United Airlines briefly stops flights after system outage

United Airlines suffered a brief system outage early Friday and the Federal Aviation Administration issued a ground stop of less than an hour for all United flights.

The ground stop order was lifted before 8 a.m. at the airline's request, according to an advisory issued by the FAA.

"We experienced a system outage this morning, but everything is up and running and operations have resumed," the Chicago airline said just after 8 a.m. Eastern on Twitter.

It was unclear how many delays occurred, or if there were any related cancellations.