Southwest Airlines Co. says passenger revenue in June accelerated while traffic remained virtually flat.
Dallas-based Southwest said Monday that flew paying passengers 9.62 billion miles last month -- compared with 9.63 billion miles in June 2011. The airline's capacity, or number of available seats, fell 0.7 percent.
Passenger revenue per available seat mile, which measures the money collected from flying one passenger a single mile, rose about 6 percent.
Because the number of available seats fell while traffic remained steady, flights were packed tighter. Southwest's occupancy rate rose 0.5 percentage points to 84.4 percent.