Delta will put lie-flat seats in its business class in 2008, joining other larger carriers that have recently introduced the service to attract well-heeled customers.

The "fully horizontal" seats convert into a 75-inch bed and are equipped with a fold-out monitor for on-demand entertainment.

The carrier initially will install them in two 777 planes it will get from Boeing in early 2008. By 2010, the Atlanta-based carrier plans to have them in its entire fleet of 777s and 767s that fly internationally.

The service won't be available on domestic flights.

With the airline industry in recovery after years of sluggish demand, carriers are more aggressively courting elite customers, who generate higher profit margins.

As airlines add more international routes, the race to offer sleeping chairs in business and first class is becoming more heated, says Paul Metselaar, CEO of Ovation Corporate Travel, which specializes in travel for lawyers and financiers.

"Our clients are increasingly making the decision on who they will fly based on seats and the distance between them," he says. "Now that we don't have Concorde, this is the next best seat."

British Airways kicked off the competition in 2000 when it introduced lie-flat seats in business class. It was followed by other foreign carriers. U.S. carriers, mired in losses in recent years, were slower to come around, although United, Northwest and American eventually adopted the trend.

The seats and their in-flight entertainment systems cost as much as $50,000 each. Even though Delta has yet to emerge from the bankruptcy-court protection it filed in 2005, it decided to install them because "we know we have to invest in our products to have a successful business," spokeswoman Betsy Talton says.

In 2003, Northwest Airlines, also in bankruptcy protection, became the first U.S. carrier to install flat seat-beds at a slight angle to the floor in its international business class. Northwest now offers the beds on 37 jets flying between the U.S. and both Europe and Asia.

American Airlines, the No. 1 carrier in the U.S., has been replacing its business-class seats on long-haul 767 planes with seat-beds that are slightly angled to the floor. It will complete the process in the first half of next year. American will then install seat-beds on its 777s.

United, which exited bankruptcy this year, has installed flat seat-beds in first class on most of its 747s and 777s flying international routes. In 2004, it installed seat-beds on jets between New York and both San Francisco and Los Angeles.

Rob Newman, a TV commercial producer who splits his time between Thailand and Malibu, Calif., says the seat angle makes a big difference in his sleep. "You do sleep better on a true lie-flat seat," he says.

His last journey included several flights with almost-flat seats. "You let the sleeping pill and glass of wine help compensate for a slightly worse sleep."