Japan wants to develop a stealth fighter domestically, rejecting designs from Lockheed Martin Corp. and Boeing Co. in the United States and Britain*s BAE Systems PLC, three sources with knowledge of the program said.

That would put Japan*s leading defense contractor, Mitsubishi Heavy Industries, in the lead for a military contract worth more than $40 billion (?4.3 trillion). The company has not submitted a design for the next-generation jet but developed Japan*s stealth fighter technology demonstrator, the X-2, in 2016.

※Japan*s stealth designs have performed well in tests so far,§ said one of the sources, who has knowledge of discussions on the proposed plane, which is referred to as the F-3 or F-X.