9, with 400 to 425 seats and is in a class by itself. The B777X family aircraft will be mainly operated on routes that connect major air transportation hubs.

In the next 20 years, the global market will need about 3,000 to 4,000 medium and large wide-body aircraft, and China's wide-body fleet will require 1,670 new airplanes over the period, according to an earlier Boeing forecast.

"China's continuous economic growth, significant investment in infrastructure, growing middle class and evolving airline business models support this long-term outlook," said Randy Tinseth, vice-president of marketing at Boeing Commercial Airplanes.

In the first half of this year, Hainan Airlines, China's largest private airline, transferred 1.86 million passengers on international routes, surging 97.8 percent year-on-year. The number of passengers transferred by China Southern, China Eastern and Air China on their international flights grew 7.48 percent, 1.7 percent and 1.5 percent, respectively, according to the Civil Aviation Administration of China.

Eric Chen, Airbus China president and CEO, said the booming growth of international flights from China, especially long-haul routes, required wide-body aircraft. He said the A350 aircraft is suitable for those airlines with complete international flight networks.