By Helen Jung
The Associated Press

SEATTLE - Boeing Co. is shelving its proposed high-speed Sonic Cruiser passenger jet in favor of developing a more traditional but highly fuel-efficient airliner, the head of Boeing Commercial Airplanes said Friday.

Commercial airplanes chief executive Alan Mulally said that while airlines had shown interest in the high-tech cruiser, they felt the fuel-efficient plane was more important.

"The real key is going to be the efficiency in terms of fuel burn," Mr. Mulally said. "Everybody is behind us. ... The airlines' response has been very enthusiastic."

Although no orders have been received for either plane, Mr. Mulally said Boeing estimates the eventual market for the as-yet unnamed mid-sized jet could reach 2,000 to 3,000 jets over its lifetime. He said Boeing hopes to launch the plane in 2004.

The Sonic Cruiser project, announced in March 2001, was envisioned as a mid-sized jet carrying about 250 passengers that could travel near the speed of sound and shave two or three hours off international flights.

The concept was unveiled as Boeing shelved previous plans to develop a larger version of the 747 jumbo jet.

But even though it wouldn't have started flying before 2008, the timing proved bad as airlines struggled to stay in business amid the worst downturn in commercial aviation history.

With its huge triangular wing, twin vertical fins and small canards or forward wings, the plane was one of the most radical designs in the history of commercial aviation.

Boeing has not escaped the hit that airlines are taking. It has slashed production in half, cut 30,000 jobs and announced another 5,000 reductions for 2003.

It also has deferred deliveries for more than 500 jets - a year's worth of production - and is projecting a lean year in 2003 with 275-285 deliveries.

Boeing has for months said it was considering both the Sonic Cruiser and the more conventional jet. Both planes would carry between 200 and 250 passengers more than 8,500 miles.

The Sonic Cruiser, however, would travel 15 percent to 20 percent faster than today's commercial jets while the more traditional plane, which would look like a scaled-down 777, would be between 17 percent and 20 percent more fuel-efficient than a 767.

Boeing will continue to look at the Sonic Cruiser concept, he said, but will devote most of its development to the traditional jet.

Boeing has said it can incorporate some of the technologies developed for the Sonic Cruiser, such as lighter-weight materials, in the other plane.