American Airlines will announce an aircraft purchase on 20 July, ending a month of speculation since the Paris air show over the timing of the order, which could be for more than 250 single-aisle aircraft, industry sources confirm.
There are strong suggestions that parent company AMR is set to split the order between Boeing and Airbus, breaking Boeing's previous stronghold as the main narrowbody aircraft supplier to American.
The AMR board is expected to meet to ratify the deal, or deals, on Wednesday before it discloses its plans, which could include a partial replacement of its 200-strong MD-80 fleet. During the last couple of years American has been taking deliveries of Boeing 737-800s as MD-80 replacements, and the current delivery stream includes 15 deliveries in 2011, 28 in 2012 and 14 in 2013.
Previously, American has said it intends to retire at least 25 MD-80s this year.
As of 31 March, American also operated 124 757-200s with an average age of 16 years.