Oct 5 (Reuters) - Southwest Airlines Co said on Friday traffic fell 2.1 percent in September, as fewer passengers boarded its planes.
The Dallas-based discount carrier said traffic, measured by revenue passenger miles, fell to 7.76 billion in the month from 7.93 billion a year earlier. Capacity, as measured by available seat miles, was down 1 percent.
Passenger revenue per available seat mile, an important measure called unit revenue, is estimated to have fallen 2 percent to 3 percent in September from the year before. In the third quarter, unit revenue likely increased about 1 percent, Southwest added.
For the third quarter, traffic was down 0.6 percent as capacity shrank 0.7 percent.
Load factor, or the percentage of plane seats filled, edged down to 77.0 percent in September from 77.8 percent a year earlier.