American Airlines' parent company says it lost $904 million in December _ more than in the first nine months of 2011 combined.
Revenue was $2 billion in December, American's first full month operating while under bankruptcy protection.
AMR Corp. also listed $4 billion in cash and short-term investments. That's down from $4.3 billion at the end of September.
AMR disclosed the numbers in a filing Tuesday with a federal bankruptcy court in New York.
Company executives were scheduled to meet with employees Wednesday in Fort Worth, Texas, to detail concessions that they want from unions under a reorganization plan. Unions expected the company to propose job cuts and either freeze or end American's pension plans.
AMR filed for bankruptcy protection on Nov. 29. It lost $884 million in the first nine months of 2011 and about $11 billion since 2001.
For December, the company said its operating loss was $728 million. That figure excludes some reorganization costs, including $102 million for aircraft-refinancing negotiations and $14 million in professional fees.
American's labor unions have raised concerns about the amount that the company is spending to hire lawyers and restructuring consultants.
In the bankruptcy court filing, AMR did not present data from December 2010 for comparison. Previously the company filed its earnings results with the Securities and Exchange Commission on a quarterly basis.