A computer outage at United Airlines delayed thousands of travelers Thursday and embarrassed the airline at a time when it's trying to win back customers after glitches earlier this year.
The two-hour outage held up 250 of the 5,679 United flights scheduled for Thursday, the airline said.
It was at least the third major outage for the Chicago-based airline since June.
"There were no backups or long lines at United's ticket counters," said Laura Coale, spokeswoman at Denver International Airport. "The problem was resolved at around 9 a.m."
Major delays across the world, especially those early in the morning, can easily ripple throughout an airline's network. United runs about 5,500 flights a day worldwide.
During the system failure, some furious passengers vented their anger on social media sites.
"Does anyone have a RadioShack computer or abacus to help United get their system fixed?" tweeted Lewis Franck, a motorsports writer who was flying from Newark, N.J., to Miami Thursday to cover the last race of the NASCAR season.
United is offering a refund for customers delayed more than two hours due to the outage, or will waive the re-booking fee for passengers in all cities.