Toshiba Corp"s (6502.T) second-biggest shareholder called on the Japanese conglomerate to conduct a strategic review and explicitly solicit suitors, criticising the company"s comments on wanting to remain listed as deterring potential acquirers. "We call upon the board to openly welcome interest from suitors who could enhance corporate value and ask the board to conduct a formal review of strategic alternatives," 3D Investment Partners said in a letter sent to Toshiba's board on Monday and made public. "To conduct a fair and proper process, Toshiba should explicitly indicate that it is open to alternative ownership structures and correct media speculation that Toshiba's management team and board have a strong preference for remaining a listed company," 3D, which has a 7.2% stake in Toshiba, said. Toshiba dismissed last week a $20 billion buyout offer from CVC Capital Partners as lacking detail. The industrial conglomerate has said it believed that being publicly traded provided a "capital structure suitable for enhancing long term value creation" but added that its board would not disregard various proposals, including those to take the company private. Bain Capital, KKR & Co Inc (KKR.N) and Canada’s Brookfield Asset Management (BAMa.TO) are also looking at potential bids for Toshiba, Reuters has reported. Toshiba had no immediate comment on the letter. Its shares were up 0.3% at 4,425 yen by midday on Monday. In the letter, Singapore-based 3D said it estimated Toshiba's fair stock value in excess of 6,500 yen.