Southwest Airlines upped its second-quarter profit to $161 million from last year's $112 million.

This year's quarterly profit includes AirTran's contribution from May 2, when Southwest closed the acquisition of the Atlanta-based airline. On a combined basis for the second quarter, the average one-way fare increased 10 percent year over year to $142.68 and traffic grew nearly 9 percent. Southwest expects to grow full year 2011 capacity by no more than 5 percent, down a percentage point from previous plans. Meanwhile, next year's capacity will be "equal to or less than our 2011 combined available seat miles," according to CEO Gary Kelly.