Canada's largest carrier had said earlier that an issue with its communicator system had resulted in flight delays across its system.
"Air Canada's operations are stabilizing and flights are departing," the airline said Thursday afternoon.
The system, used to communicate with aircraft and monitor performance, was also behind issues on May 25 that forced the airline to undertake a temporary ground stop.
Air Canada did not describe the specific issue but said Thursday's glitch was unrelated to the one last week.
"We have been in the process of upgrading this system using a third-party supplier's technology," the carrier said, without naming the supplier. "Air Canada will continue to work with the manufacturer to ensure stability in the system in the future."
Technical problems have resulted in delays globally for airlines. Southwest Airlines Co blamed a one-hour stoppage of its flights in April on a vendor-supplied computer network firewall.
Separately, Spirit Airlines on Thursday said it resolved an issue with a third party that affected usage of the U.S. carrier's website, mobile app and some internal applications.
"We're now working our way back to normal operations," Spirit said in an emailed statement.
(Reporting by Allison Lampert in Montreal and Ismail Shakil in Ottawa; Additional reporting by David Shepardson in Washington ; Editing by David Gregorio and Mark Porter)
By Allison Lampert and Ismail Shakil
