United Airlines says it will retire its Boeing B747 jumbo aircraft by the end of 2018.
This accelerated retirement schedule has been made possible by the carrier converting an existing order for B787 aircraft, which had been due to be delivered from 2020.
The amended order will now see four B777-300ERs and five B787-9s delivered from 2017.
In addition United has announced a new order for 25 B737-700 aircraft, adding to an existing order of 40 B737s, with deliveries starting from the end of 2017.
The US carrier says the new order will allow it to reduce its 50-seater regional fleet to under 100 aircraft by 2019.
Commenting on the retirement of the airline’s jumbos, Gerry Laderman, United's senior vice president of finance and acting chief financial officer said:
"Retiring the 747 fleet and replacing those aircraft with more customer-pleasing, current generation aircraft creates a more reliable and efficient fleet that provides a better overall experience for our customers traveling on long-haul flights."