TOKYO, March 31 (Reuters) - Japanese stocks fell on Wednesday as investors sold financial shares due to growing uncertainty over the fallout from the margin calls that brought down New York-based hedge fund Archegos Capital. The Nikkei 225 Index ended 0.86% lower at 29,178.80, while the broader Topix dropped 1.21% to 1,954.00. Mitsubishi UFJ Financial Group Inc fell 3.87%. The bank said after the market close on Tuesday that it may suffer losses of around $300 million at its European subsidiary related to a U.S. client that it did not name. The warning about losses came only a day after Nomura Holdings stunned investors by flagging a potential $2 billion loss from a single U.S. client. Nomura’s shares fell 2.9%, down for a third straight session. “Opinion is divided between those who say this is a problem confined to one hedge fund and those who warn of even more losses,” said Ayako Sera, a market strategist at Sumitomo Mitsui Trust Bank. “It is perfectly understandable that investors would want to lighten some of their positions in financial shares.” Global investment banks including Nomura and Credit Suisse may lose more than $6 billion as lending to Archegos for equity derivatives trades soured, sources said. However, there is still a degree of uncertainty about the true scale of the problem, which could continue to weigh on financial shares, analysts said. The Topix sub-index for banks fell 3.2%, which was the biggest decline in a week. The sub-index for brokerages also dropped 2.1%. Hitachi Ltd fell 7.30% after the Nikkei newspaper reported the company will buy a U.S. software developer for $9.6 billion. Hitachi confirmed the acquisition after the closing bell. In the positive territory, Toyota Motor Corp advanced 3.04% as the yen’s decline to a one-year low against the U.S. dollar boosted shares of major exporters. For Japan’s 2020/21 fiscal year, which ended on Wednesday, the Nikkei rose 54.2%, which was the biggest gain since fiscal 1972/73 and highlighted a strong recovery from the shock caused last year by the coronavirus pandemic. (Reporting by Stanley White, Editing by Sherry Jacob-Phillips)