WestJet has again deferred plans to reconfigure its Boeing 737 fleet with four rows of premium economy seating because it has yet to be granted regulatory approval from Transport Canada.

The Canadian low-cost carrier in August announced a plan to modify the seating of Boeing 737-600s, 737-700s and 737-800s, and expected the project to be completed by the end of the year. During the carrier’s third-quarter conference call in November, however, President and CEO Gregg Saretsky said regulatory holdups would delay WestJet’s plans to complete the work until the first quarter of 2013.

Now, a spokesman tells Aviation Week that the work will be completed “sometime in the first half of 2013.”

The spokesman attributes the delays to bureaucratic processes rather than possible objections to the reconfiguration. “We’re not anticipating that there are any issues with it,” he says. “When you’re looking at a whole fleet of 100 planes, it takes some time to go through each one of them.”

WestJet already has FAA approvals to proceed with the reconfiguration, he notes.

Transport Canada was not available for comment.

The carrier’s new regional, WestJet Encore, will not include premium economy seating on its fleet of Bombardier Q400s because the stage length will only average one to two hours, the spokesman adds. Encore is scheduled to launch in the second half of 2013.