American Airlines parent AMR posted an operating income of $55 million in May, but recorded a net loss of $132 million during the month due to bankruptcy related charges.
The Oneworld carrier reported revenues of $2.17 billion and expenses of $2.11 billion in May, according to a stock exchange filing.
Reorganisation-related charges during the month amounted to $134 million, the airline states.
AMR filed for bankruptcy protection in November 2011.