Washington  - American Airlines parent AMR Corp and Delta Air Lines Inc Wednesday posted combined losses of 2.49 billion dollars, but the shares of both airlines rose more than 20 per cent as they planned to reduce flights and operating costs.

AMR Corp posted a net loss of 1.45 billion dollars, while Delta reported a loss of 1.04 billion dollars.

Delta and AMR, the world's biggest carrier, are the first of the eight major US airlines to report second-quarter results. US airlines plan to ground more than 460 planes and reduce domestic seats by 10 per cent or more to cope with a 52 per cent jump in the price of jet fuel this year, Bloomberg news agency reported.

AMR's losses were a result of employee severance packages and its decisions to ground several planes. Some of Delta's losses were due to charges for employee buyouts and the closure of airport frequent- flier lounges.

AMR will also bring forward plans to retire 34 Airbus aircraft to next year from 2012, and will step up seating capacity reductions by an unspecified amount. (dpa)