AMR, parent company of American Airlines, which filed for bankruptcy in November 2011, is reporting that it lost $1.1 billion in the fourth quarter. That compares with a $97 million loss a year earlier. For the full year, American said it lost $2 billion, compared to a loss of $471 million in 2010.

During the fourth quarter, American said it wrote down the value of planes and paid more for jet fuel. Those write-downs totaled $886 million, including $768 million due to write-downs on aircraft and $43 million from changing the way the airline recognizes revenue in its frequent-flyer program. On the other hand, American said fourth quarter revenues rose 7.4 percent to $6 billion.

American’s losses come in stark contrast to the profits reported by other legacy carriers, which are benefitting from economies of scale of mergers and of reorganizing under bankruptcy in earlier years. American had been the last of the legacy carriers to avoid bankruptcy. Delta, which absorbed Northwest Airlines, reported a $379 million fourth quarter profit and $1.2 billion annual profit. United reported a fourth quarter loss, but it attributed that to the costs of its merger with Continental Airlines.

American's mainline passenger revenue per available seat mile (unit revenue) increased by 8.9 percent in fourth quarter 2011 compared to fourth quarter 2010. Mainline capacity, or total available seat miles, in fourth quarter 2011 decreased by 1.9 percent compared to the same period in 2010. Taking into account the impact of fuel hedging, AMR paid approximately $3.01 per gallon for jet fuel in the fourth quarter of 2011 versus approximately $2.42 per gallon in fourth quarter 2010, a 24.5 percent increase. As a result, AMR paid $394 million more for fuel in fourth quarter 2011 than it would have paid at prevailing prices from the prior-year period.