Budget airline Norwegian Air Shuttle is returning one of its brand new Dreamliners to Boeing , demanding repairs after the jet has suffered repeated breakdowns, it said on Saturday.

Norwegian Air Shuttle will instead lease an Airbus A340 from HiFly to keep its long-haul business going and will not take back the Boeing 787 Dreamliner until it is more reliable, a spokesman said.

"The aircraft's reliability is simply not acceptable, our passengers cannot live with this kind of performance," spokesman Lasse Sandaker-Nielsen told Reuters.

"We are returning the aircraft to Boeing to improve its reliability."

A Boeing spokeswoman could not immediately be reached for comment.

The Dreamliner was expected to be a game-changer for the aviation industry, but there have been delays getting it into service and setbacks including the grounding of all the planes due to battery problems.

Norwegian launched long-haul operations this year and hoped to capitalize on Dreamliner's lower operating cost as the jet's lighter-weight engines promised a 20 percent savings on fuel.

But its first two Dreamliners, part of a planned fleet of eight, broke down over half a dozen times in September, forcing it to lease back-up planes on short notice or cancel flights.

Norwegian summoned Boeing's management this week and the aircraft manufacturer promised to locate spare parts centers at all of the airline's long-haul destinations and send a team of engineers to the Nordics to monitor the planes.

The aircraft that will be returned is still stuck in Bangkok after a hydraulic pump failure this week and will be flown back to Stockholm where Boeing will carry out the work.

(Reporting by Balazs Koranyi; Editing by Hugh Lawson)