NEW YORK » The gap between first class and coach has never been so wide.

Carriers on international flights are offering private suites for first-class passengers, three-star meals and personal service once found only on corporate jets. They provide massages before takeoff, whisk passengers through special customs lanes and drive them in a private limousine right to the plane. Some have bars. One airline has installed showers onboard.

The amenities in the back of the cabin? Sparse.

So as domestic travelers take to the skies for the holiday season, most will be sitting in cramped cabins, their food is likely to be bland and they will have paid for it, along with any fees for slightly more legroom or checked bags. But even as they have cut back on domestic service, including first-class accommodations, the airlines have been engaged in a global battle for top executives and the superwealthy on their international routes. Though only a privileged few can afford to pay $15,000 to fly first class from New York to Singapore or Sydney, the airlines are betting that the image of luxury they project for the front helps attract passengers to the rest of the plane. That includes a growing business-class section with offerings once solely the preserve of first class.

Though first class now represents less than 5 percent of all seats flown on long-haul routes, and business class accounts for 15 percent, those seats combined to generate 40 percent to 50 percent of airlines’ revenue, according to Peter Morris, the chief economist at Ascend, an aviation consulting firm.

As a general rule, business class is five to 10 times the price of an economy ticket, while first class is usually twice the price of business.

"First class," said Brett Snyder, president of Cranky Concierge, an air travel assistance website, "is status."

Until the 1980s, first class was roomier than coach, but not all that fancy. The seats in the front offered more legroom but did not recline more than 40 percent. The food was better in first class too, though even the meals in coach were better than they are now. With globalization, particularly the rise of Asia, passengers began demanding more from first class, especially with new planes that could fly much longer routes without stopping.

In recent years, the airlines most aggressive in adding luxury touches to first class have come from Asia and the Middle East, among them Cathay Pacific Airways and Singapore Airlines. Emirates, based in Dubai, came up with personal suites for first-class passengers in 2003 and in 2008 installed two showers on its Airbus A380 planes for them.

European airlines quickly recognized the threat. Air France, for instance, now has a dedicated first-class lounge in Paris with a spa and a restaurant catered by the chef Alain Ducasse. Immigration officers come directly into the lounge to check passports, and passengers are driven to the airplane in a limousine only seconds before the doors shut.

But U.S. carriers were slower to react, largely because they lacked the funds to upgrade their cabins until recently. Now, they have little choice. International rivals are starting to encroach deeper into their domestic markets, beyond New York and Los Angeles. Emirates, for instance, announced it would begin service from Dubai to Dallas and Seattle early next year.

"If you don’t refurbish your cabins, then all you are left with is the low-yielding traffic," Morris said. "It’s just not an option."

The first class has also served as a laboratory for in-flight amenities that eventually trickled down to the rest of the plane. Individual screens are now found in the seatbacks in coach. Lie-flat seats have moved down to business class.

In fact, business class has become so comfortable that, in many cases, it can rival first class itself. "People demand more from the business class than they used to," Snyder said.

That is why some airlines have concluded that the market for first-class passengers is just too slim to justify the investments, especially since passengers sitting in the front seats are often upgraded from business class or got their tickets using airline miles.

"A plane is only so big," said Jim Compton, the chief revenue officer at United Continental Holdings. "And the reality is that demand for the product in all markets is not necessarily there."

Following its merger with Continental last year, United Airlines decided to keep its first-class cabin only on some international routes that used to be served by United but not on those flown by Continental. It is also installing new flat-bed seats across its fleet in business class.

Delta Air Lines and Qatar Airways, by contrast, do not have a first class, just business and coach. Others have reduced the number of seats in first class. Air France now flies planes with first-class seats to only 28 international cities, out of a network of over 250 destinations.

Nothing compares with the experience of flying first class, said Geoffrey Fischer, a 33-year-old social media consultant based in Seattle. Even after his 15-hour flight on Cathay Pacific landed in Hong Kong, he did not want to get off the plane, he said.

Throughout the trip, which he also wrote about on the Cranky Flier blog, he was plied with Champagne and wine. He was served caviar as an appetizer on fine bone china and a linen tablecloth. His seat turned into a full-size bed. He was handed designer pajamas to wear while an attentive flight attendant made up his bed, complete with a pillow, duvet and sheets.

"I’ve never experienced such a private jet atmosphere," said Fischer, who snagged his seat thanks to frequent flier miles. "It was the best flight I’ve ever been on."

© 2011 The New York Times Company