DALLAS (AP) -- America's biggest airlines are reporting gains in passenger traffic and a key revenue figure just as travelers gear up for the busy summer-vacation season.
Monday's reports from American, Southwest and United indicate that U.S. airlines are continuing to prosper from solid travel demand and stable, although elevated, fuel prices. And that is boosting the stock of the companies.
American Airlines Group Inc., which owns American and US Airways, said that traffic rose 2.1 percent in May as passengers flew 19.2 billion miles. Domestic travel gained 1.7 percent and Latin American travel jumped 6 percent from May 2013, helping offset weakness in American's relatively small business of flying to Asia.
The company said that based on April and May results and a forecast for June, it expects that revenue for every seat flown one mile will rise by between 5 percent and 7 percent in the second quarter, compared with the same quarter last year. That is a closely watched statistic in the airline business, and it can rise when airlines sell seats at higher average prices.
Southwest Airlines Co. said that the same revenue figure rose 8 percent to 9 percent in May, compared with May 2013. Last week, Delta Air Lines Inc. reported a 7 percent gain for May.
Traffic on Southwest inched higher by 0.6 percent from a year ago, as passengers flew 9.4 billion miles last month.
United Airlines parent United Continental Holdings Inc. said that traffic rose 1.2 percent over May 2013. It did not give a revenue-ratio figure.
Average fares have been rising in recent years as mergers have left fewer major competitors. The remaining airlines have limited the supply of seats, helping to keep fares higher. In May, American and US Airways increased passenger-carrying capacity by a modest 2.4 percent while Southwest and its AirTran subsidiary cut capacity by 1.5 percent.
The average flight on American and US Airways was 84 percent full, down from 84.3 percent a year earlier. The average flight on Southwest and AirTran was 83.7 percent full, up from 81.9 percent a year earlier.
Shares of American Airlines fell 29 cents to close at $43.59 after hitting a record $44.43 earlier in the session. Southwest shares dropped 14 cents to $27.45 but reached a 52-week high of $27.70 earlier in the day. United Continental lost $1.67, or 3.5 percent, to close at $46.38.