Brazilian low-cost carrier Gol plans to complete the addition of extra legroom Gol+ seats to its Boeing 737 fleet by the end of the year.

About 90% of the airline’s fleet is configured and the rest will be done by the end of the year, says Paulo Sergio Kakinoff, chief executive of Gol, during an investor event in New York on 8 September.

The retrofit includes 22 extra legroom seats with 34in of seat pitch up from 30in and 50% more recline than standard economy on its 737-800s. The addition standardises the configuration of the aircraft at 177 seats, compared to 178 and 183 seats previously.

Retrofitted 737-700s have 138 seats, which is down from 144 previously.

Gol+ is very popular and often sells out, says Kakinoff. The airline charges passengers to move up to the seats, though they are available for free to top tier frequent fliers.

The extra legroom seats are helping Gol boost revenues. Passenger revenue per available kilometre (PRASK) increased 29.8% to 18.35 Brazilian real cents in the second quarter.

The carrier anticipates a 10% increase in revenue per available seat kilometre (RASK) for the full year of 2014.

Gol introduced Gol+ on five aircraft operating the Rio de Janeiro Santos Dumont-Sao Paulo Congonhas shuttle flights in November 2013.

The airline operates 33 737-700s and 96 737-800s, the Ascend Fleets database shows.

Source: Cirium Dashboard