TOKYO -- Mitsubishi Aircraft on Friday said it has agreed with Eastern Air Lines to cancel the U.S. carrier's order for 40 Mitsubishi Regional Jets.
Mitsubishi Aircraft has received orders for around 450 MRJs.
According to the Mitsubishi Heavy Industries unit, the cancellation "will not affect" delivery of other jets.
Mitsubishi Aircraft, which has pushed back its first deliveries five times already, now expects to ship its first jets in 2020.
Eastern Air last year was purchased by rival Swift Air. Eastern then lost its airline license.
The carrier ordered the passenger jets four years ago, and delivery was originally scheduled to start in 2019, but Mitsubishi Aircraft has twice pushed back the date, which had been up in the air before the cancellation.
The Japanese company is now anxious about other orders, like one from SkyWest of the U.S. for 200 aircraft.
The MRJ made its maiden test flight in 2015 and has been taking to the air for further tests in the U.S. since then.
Last January, however, Mitsubishi Aircraft was forced to announce a fifth delay, saying the MRJ failed to be certified as airworthy by the U.S. Federal Aviation Administration.
Since then, other makers of regional jets have been heaping pressure on Mitsubishi Aircraft. Brazil's Embraer, regarded as the biggest player in the space, is in tie-up negotiations with Boeing. Canada's Bombardier has already joined hands with Airbus. And a Chinese company, Comac, has introduced its own regional jet.
In Japan, the fate of the MRJ program -- the first effort to produce a domestic passenger aircraft in about a half century -- is a matter of national pride. Amid all the media attention, there are hopes that the jet can debut in time for the 2020 Tokyo Olympics.
Mitsubishi Heavy Industries has decided to act. It has brought the problem-ridden Mitsubishi Aircraft under the direct supervision of its president, Shunichi Miyanaga. The parent company also plans to hire aircraft engineers away from U.S. makers so that they can help the MRJ win certification by the end of next year.