UNITED UPS GAME IN AIRLINES RACE WITH MORE FANCY SEATS

United, Delta and American Airlines are engaged in an airlines arms race to grab the most affluent customers.

Now highly profitable after losing billions of dollars in the 2000s, they are plowing money into new planes, fancy seats with more legroom, airport lounges and other perks, many of which are aimed squarely at well-heeled travelers.

United raised the stakes when it announced Wednesday that it will retrofit more than 100 planes as part of a move to add 1,600 premium seats on nearly 250 jets.

The airline also plans to start using a new 50-seat jet with mostly premium seats on some routes popular with business travelers.

The decision is part of a larger industry trend to give more space and better service to high-paying passengers who account for a disproportionate share of airline revenue.

Andrew Nocella, United’s chief commercial officer, said executives decided that the airline has “a shortage of business-class seats into the premium markets, and this fixed that problem.”

“It helps our customers and it helps our bottom line,” he said.

Henry Harteveldt, an airline analyst at Atmosphere Research, said United’s announcement was a bold challenge to Delta Air Lines, the acknowledged front-runner among the nation’s top three carriers for its on-time performance and strong profit margins.

“This is big news. They are taking direct aim at Delta and its strength with premium travelers,” Harteveldt said.

Delta executives say they have increased premium seating from 9 percent to nearly 30 percent since 2011, and they’re selling more than 60 percent of those seats, up from 13 percent — not just giving them away in the form of upgrades.

American has added “premium economy” seats — often double the price of regular economy but less than business class — on many of its planes used for international flights.