TOKYO—Toshiba Corp’s proposal to split itself into three companies won’t solve its governance issues and the conglomerate should prioritize an overhaul of its board and management, said a senior executive at one of Japan’s largest pension funds. Ken Hokugo, corporate governance director at the Pension Fund Association (PFA), said the interests of Toshiba management and shareholders are “not aligned.” “The most orthodox solution to the discrepancy is to bring onto the board someone who can monitor and discipline management, and to let the revamped board select the new chief executive,” he said in written responses to Reuters queries. Hokugo declined to comment on how the PFA, which owns an undisclosed amount of shares in Toshiba, would vote on the conglomerate’s plan to break up into three companies—one for energy and infrastructure, another for electronic devices, and a third to house its flash memory chip assets. Nonetheless, his comments highlight broad …