Washington:  American Airlines, which operates a direct flight between Chicago and New Delhi, announced the largest aircraft order, numbering 460 planes, in aviation history.

 Under the deal announced, American Airlines will acquire a total of 200 aircraft from the Boeing 737 family, with options for another 100 aircraft.

It will also acquire a total of 260 Airbus aircraft from the A320 family and will have 365 options and purchase rights for additional aircraft.

As part of these agreements, starting in 2017, American will become the first US airline to begin taking delivery of "next generation" narrow body aircraft that will further accelerate fuel efficiency gains.

These new deliveries are expected to pave the way for American to have the youngest and most fuel-efficient fleet among its US airline peers in approximately five years, the airlines said in a statement.

"With a total of 465 options and purchase rights for additional aircraft from both manufacturers through 2025, these agreements give American the flexibility for replacement as well as growth opportunities under the right economic and financial conditions, with the ability to acquire up to 925 aircraft in a total over 12 years," it said.

American will take delivery of 130 current-generation Airbus aircraft beginning in 2013.

Beginning in 2017, American will begin taking delivery of 130 aircraft from the A320neo (New Engine Option) family featuring next-generation engine technology.

The new aircraft are approximately 15 per cent more fuel efficient than today's models. American will be the first network airline in the US to deploy this new technology aircraft, said the airlines.