Mitsubishi Aircraft Corp. had a negative net worth of ¥51 billion at the end of March, according to the government's official gazette.
Mitsubishi Aircraft, a subsidiary of Mitsubishi Heavy Industries Ltd., has seen costs surge from delays in the development of its new regional jet, Japan's first domestically developed airliner.
The subsidiary posted a net loss of ¥51.1 billion in the year ended March with cumulative losses totaling ¥151 billion.
The development costs are expected to reach ¥500 billion, about triple the initial estimate, because of the delays and the hiring of more engineers than initially planned.
The state-owned Development Bank of Japan owns a 1 percent stake in Mitsubishi Aircraft and Mitsubishi Heavy holds a 64 percent stake. Mitsubishi Corp. and Toyota Motor Corp. are among the other major shareholders.
Mitsubishi Aircraft is in the midst of efforts to speed up development under Mitsubishi Heavy President Shunichi Miyanaga and said its financial condition will not affect the MRJ project.
Earlier this year, it said the schedule for the first delivery would be postponed by two years to the middle of 2020.
The fifth delay since the business was launched in 2008 was blamed on "revisions of certain systems and electrical configurations on the aircraft to meet the latest requirements for certification."