European commercial aircraft builder Airbus Thursday said JetBlue Airways Corp. has finalized a firm order for 40 medium-haul A320neo single-aisle aircraft that was previously announced at the Paris Air Show in June.

The A320neo is a re-engined, more fuel-efficient version of Airbus's best-selling A320 that will be entering service with customer airlines starting in 2016.

Airbus said JetBlue hasn't yet announced its selection of engine.

It said JetBlue has also decided to convert 30 pre-existing orders for A320s to larger A321 models.

JetBlue has a total of 92 A320 family aircraft on order with Airbus - 40 A320neos, 30 A321s, and 22 A320s.

On the basis of Airbus's list prices, the 40 A320neos are worth more than US$3.6 billion.