While Mitsubishi Aircraft Corp. has clinched a deal to deliver its new small passenger jet to All Nippon Airways Co. in 2017, Japan Airlines Co., the country's other major carrier, has yet to sign up for the plane.

Gaining JAL as a customer would be seen as an endorsement by the Japanese aviation industry for the first domestically built small jet, dubbed the MRJ, or Mitsubishi Regional Jet.

To win over JAL, Mitsubishi Aircraft needs to overcome competition from Brazil's Embraer S.A., which has been supplying JAL with small, or "regional," jets.