By Doug Cameron Of DOW JONES NEWSWIRES Southwest Airlines Co. (LUV) on Sunday announced a modest increase in flying next summer alongside more international routes to be flown by its newly acquired AirTran unit. The largest carrier of domestic U.S. passengers plans to boost the number of weekday flights it operates by 1.1% between June 3 and Aug. 10 from a year earlier by tweaking its schedule. Southwest's summer schedule is closely watched by the industry because of its scale and price leadership in many markets. The airline didn't specify how much extra capacity it would add in the summer, and while Southwest plans to keep its fleet number flat next year, it is taking delivery of larger Boeing Co. (BA) 737-800 aircraft for the first time to replace its existing fleet of 737-700s and 737-300s. Southwest plans to end the year with 698 aircraft, with 33 new planes due to arrive in 2012, balanced by an equal number of retirements. The airline said in a release Sunday that 40 markets would see increased frequencies next summer while 21 would be trimmed, for a net increase of 36 departures daily. Southwest doesn't operate internationally, but its AirTran unit will add services to Puerto Rico and Mexico next year, as well as more transcontinental flights. Mexico is one of the largest markers where the U.S. lacks an open-skies treaty that allows unlimited flying between countries. However, Mexico has been relaxed about increased capacity since the collapse last year of Mexicana Airlines. -By Doug Cameron, Dow Jones Newswires; 312-750-4135 doug.cameron@dowjones.com
