TOKYO (Reuters) - Lockheed Martin Corp, the maker of the F-35 jet, will help Japan build a new stealth fighter plane its air force wants to field by the mid-2030s to keep pace with aircraft technology advances made by neighbouring China. Lockheed will partner with project leader Mitsubishi Heavy Industries (MHI) , Japan’s Ministry of Defence said in press release on Friday, reforming a partnership that developed Japan’s last jet fighter, the F-2, three decades ago. “In order to ensure interoperability with the United States we will begin this project together from next year,” the ministry said. The new fighter, which is known as the F-3 or F-X and is expected to cost about $40 billion, will replace the F-2. Lockheed had proposed a hybrid design based on its F-35 and F-22 jets, but Japan rejected that in favour of a home-grown design. Other foreign firms that had expressed an interest in participating in the F-3’s development include F-18 Super Hornet builder Boeing Co and Northrop Grumman Corp from the United States, as well as Britain’s BAE Systems Plc and engine maker Rolls-Royce Holdings Plc. Japan said it would continue to seek cooperation on the F-3 with both Britain and the United States to gain access to technology and help lower development costs.