UPDATE 1-Sumitomo Mitsui Trust finds uncounted shareholder votes at 975 client firms

(Adds Mizuho Trust statement)

TOKYO, Sept 24 (Reuters) - Japan’s Sumitomo Mitsui Trust Bank said on Thursday it had found about 3.4 million uncounted shareholder votes at 975 clients, after revelations of a botched count at Toshiba Corp’s annual meeting.

Sumitomo Mitsui, entrusted to count votes for Japanese companies’ shareholder meetings, said last week it mistakenly omitted some votes from a final tally at a Toshiba shareholder meeting.

While Toshiba and Sumitomo Mitsui have said the error did not affect the outcome of the meeting, it raised fresh questions about Japan’s corporate governance, with foreign and minority investors increasingly demanding to be heard.

Sumitomo Mitsui said it would hold a news briefing on this matter at 5 p.m. JST (0800 GMT).

Separately, the trust banking arm of Mizuho Financial Group Inc said it had found 22,848 voting forms were uncounted in 371 clients’ shareholder meetings.

Vote counting at Mizuho Trust is done in a joint venture with Sumitomo Mitsui Trust. (Reporting by Takashi Umekawa; editing by Chang-Ran Kim and Jason Neely)