Monarch Airlines has finalised its order for 30 737 MAX 8 aircraft, worth more than $3.2bn (£1.9bn).
The announcement was first made at the Farnborough Air Show in July, when the airline selected Boeing and marked the beginning of its transition to an all Boeing single-aisle fleet.
The order also includes options for an additional 15 737 MAX 8s with Monarch expected to take delivery of the first of its new aircraft sometime in 2018.
The 737 MAX has accumulated 2,325 orders to date from almost 50 global customers, according to Boeing.
Last month, 90 per cent of Monarch was sold to private equity firm Greybull Capital for £125m ($200m).