Passengers paid 3 percent more per mile to fly compared to a year earlier. They paid more in add-on fees, too. United said so-called ancillary revenue, which covers items such as baggage fees, rose 15 percent in the quarter to nearly $21 per passenger.
Fuel expenses fell 4 percent to $2.97 billion for the quarter.
United said in November that it intends to cut $2 billion in annual costs. The company is still working to integrate Continental after their 2010 merger. Although all the paint on the planes and the signs at the ticket counters read "United," the company still has to schedule flight crews and planes separately for the two airlines, reducing the savings from the merger.
"Our goals for 2014 are to provide even more reliable operations, great customer service and materially better financial performance," chairman and CEO Jeff Smisek said in a written statement.
United said it expects a key measure of revenue to be flat to up 2 percent in the current quarter. Its main competitor, Delta Air Lines, on Tuesday predicted growth of up to 4 percent. Analysts expect Delta to report a profit in the first quarter of 27 cents per shares, excluding items, but are forecasting a loss for United of 29 cents per share.
United's guidance means its first-quarter loss would, at best, meet expectations, and at worst be as large as last year's adjusted loss of 98 cents per share, JPMorgan analyst Jamie Baker wrote.
"2014 appears off to a somewhat inauspicious start for UAL," he wrote.
For all of 2013, United earned $571 million, after losing $723 million in 2012. Revenue rose 3 percent to $38.28 billion.
Shares of the Chicago-based company fell $1.54, or 3.1 percent, to $47.64. They set a new 52-week high on Wednesday at $49.20.