Seattle: American Airlines, the world's largest airline agreed on Wednesday to buy 47 Boeing 737-800 jets for delivery starting from 2009.
The aircraft will begin replacing American's fleet of more than 300 operational MD-80s, which are on average 17 years-old and burn 25 per cent more fuel than the 737s already in its fleet.
Boeing recently said its 737 order book was full until early 2011, however, American's position as the world's largest airline is expected to give it priority in securing production slots.
The current order will be delivered over four years.
So far, the MD-80s are the workhorse of the American fleet, and account for almost a third of all its traffic.