FedEx Express said it will spend $2.6 billion over eight years to buy and refit nearly 90 medium-haul 757s, and use them to replace the older and smaller 727s that are now a staple of its domestic fleet.

The 757s can carry about 20 percent more payload but are more fuel efficient with a 25 percent lower per-pound operating cost, and are useful in domestic or regional service. FedEx said if it finds enough suitable aircraft to buy it will fold them into the fleet from 2008 to 2016.

The 757, though still a narrow-body plane, is wider than the 727 it would replace. FedEx said the fleet replacement plan would also bring it a quieter fleet with lower greenhouse gas emissions.

Among the airlines using 757 freighters are UPS - the main FedEx rival in the United States - and DHL in Europe.

John D. Boyd