The request came from Singapore-based 3D Investment Partners, which owns 19.4% of Fuji Soft according to Refinitiv data and is also Toshiba Corp's second-largest shareholder.

According to Fuji Soft's filing, 3D said the company would need to add external directors to enhance oversight as current management's lack of awareness over capital costs had resulted in sluggish performance.

At an annual shareholders' meeting in March, 3D also proposed bringing its two nominees on to the board. One of the nominees received support of nearly 40% of shareholders despite Fuji Soft's opposition.

3D, which had held roughly 9% at that time, has doubled its stake since then. The fund had proposed a management buyout in the past.

(Reporting by Makiko Yamazaki; Editing by Alex Richardson)