Last Updated Sep 17, 2015 1:59 PM EDT
DALLAS -- American Airlines says it has fixed the connectivity issue that stopped flights heading to and from Dallas, Chicago and Miami. The ground stop has been lifted on all three cities.
In a tweet Thursday afternoon, American Airlines said passengers would be on their way soon.
Airline spokesman Casey Norton said Thursday that the outage began around 11 a.m. CDT.
"We're working to resolve technical issues impacting several airports as quickly as possible," the airline said in a statement. "We will provide updates and more information as they become available. We apologize to our customers for the inconvenience."
The Federal Aviation Administration said American planes destined for Dallas-Fort Worth International Airport, O'Hare Airport in Chicago and Miami International Airport were being held on the ground.
O'Hare Airport had tweeted that "delays are anticipated" because of the problem.
American did not immediately say how many flights were affected.
The outage comes at an awkward time for American Airline Group Inc., the world's biggest airline. In less than a month, the company plans to complete combining the reservations systems of American and its US Airways subsidiary and retiring the US Airways brand.
Combining technology systems is a difficult feat that has tripped up other airlines, notably leading to several outages at United Airlines after it merged with Continental Airlines in 2010. United suffered two major outages this summer.
American has made meticulous plans to avoid a similar fate. Among other moves, it will reduce flights to lighten the load on its network while it combines the two reservations systems.
One passenger at O'Hare took to social media to report on the ground stop.