The No. 2 U.S. carrier, which is required to file a monthly operating report with the bankruptcy court, said its August operating loss was $12 million.
UAL has been operating under Chapter 11 (search) protection since December 2002.
The Elk Grove Village, Ill.-based airline said high fuel prices and weaker fares due to heavy competition continued to weigh in August. Fuel prices averaged $45 a barrel last month, compared with $32 a barrel a year earlier, the company said.
"The environment does not appear to be changing, so we must, if we are to be competitive," Chief Financial Officer Jake Brace said in a statement. "The situation underscores our need to quickly reduce our cost structure even further and move forward with our restructuring work and our efforts to attract suitable exit financing."
UAL ended August with a cash balance of about $2 billion, including $839 million in restricted cash. Its cash balance decreased about $77 million during the month.
The carrier also said it met the requirements of its debtor-in-possession financing for the month.