By Tim Kelly and Nobuhiro Kubo
TOKYO (Reuters) - Northrop Grumman Corp <NOC.N> is eyeing a Japanese jet fighter project that could pit it against Lockheed Martin Corp <LMT.N>, three sources said, almost three decades after it lost a similar competition to build an advanced stealth jet for the U.S. Air Force.
"Northrop is interested," said one of the sources, who has direct knowledge of the plans. Northrop has already responded to Japanese requests for information (RFI) and has held preliminary talks with Japanese defence industry officials, he said.
Northrop Grumman has provided Japan with a menu of technologies it could contribute to the next-generation F-3 fighter project, but not yet made any specific proposals to Japan, the sources said.
The sources declined to be identified because they are not authorised to speak to the media.
The company's bid would compete with Lockheed Martin proposals that include a hybrid stealth design based on its F-35 Lightning II and F-22 Raptor. The F-22 beat Northrop's YF-23 Black Widow demonstrator to win the lucrative U.S. Advanced Tactical Fighter contract in 1991.
The F-22 is banned for export and is only used by the U.S. Air Force. But Japan has ordered 42 F-35s to upgrade ageing fighters whose designs date back to the 1970s. It plans to increase that order, including purchases of the vertical take off and landing (VTOL) versions suitable for aircraft carrier operations.
Northrop Grumman was unable to immediately comment.
Both it and Lockheed Martin would need U.S. government approval to offer sensitive aircraft technology to Japan.
Tokyo has also sought offers from Boeing Co <BA.N>, which makes the F/A-18E/F Super Hornet, and has sounded out European defence companies about possible cooperation, including BAE Systems PLC <BAES.L>, which is a leading member of the consortium that built Europe's Typhoon high-altitude interceptor.
The British company has also provided Japan's Ministry of Defence with a list of technology it could contribute, a fourth defence industry source said.
Bringing in foreign partners would allow Japan to spread development costs, estimated to be around $40 billion (30.23 billion pounds), and give it access to technology it would otherwise have to develop from scratch.
Tokyo, however, wants to ensure Japanese companies provide the F-3's avionics and flight hardware, which include communication and navigation systems, radar, and engines that are being developed by IHI Corp <7013.T>.
The Japanese government has so far issued three RFIs for the F-3 and sent letters to the British and United States governments outlining its requirements in more detail, sources have told Reuters.
Any foreign company picked for the F-3 project will work with Japanese defence contractor Mitsubishi Heavy Industries Ltd <7011.T>.
The maker of the A6M Zero, which battled Grumman Hellcats and Wildcats over the Pacific in World War Two, last developed a jet fighter two decades ago. That plane, the F-2, was a joint effort with Lockheed Martin.
Mitsubishi Heavy also assembles Japan's F-35s, a programme to which Northrop Grumman contributes components such as wing skins. The U.S. company's other military aircraft include the E-2 Hawkeye airborne early warning aircraft and the Global Hawk unmanned aerial vehicle (UAV), both of which Japan has purchased.
Northrop Grumman built the B-2 Spirit stealth bomber and is developing the new B-21 stealth bomber for the U.S. Air Force. Its last fighter aircraft was the F-14 Tomcat, retired in 2006 from the U.S. Navy but still in service with the Iranian air force.
For now, it is unclear when Japan will begin F-3 development, as Japanese officials juggle spending priorities and military planners mull designs. Defence officials would like to introduce the aircraft in the mid-2030s to deter Chinese and Russian airspace intrusions.
With many of the engineers who designed the F-2 reaching retirement age, Japan, according to a fifth source familiar with Japanese defence industry capabilities, will need to get the project under way within the next two years to ensure it still has the skills to build a fleet of advanced stealth jets.
(Reporting by Tim Kelly and Nobuhiro Kubo; Editing by Gerry Doyle)