China’s ICBC Leasing has signed a firm order with Airbus covering a total of 50 A320-family narrowbodies, including 30 current-generation A320s and 20 A320neos. Worth as much as $4 billion based on list prices, the deal comes as China continues to exert pressure over Europe’s emissions trading scheme (ETS) by withholding final approval of other Airbus sales in the People’s Republic.

One of a series of Europe-China pacts signed in the presence of visiting German Chancellor Angela Merkel and Chinese Premier Wen Jiabao at the Great Hall of the People in Beijing, the deal accompanies a $1.6 billion framework agreement to extend the contract for A320 production in Tianjin, according to China’s Xinhua news agency.

“The order indicates that leasing companies are playing a more important role in the aviation sector,” said Li Xiaopeng, senior executive vice president of ICBC and chairman of ICBC Leasing.

The provision for 20 A320neos makes ICBC the first Chinese customer for the re-engined Airbus narrowbody, scheduled for introduction in 2015. ICBC has yet to commit to an engine choice. Airbus offers an option of either the Pratt & Whitney PW1000G or CFM Leap-1A for the Neo.

By the end of July, more than 700 A320-series airplanes were flying with 15 Chinese airlines.