United will have new cabins on smaller planes with premium seats, including those that convert into a bed, to win more sales from high-spending travelers.

First class is shrinking across the airline industry as business class evolves, airlines cut costs, and passenger expectations reshape luxury flying.

Premium customers may be driving travel spending these days, but United’s David Kinzelman said airlines can’t forget about economy travelers. U.S. airlines have been going all-in on premium travel this year, adding more perks for top-tier flyers ...