Airbus has landed its biggest-ever order with budget airline investor Indigo Partners signing a deal to buy 430 jets.

The agreement, for Airbus's best-selling A320 family of small airliners, is worth a $49.5bn at list prices.

Although the order - for 273 A320neos and 157 A321neos - has a list value of almost $50bn, Indigo is unlikely to pay anywhere near as much. The A320neo is priced at $108m and the larger A321neo at $127m but manufacturers offer large discounts on jets. Such a massive order is likely to mean a bigger than normal price reduction.

As analysts digested the order - almost twice the size of the company's previous largest deal, a $26bn sale of 250 A320s to an Indian budget airline - Mr Leahy revealed another sales success. Dublin-based lease company CDB Aviation confirmed MoUs for 90 A320neos.

The order takes Airbus's backlog of work on the A320 family of jets to almost 6,000 - the equivalent of almost a decade's work. The company has delivered nearly 8,000 of the aircraft since they were introduced 30 years ago.