Southwest, the world's most profitable carrier, has traded on humor since its first flight in 1971, projecting a personality that was not formal or corporate.

Mr. Maldutis and other analysts believe that American could emerge as a highly profitable carrier.

Southwest Airlines, the only consistently profitable carrier in recent years, has a customer-pleasing combination of low fares and staff enthusiasm.

But their frustration suggests a summer of potential labor problems for Southwest, the only profitable major carrier in the United States.

He can feel pride that he has groomed the consistently profitable carrier into a business attractive enough to lure at least two suitors.

At Southwest Airlines, the only consistently profitable major carrier, a seat-mile costs about 7.5 cents.

Eastern still faces large hurdles in its effort to emerge from bankruptcy protection as a profitable regional carrier.

Singapore Airlines, usually one of the world's most profitable carriers, reckons the outlook is 'grim'.

"What we need to see now is how they intend to turn that position around and become a profitable carrier," Mr. Tiberi said.

And it is jealously trying to copy some techniques that have made Southwest Airlines the only consistently profitable major carrier.