Toshiba Corporation has announced the resignation of chief executive Satoshi Tsunakawa with immediate effect. He is replaced by Chief Digital Officer Taro Shimada, who previously headed the company's digital solutions arm. The Toshiba board has stated that Shimada's appointment is interim and the possibility of appointing an external candidate still stands. Tsunakawa remains as chair of the board.

Tsunakawa's resignation appears to be the result of massive shareholder discontent over restructuring plans announced last year. Under those plans, the electronics giant would break up into three separate companies, comprising two of its major businesses - infrastructure and devices - and a third that would invest in flash memory chips. However, there was so much opposition from shareholders that in February, the restructuring was scaled back to only spin off the device business.

Toshiba's announcement downplays Tsunakawa's departure, but Japanese media has widely speculated that he is resigning to take responsibility for the confusion around the restructuring, and possibly to appease shareholders. The new interim management may also review the entire idea of restructuring in the first place.

This is the second time in as many years that a Toshiba CEO has stepped down amid board and shareholder displeasure. Last April, then-CEO Nobuaki Kurumatani resigned over a $20 billion buyout bid that shareholders suspected was meant to paper over a corporate governance scandal where the company was accused of suppressing foreign investors' rights, and chairman Osamu Nagayama was subsequently forced out in the scandal's aftermath. Tsunakawa, who took over as chair as well as CEO, reportedly said at the time that he wanted to complete his mission in the role quickly and hand over to the next generation - although he may not have expected to hand over in such a manner.