United has struggled with technology glitches and other issues that have left it behind other airlines in key revenue ratios, but second-quarter revenue rose 3.3 percent to $10.33 billion, slightly higher than Wall Street forecasts, partly due to higher "ancillary revenue" from extra fees.
Southwest Airlines Co. reported a record second-quarter profit of $465 million and set records for full planes and passenger fare per mile. Revenue rose 8 percent.
CEO Gary Kelly said that bookings were strong in July, with passengers paying about 3 percent more per mile than in July 2013. The company expects to grow through international flying that it picked up with the 2011 acquisition of AirTran Airways and expansion in Dallas, where a federal law that limited its flights expires in October.
"Demand is very strong, and it is balanced very nicely with the supply of seats," Kelly said on a conference call with reporters. "We're going to manage our growth very carefully so that we don't upset that balance."
Kelly said his biggest worries about the demand-supply balance centered on the economy or events in the Middle East causing a spike in jet fuel prices.
JetBlue Airways Corp. said earnings jumped six-fold to $230 million. Revenue grew 12 percent.
Airline stocks have surged in the past two years but have also had down days recently due to concern about growth in capacity on lucrative international routes.
In afternoon trading, shares of American Airlines fell $1.03 to $42.30; United lost $1.18 to $44.82; Southwest slipped 36 cents to $28.51; Delta Air Lines Inc. fell $1.09 to $38.06; and JetBlue fell 20 cents to $11.08.