European plane manufacturer Airbus said Tuesday it had received a firm order from US low-cost Frontier Airlines for 12 medium-haul A320 family aircraft in a deal worth $1.3 billion (1.2 billion euros) at list prices.

The order for 10 A321 and two A320 aircraft are for planes equipped with current-generation engines, but will have wing-tip fins that help reduce fuel consumption by four percent.

"This announcement paves the way for us to grow, modernise and renew our fleet while helping us build a strong foundation for the future," Frontier Airlines's President Barry Biffle said in a statement.

This is the second time in less than a year that the airline has ordered the A321, the largest version in the A320 family of single-aisle aircraft.

The Denver-based airline now has 101 Airbus single-aisle aircraft on order.