The Associated Press

CHICAGO - United Airlines is upgrading to "restaurant-quality" meals on some of its flights this week. But just like in restaurants, most passengers will have to pay for them.

The nation's No. 2 airline, looking to raise revenue as it overhauls its money-losing operations in bankruptcy, began a six-day experiment Monday selling meals on its daily flights between Denver and Seattle.

Reflecting difficult times in the airline industry, United is the latest and biggest carrier to test the concept of charging for in-flight meals. America West, Northwest and US Airways conducted trials in select markets earlier this year.

United, which filed for Chapter 11 bankruptcy protection in December, scaled back its food service in January, eliminating meals on domestic flights lasting less than 3 1/2 hours. It is now considering restoring them in some markets, but this time they won't be free for economy-class passengers who want them.

Breakfast will cost $7 and lunch and dinner will be $10, while passengers in first class and business class will get the same selections for free.

"It's a convenience for our passengers and a possible new source of revenue for United," said Bill Dove, director of worldwide catering.

United is teaming with Gate Gourmet to offer what it characterized as restaurant-quality meals from Eli's Cheesecake Co. Passengers will have their choice of two options for breakfast and lunch/dinner, with different selections on the return leg.

For breakfast, they can opt for continental - cinnamon crumb cake, hazelnut biscotti, fresh fruit and berries - or brunch, which consists of a croissant sandwich with smoked turkey, Swiss cheese, hard-boiled egg slices and lettuce plus a raspberry strudel pastry bar and fresh fruit and berries.

One of the lunch/dinner offerings is a grilled turkey sandwich with a bowl of fresh fruit and a chocolate chunk cookie. United spokeswoman Chris Nardella didn't immediately have information on the other choices.

The selections didn't entice analysts, who are skeptical the concept will take hold in the industry despite all the recent tinkering.

"Airline food has been so bad - and getting scarcer - that people have been buying airport food to bring on board," said Scott Hamilton, an independent airline analyst based in the Seattle area.