China Southern Airlines will buy 20 A350-900 aircraft from Airbus in a deal valued at about US$6 billion, the company said in a filing to the Hong Kong stock exchange on Wednesday.

The company said it will buy the jets, which have a catalog price of US$298.9 million, with deliveries starting from 2019. Discounts are customary for such large orders, it said.

The state-owned carrier, which recently agreed to sell a sell a minority stake to American Airlines, plans to expand its fleet to 1,000 by 2020 from 700 now, according to Bloomberg, which cited Chairman Wang Changshun.  China Southern and its units have ordered more than US$15 billion of new aircraft from Boeing and Airbus since 2015, Bloomberg said.