UPDATE 2-Airbus's newest aircraft, A350, takes off on maiden flight
* Carbon-fibre jet "behaving well," chief pilot says
* Joins Boeing 787 in new generation of carbon-fibre jets
* Competition expected to dominate Paris Airshow
TOULOUSE, France, June 14 (Reuters) - Europe's newest jetliner, the Airbus A350, successfully began its maiden flight on Friday, stepping up a battle with arch-rival Boeing for sales of a new generation of sleek, lightweight passenger planes.
Watched by over 10,000 employees and spectators, the aircraft's curled wingtips sliced into clouds above the Airbus factory in southwestern France and headed over the Pyrenees, with a crew of six wearing orange jumpsuits and parachutes.
The flight, with two former fighter pilots at the controls, was expected to last four hours and caps eight years of development estimated to have cost $15 billion.
"The airplane is behaving extremely well," said British chief test pilot Peter Chandler, speaking by radio link from an altitude of 13,000 feet.
Co-pilot Guy Magrin, a former French air force pilot, took the controls for the take-off at 10:01 local time (0801 GMT), giving the plane air under its wings for the first time in front of a podium of airline chiefs who have ordered 613 aircraft.
"It is a great day for Airbus. A maiden flight doesn't happen that often. It is not like the auto industry where you launch a new model every two years or even less," said Tom Enders, the head of Airbus parent EADS.
The long-awaited sortie is a milestone for Airbus as it battles against Boeing's 787 Dreamliner for sales of a new generation of lightweight carbon-composite jets designed to save fuel and open up new long-distance routes.
Boeing has so far outsold Airbus using the revolutionary technology for aircraft woven from tough but lightweight carbon-plastic materials, with Dreamliner sales standing at 833 aircraft for 57 customers.
Airbus hopes to catch up with the Dreamliner and also mount a challenge to the U.S. manufacturer's larger, metallic 777 using a later version of the A350.
SETTING NEW STANDARDS
Airbus's ebullient New York-born sales chief, John Leahy, lost no time in talking up the plane's benefits moments after its Rolls-Royce engines opened up to full power.
"Did you hear how quiet it was? We are going to set new standards ... People round airports won't even know we are taking off," Leahy said.
Didier Evrard, one of Europe's top missile developers selected to run the A350 programme because of its complexity, smiled broadly but refused to relax.
"I will be still nervous until it comes back. I'm an engineer so I have to be connected to the ground and make sure everything is fine," he said.
Competition for wide-bodied jets is expected to dominate next week's Paris Airshow, where the A350 could steal attention with a brief roar over the aviation industry's largest showcase.
Airbus is finalizing orders from Singapore Airlines, Kuwait Airways and Air France and may add a new customer at the June 17-23 show, analysts say.
Evrard said Airbus would soon add a customer in the United States, where industry sources say United Airlines is negotiating to upgrade and expand an existing order to 35 jets.
Airbus initially dismissed the threat posed by the new generation if mid-sized airplanes as it focused on building the world's largest airliner, the A380 superjumbo.
But faced with burgeoning Dreamliner sales, it changed tack and overhauled the design of the A350 by adopting similar composites technology in 2006.
To boost sales, Boeing is expected to confirm plans to build a larger version of its Dreamliner. It is also overhauling its 777 with new engines and wings.