TOKYO, Dec. 13 (Kyodo) — Mitsubishi Heavy Industries Ltd. said Thursday its Mitsubishi Aircraft Corp. unit has signed a contract to provide SkyWest Inc. of the United States with 100 Mitsubishi Regional Jet aircraft worth $4.2 billion from 2015.

SkyWest, which owns two regional airlines in the United States, also put an option on another 100 MRJ jets.

If the option is implemented, Mitsubishi Aircraft will deliver the 100 MRJs from 2021.

Mitsubishi Aircraft was founded in 2008 to develop the MRJ with 70 to 90 seats.