United Airlines back 'up' system nationwide failure

"Our systems are up. We are in the process of resuming (operations)," the airline said in a post to the blogging site Twitter. It said it was working out a penalty waiver for those whose plans with the airline were affected.

Glitches that also affected the main website were fixed, the airline said, adding: "We again apologize for the disruption caused to our customers."

"At approximately 7:15 pm central time (0015 GMT Saturday), United Airlines experienced a computer outage interrupting the airline's flight departures, airport processing and reservations systems," the airline said in a statement released late Friday.

The problems left thousands of passengers across the country stranded, some on planes and others waiting in airports.

One airline traveller in Portland, quoted by the Denver Post, said the airline had announced to passengers they were "having system wide computer problems affecting everything from reservations to weather reports for pilots."

The Chicago-based airline did not say whether other airlines -- notably its partner Continental were affected by the outage.

United merged with Continental on October 1 last year to form the world's largest airline group, with a cumulative total of some 5,820 flights daily, though the two companies still operate separately.

Copyright AFP (Agence France-Presse), 2011