WestJet will reconfigure its entire fleet with premium economy seating by the end of the year while planning to take delivery of its first Bombardier Q400 turboprops in 2013 for new regional service.

The upgrade will affect the first four rows of WestJet’s Boeing 737s, increasing seat pitch to 36 in., President and CEO Gregg Saretsky says in a second quarter earnings conference call.

There are three seats in each row and no plans to change that number, a WestJet spokeswoman tells Aviation Week.

Current pitch varies with the type of 737, she says. The median average for the -600 and -700 series aircraft is 32 in., while the pitch for the -800 series is 34 in. “With the reconfiguration, you’ll see a slight decrease, but to nothing short of 31 in., the industry standard,” she says.

WestJet will add eight seats to its 17 737-800s but will not increase seat totals on the remaining 82 737s. Its 737-800s are configured with 166 economy seats.

The Canadian low-cost carrier will begin the reconfiguration this month and intends to finish by December. Upon completion of the upgrade, WestJet will introduce additional amenities, such as priority boarding, for the premium economy seats, Saretsky says.

At the same time, WestJet finalized a purchase agreement with Bombardier for 20 firm-order Q400s and options for 25 more.

The carrier intends to use the aircraft for regional service it plans to launch in the second half of 2013 on domestic and transborder routes, flights to new destinations, new routes between existing destinations and service on some short-haul routes that would benefit from increased frequency.

Seven of the 20 firm orders are scheduled for delivery in 2013, WestJet says. Seven more will follow in 2014, four in 2015 and two in 2016. The delivery range for the 25 options, if WestJet exercises them, would fall between 2014 and 2018.

WestJet will load its Q400 market schedule into global distribution systems in January, Saretsky says.