United Airlines (UAL) - Get Report said Thursday that it agreed to buy 15 of Boom Supersonic's Overture airliners and took an option for 35 additional aircraft, once they satisfy the carrier's safety, operating and sustainability requirements.
The carrier declined to disclose financial terms of the accord.
United Air said the Overture is expected to be the first large commercial aircraft to be net-zero carbon and optimized to run on 100% sustainable aviation fuel.
The Overture can fly at mach 1.7, twice the speed of today's current airliners and will be able to connect more than 500 destinations in nearly half the current time, United said.
The airliner is scheduled to roll out in 2025, begin flying the following year, and carry passengers by 2029.
United said that potential routes include Newark to London in 3 1/2 hours, Newark to Frankfurt in four hours and San Francisco to Tokyo in six hours.
Founded in 2014, Boom Supersonic is headquartered in Denver and has about 150 employees.
The company, which is focused on sustainable supersonic flight, has raised $270 million from venture capital firms and other investors, according to The New York Times.
The last supersonic commercial flight was in 2003 when a British Airways Concorde completed its last trip between New York and London.
Late last month, United said ticket yields for the current quarter were returning to 2019 levels, but overall capacity was still expected to be down nearly 50% from pre-pandemic tallies.
The airline also offered vaccinated members of its MileagePlus loyalty program a chance to win free flights for a year's worth of travel.
Also in May, United said it would more add than 400 daily flights to its July schedule and increase services to reopened European destinations amid surging summer travel bookings.
Shares of the Chicago company at last check were down 0.9% at $59.73. The stock is up nearly 40% year-to-date.