Mitsubishi Aircraft Corp., the maker of Japan's first passenger jet, won an order for as many as 20 planes from a U.S. lessor, according to two people familiar with the deal.

The order is for the larger MRJ90, said one of the people, who asked not to be identified because a final decision has not been made. An order for 20 jets is valued at $946 million in list prices before customary discounts. The deal will have firm and option components, another person said.

The order gives a boost to the Mitsubishi Regional Jet, which made its maiden flight in November. The manufacturer has announced a delay of one year for first delivery until the middle of 2018. The company had 407 orders for its new aircraft, including options and purchase rights, as of the end of last year.