United Airlines is in the process of resuming normal operations at several airports around the country after resolving its network outage Tuesday.
The airline was experiencing computer problems that affected operations at its airports and on its Web site, which was completely down for a couple of hours during the afternoon.
The network outage prevented passengers from printing out boarding passes for their flights and cause several delays and flight cancellations.
Even though the technology problems appeared to be solved, passengers were still reporting long lines at airports.
United flights to its hubs in Newark, N.J., Houston and San Francisco were being held at their origin, but begain moving at 4:30 p.m.
The airline is offering customers on affected flights the opportunity to cancel or rebook their itineraries without penalty.
United Continental Holdings Inc. has been struggling with computer issues ever since it combined some of its major computer systems in March.
Passengers are lighting up social media with complaints about the outages, with some saying boarding passes are being hand-written by United personnel.