Boeing has decided to produce an expanded version of its 787 Dreamliner aircraft in response to airline demand.
The first Boeing 787 is expected to be delivered in 2008
The "stretch" version of the 250-seat plane will seat 300 passengers and will begin flying in 2012.
Boeing said Emirates and about a dozen other airlines had been asking about such a plane.
It has staked much of its future on the success of the 787, and has been competing fiercely for orders with European rival Airbus' A350 aircraft.
Boeing took 235 orders for the Dreamliner in 2005 during a bumper year for the industry.
It expects to begin production of the 787 in 2007 and deliver the first of the aircraft the following year.
The company says its long-range 787 aircraft, which is designed to seat up to 250 passengers, will be 20% more fuel-efficient than similar mid-sized planes.