3D Investment Partners PTE, the second-largest investor in Toshiba Corp., called for a special meeting of the Japanese company’s shareholders on Thursday as it steps up opposition to a separation plan.

Singapore-based 3D is requesting a vote on Toshiba’s proposed split, which must be supported by at least two-thirds of stockholders, it said in a statement, confirming an earlier Bloomberg News report. A second proposal from 3D, which holds a 7.6% stake in Toshiba, asks for the company to reconsider alternative options.

Toshiba announced in November that it intended to separate into three companies as a way to create value for shareholders after years of scandals and corporate governance issues. 3D published an open letter that month opposing the plan, saying Toshiba’s strategic review process was inadequate.