Mitsubishi Heavy Industries Ltd.'s new regional jet, Japan's first such aircraft, won fresh support from U.S. commuter carriers SkyWest Inc. and Trans States Holdings even as its debut was delayed by more than a year.

SkyWest and Trans States said Thursday they are in talks about a new timetable with MHI's aviation unit, Mitsubishi Aircraft Corp., after the Nagoya-based plane maker pushed back deliveries of the 78- and 92-seat models until the second quarter of 2017 from March 2016.

The postponement adds to MHI's struggles as it tries to challenge regional jet builders Bombardier Inc. and Embraer SA. It is at least the second delay after the company said in April 2012 that the first flight would be late as it confirmed fabrication processes and completed technical studies.