American Airlines returned to the red in February.The Fort Worth-based carrier's parent company, AMR Corp., said it lost $192 million last month, according to a bankruptcy filing Thursday.AMR, which has operated under bankruptcy protection since November 2011, announced plans last month to merge with US Airways, which the bankruptcy judge approved Wednesday. The merger is expected to close in the third quarter.Excluding $15 million in reorganization fees, the carrier posted a monthly operating loss of $177 million. During bankruptcy, AMR is required to file monthly financial reports with the court.The company said it spent $14 million on professional fees during the month and $1 million on financing negotiations.AMR said its mainline operations at American had passenger revenue of $1.4 billion. Its regional affiliates, including American Eagle, brought in $200 million. Total revenue for the month was $1.8 billion.The company ended the month with $584 million in cash and $3.4 billion in short-term investments, for a total of about $4 billion on hand. That does not include $850 million in restricted cash.The merger with US Airways still needs approvals from US Airways shareholders and government regulators. The Justice Department is reviewing the deal and could require the carriers to give up flight slots at Reagan National airport in Washington, D.C.Speaking at a U.S. Chamber of Commerce aviation conference Thursday, US Airways CEO Doug Parker, who will run the combined carrier, said he doesn't think the merged airline should cede any slots."It is an incredibly competitive market in the D.C. area," he said. "There is no reason for us to divest slots, legally or otherwise."The combination of American and US Airways will control only 25 percent of the aircraft seats in a market that includes Washington Dulles and Baltimore/Washington Thurgood Marshall airports, Parker said.U.S. regulators limit takeoff and landing slots at Reagan National, where US Airways says the postmerger American will have 67 percent of daily departures.Parker spoke after JetBlue Airways CEO Dave Barger said the merged airline should have to give up flights in Washington."It is not right for one airline to have two-thirds of the slots at one airport," Barger said in an interview. "We feel very strongly about this."Barger urged the U.S. government to order the merged carrier to surrender an unspecified number of slots that would be auctioned to other carriers. New York-based JetBlue wants to expand its operations in Washington, he said.Star-Telegram staff writer Andrea Ahles contributed to this report, which includes material from Bloomberg News.