http://news.bbc.co.uk/1/hi/business/2852095.stm
United Airlines has failed to reach a deal with its employees' unions, making it increasingly likely that the group will miss a key deadline in its bankruptcy filing.
Credit rating group Standard & Poor's said war fears and higher fuel prices could hurt the airline to the point where it would not be able to meet its second set of bankruptcy covenants.
If that happened, its lenders could ask for an immediate re-payment of the $700m they are owed - forcing the airline to shut down altogether.