MONTREAL – Air Canada briefly grounded its planes Thursday due to a problem with its computer system, delaying nearly half its flights.

A “technical issue” with the system the airline uses to communicate with aircraft and monitor their performance prompted a halt to operations, the Montreal-based company said.

“There have been some delays as a result, but the system is now returning to normal, and the precautionary ground stop has been lifted,” said spokesman Peter Fitzpatrick in a statement Thursday afternoon.

“The effects were limited.”

As of Thursday night, 241 Air Canada flights _ 46 per cent of its trips that day _ were delayed, according to tracking service FlightAware. That compares with about 35 per cent on Wednesday and 30 per cent on Tuesday.

Another 19 flights were also cancelled Thursday.

Air Canada said it advised Nav Canada and the U.S. Federal Aviation Administration of the temporary freeze, which lasted about an hour.

The FAA posted an advisory stating all Air Canada and Air Canada Rouge flights were put on hold “due to internal computer issues.”