AMR said passenger traffic dropped 2.8 percent in September as the carrier struggled with operational delays and cancellations.
The parent company of American Airlines said its capacity declined 3.4 percent compared to September 2011. Its consolidated load factor increased 0.5 percentage points to 81.1 percent.
AMR said its unit revenues grew 4.0 percent compared to last September.
"Absent the impact of operational challenges due to flight cancellations and delays during the second half of September, unit revenue improvement would have been approximately 0.4 points higher," the company said.
AMR has blamed some of its operational problems on pilots filing last-minute maintenance requests, delaying hundreds of flights. The pilots union said it is not coordinating a work slow down at the bankrupt carrier.
At its mainline operations, passenger traffic declined 2.9 percent while capacity dropped 3.4 percent. At its regional operations which includes American Eagle, passenger traffic dropped 1.4 percent while capacity declined 2.7 percent.
Domestic passenger traffic was affected the most by the numerous flight delays and cancellations decreasing 7.1 percent with capacity down 5.5 percent.
International passenger traffic rose 3.2 percent on 0.5 percent less capacity, AMR said.