Bombardier has officially launched a high-density 160-seat variant of its in-development CSeries CS300.
The airframer says the higher-capacity aircraft requires the addition of a second pair of over-wing exit doors and will be available as both a line-fit and retrofit option.
Latvia's Air Baltic has become the first customer for the "extra capacity" jet, although it has opted to configure its aircraft with 148 seats.
It was not immediately clear if the 148-seat layout would be utilised on all 10 CS300s ordered by Air Baltic.
The CS300 is designed to seat 135 passengers in a standard two-class configuration and can seat up to 145 passengers with the standard exit-door layout.
The 160-seat version has been under evaluation by several major low-cost airlines including Vueling and EasyJet and was previously rejected by AirAsia.
The launch was announced as Bombardier prepared to publicly display the first CS100 flight test aircraft inside the final assembly hangar in Mirabel, Canada.
The CS100 is on-track for first flight by late June, with first delivery in 2014.