STORY: U.S. airlines are enjoying a summer travel boom.
More than 3 million people got on a plane there in a single day on July 7.
But that isn't translating into bumper profits.
On Wednesday, United Airlines disappointed markets with a lower-than-expected forecast for the current quarter.
It now expects adjusted profit of at best $3.25 per share - nearly 20 cents below analyst forecasts.
That comes after airlines increased capacity by even more than demand - forcing them to offer discount tickets in a bid to fill planes.
Official statistics show U.S. airfares fell by an average of 5.6% over the June quarter.
The industry also faces higher costs for labor and other operating expenses.
Now United says it will reduce its domestic capacity in the fourth quarter in an effort to revive ticket prices.
Its wary outlook follows similar comments from rival Delta last week.
There too, profit forecasts came in shy of Wall Street expectations.
Analysts say a long-awaited rationalization is now taking place in the industry.
That could restore profits - and spell an end to cheap air travel.
