United Airlines announced it will buy 25 more Boeing 737 Max jets for delivery in 2023 in a sign of an expected post-pandemic travel industry recovery, according to a report by Agence France-Presse Tuesday.

It marks one of United's biggest orders for the troubled plane since it was grounded in March 2019. United is the second U.S. airline company to put the Boeing 737 Max back to service a few weeks ago. Airlines worldwide saw slumps in passenger traffic during pandemic lockdowns, though the U.S. market has managed to buffer international losses.

On top of the 25 B737 Max planes that are scheduled for delivery in 2023, United said it moved up the delivery of 40 other Max aircraft to 2022 and five others to 2023.

This puts United's firm commitments to a total of 188 Maxes, a filing with the Securities and Exchange Commission shows. The order is a boost for Boeing, which saw hundreds of MAX orders scrapped during an almost two-year grounding after two deadly crashes of the jet in Ethiopia and Indonesia that killed almost 350 passengers.

The U.S. Federal Aviation Administration (FAA) lifted its ban on the 737 Max in November, requiring the plane to undergo a series of software updates and pilots to go through additional training, among other safety measures.

"We have now placed ourselves in a position to not only survive the crisis, but thrive as an airline, elevate our product for customers and emerge as a stronger, better United Airlines," Chief Operating Officer Andrew Nocella said in remarks quoted by USA Today.

Passenger volumes are still below half compared to year-ago levels, based on government statistics.

That marks a major improvement from the worst days of the coronavirus pandemic, but airlines are still shedding cash.

United is pushing for additional federal stimulus to help keep jobs, Nocella said in a note to employees announcing the MAX orders.