United Airlines Holdings Inc. will buy 110 more aircraft that will be delivered starting in 2028, making an aggressive bet on growth and future travel demand globally.

United converted existing options it held into firm orders on Tuesday for 50 Boeing Co. 787-9s to be delivered from 2028 through 2031 and for 60 Airbus SE A321neos for delivery between 2028 and 2030. The planned double-digit purchase of Airbus jets was reported earlier by Bloomberg.

The Chicago-based airline also secured new options for additional planes at the end of the decade, it said in a statement.

United has been one of the largest aircraft buyers this decade and has said it plans to add about 800 narrow- and widebody planes over the next ten years or so as it hires more than 10,000 pilots. The latest purchases build on a multi billion-dollar deal with Boeing for 100 planes and 100 options that was placed in December.

“I’m convinced our strategy is the right one as we continue to add new, larger aircraft to take full advantage of our growing flying opportunities both internationally and domestically,” Chief Executive Officer Scott Kirby said in the statement.

Carriers across the world are locking in delivery slots for new aircraft as Airbus and Boeing struggle to keep pace with demand spurred by a rebound in air travel. Backlogs at both planemakers now stretch past the end of this decade, and United’s latest orders come in an effort to ensure a steady flow of aircraft.