The low-cost Irish airline, Ryanair, announced on Tuesday that it has placed an order for 300 Boeing 737-MAX-10s.
Half of the planes - 150 - are firm and the remaining 150 are options.
They are to be delivered between 2027 and 2033, for a list price "valued at more than $40 billion," according to a statement from Ryanair.
This is the largest order ever placed by an Irish company for American manufactured products, Ryanair said.
Give its size, the deal "will be submitted to shareholders for approval" at a Ryanair general meeting on 14 September, the Irish airline said.