Toshiba Corp may appoint more outside board members to improve oversight of its accounts which it is now investigating after finding irregularities, its CEO said on Thursday. Toshiba has not been able to close its books for the year that ended in March as a third-part committee it hired probes its book-keeping practices. The company has also skipped its year-end dividend to shareholders, who angrily challenged Chief Executive Hisao Tanaka during an annual general meeting, which lasted for a record 3-1/4 hours.