The parent company of United and Continental airlines says it lost $138 million in the fourth quarter because of the costs of integrating the two airlines.
Without special charges, United Continental Holdings Inc. says it would have earned $109 million, or 30 cents per share.
Analysts surveyed by FactSet had been expecting a profit of 13 cents per share.
Revenue rose more than 5 percent, to $8.93 billion, the same as analysts expected.
The company spent $170 million integrating the two airlines.
A year ago it lost $325 million because of integration costs. The companies closed the merger on Oct. 1, 2010.
Revenue for each seat flown one mile (1.6 kilometers) rose 8.2 percent as the company raised fares.