Air China has emerged as the Chinese customer behind an agreement to acquire 10 Airbus A350 aircraft, as well as 10 A330s.
The airline is to take delivery of the A350s in stages from 2018 to 2020.
Air China adds that it expects to introduce the A330 twin-jets between 2013 and 2015.
It has detailed its plans following the Chinese Government's signing of an agreement, earlier this month, covering acquisition of 102 Airbuses.
That agreement included 10 A350s but did not identify the carrier for which they were bound.
Air China has not stated the variant of A350 it plans to take, nor has it identified whether the A330s will be -200s or -300s.
It has given a value of just under $4.5 billion for the aircraft purchase, based on earlier list prices, but states that it has been granted "significant price concessions".
A350s are only available with Rolls-Royce Trent XWB powerplants. Air China has not given an engine selection for the A330s but its current A330 fleet is powered by Rolls-Royce Trent 700s.