United Airlines Holdings Inc (UAL  ) has announced orders for 110 more aircraft for delivery beginning in 2028.

The order includes 50 Boeing Company (BA  ) 787-9 and 60 Airbus SE (EADSY  ) A321neo aircraft.

The orders build on the early success of United Next strategy. A key component of the plan is growth in gauge, essentially flying larger planes with more available seats on the same route.

United converted previous options and purchase rights into firm orders for 50 787-9s for delivery between 2028 through 2031 and 60 A321neos for delivery between 2028 and 2030.

The company also secured new options for up to 50 more Boeing 787s and purchase rights for an additional 40 A321neo aircraft at the end of the decade.

In 2019, United averaged 104 seats per North American departure, among the lowest in the industry. By 2027, United expects that number to jump more than 40% to over 145.

The new aircraft will also reduce United's per-seat carbon emissions compared to the older models they replace, in line with the airline's expectation to be net zero by 2050.

"We're building a bright future at United and this order takes our already successful United Next plan into the next decade and beyond," said United CEO Scott Kirby.

United expects to take delivery of about 800 new narrowbody and widebody aircraft between 2023 and the end of 2032.

United expects that 75% of its fleet will be new-generation by 2030.

Price Action: UAL shares closed lower by 2.62% at $40.53 on Tuesday.