US aerospace giant Boeing has said orders for its 787 Dreamliner passenger jet have topped the 500 mark, more than a year ahead of the plane's launch.
Topping 500 Dreamliner orders is a "milestone", Boeing says
Fresh orders from a number of customers including Japanese airline JAL took the total Dreamliner order book so far to 514, Boeing said.
The plane, which has become one of the fastest-selling airliners, is set for its maiden test flight in August.
The jet boasts greater fuel efficiency as one of its key selling points.
Boeing said the Dreamliner had now attracted 43 customers since becoming available for orders in April 2004.
"This is an unprecedented achievement for Boeing and yet another wonderful milestone for the 787 programme," said Scott Carson, president and chief executive of Boeing Commercial Airplanes.
The firm has been investing heavily in development of the medium-sized jet, which it says will use 20% less fuel than other similar sized planes.
Boeing has also been working to avoid technical problems at the full production stage, highlighted by problems experienced at European rival Airbus with its giant A380 super-jumbo.
"Surpassing the 500 order mark this early in the programme - more than a year before the first airplane is delivered - shows that Boeing made the right choice in our point-to-point business strategy," said Mike Bair, the Dreamliner project's vice president and general manager.