EXCLUSIVE-Toshiba top investor calls for probe as vote counting scandal widens

* Investor outcry over uncounted votes at Toshiba meeting in July

* Banks now say uncounted votes found at more than 1,300 firms (Adds Sumitomo Mitsui)

By Makiko Yamazaki

TOKYO, Sept 24 (Reuters) - Toshiba Corp's top investor has called for a probe into a botched shareholder meeting, alleging several investors were deprived of their vote, a letter to the Japanese conglomerate's board seen by Reuters shows.

The letter may help keep focus on governance at Toshiba, even as the bank hired to count the votes, Sumitomo Mitsui Trust Bank, and another, Mizuho Trust, revealed details of counting errors affecting more than 1,300 firms.

Singapore-based Effissimo Capital Management, which owns around 10% of Toshiba, is the latest investor to join the outcry over the July 31 meeting, which has drawn attention to concerns about governance and treatment of foreign shareholders.

The letter from Effissimo comes after Toshiba this month said more than 1,000 postal voting forms for its shareholder meeting went uncounted. Another Singapore-based fund, 3D Investment Partners, has already called for a similar investigation, saying its vote had not been fully recognised.

Effissimo said Toshiba's board should establish a committee made up exclusively of independent members to investigate whether the July meeting was conducted fairly.

"We have surveyed several dozen shareholders regarding this matter, and were able to confirm that there are in fact several shareholders that were unable to vote in a manner consistent with their intentions," Effissimo said in its letter, which was dated Sept. 23.

Effissimo and Toshiba both declined to comment when contacted by Reuters.

BOTCHED MEETINGS

What started out as a problem at Toshiba has widened into a larger issue for corporate Japan over shareholder vote counting.

Sumitomo Mitsui Trust Bank, which was entrusted with counting the shareholder mail-in votes for the Toshiba meeting, said on Thursday it had found 3.4 million uncounted shareholder votes at 975 client firms.

The bank said the uncounted votes would not have impacted the results of any shareholder meetings. Still, the scale of the miscounting is likely to give investors pause.

Separately, the trust banking arm of Mizuho Financial Group said it had found 22,848 voting forms were uncounted at 371 shareholder meetings where it had been involved in the counting.

It conducts vote counting in a joint venture with Sumitomo Mitsui Trust. (Reporting by Makiko Yamazaki and Takashi Umekawa; writing by David Dolan; editing by Jason Neely & Shri Navaratnam)