DALLAS (AP) -- Southwest Airlines Co. said Thursday that traffic fell slightly in January but a key revenue figure rose, an indication of higher fares.
Passengers on Southwest and its AirTran subsidiary flew 7.25 billion miles last month, down 1.7 percent from 7.38 billion in January 2012. The traffic figure could have been worse — boardings fell by nearly 4 percent, but the average trip was 2.2 percent longer, which improves the traffic number.
Despite less traffic last month, passenger revenue per available seat mile rose 2 percent from a year ago. For airlines, that's a closely watched statistic that measures revenue for every unit of production.
The statistic rose faster in early 2012 after a series of fare increases, but the pace of price hikes has slowed as Southwest and other airlines have grown wary of raising fares too fast in a tepid economy.
Southwest doesn't disclose average fares each month, but it recently reported that the average ticket in the fourth quarter was $148.02 each way, up 5.4 percent in a year.
Southwest and AirTran increased their combined passenger-carrying capacity by 0.5 percent in January, and the combination of more seats but fewer passengers led to less-crowded flights. The average flight was 72.7 percent full compared with 74.3 percent a year earlier.
Dallas-based Southwest is the nation's fourth-biggest airline by traffic.
Shares rose 3 cents to $11.50 in afternoon trading.