AMR Corp.'s regional carrier, American Eagle, said Tuesday it would return 21 aircraft to its lessor and cut flights, likely resulting in layoffs at its Dallas/Fort Worth International Airport operations.

American Eagle, the sister carrier of American Airlines, will aim to use bankruptcy court to return 21 ATR turboprop airplanes to its lessor, including 15 active aircraft at DFW and another six that have been grounded, said Dan Garton, the airline's president and chief executive, in a letter to employees.

AMR filed for bankruptcy-court protection last month. After the filing, AMR said it has halted plans to spin off American Eagle.

American Eagle will cancel service between DFW and Augusta, Ga., but the 14 other markets served by the ATR turboprops from DFW will now be served by regional jets, Mr. Garton said.

American Eagle will also cancel routes between Chicago and Tri-Cities, Tenn.; Miami and Savannah, Ga.; and Miami and Fort Myers, Fla. The carrier will cut capacity elsewhere, Mr. Garton said.

The announcement comports with American Eagle's warning to Texas officials last week that it may furlough 119 pilots and 104 flight attendants based at DFW because of fleet reductions.

AMR will "undoubtedly" ground more planes and "most certainly" furlough more employees as the Fort Worth, Texas, airline slogs through Chapter 11, Tom Horton, AMR's chairman and chief executive, said in a letter to employees last week.