Toshiba shares plunged Wednesday afternoon as fears grow about the future of one of Japan's best-known firms, which is battling massive losses and accounting fraud allegations at its US nuclear unit.

The Tokyo-listed stock dropped 13.62 percent to 186.5 yen with concerns growing that the embattled company's shares could be delisted from the bourse.

The vast conglomerate -- which has about 188,000 employees globally and annual revenue topping 5.6 trillion yen -- won regulatory approval Tuesday to delay releasing its fourth-quarter earnings for a second time.

Toshiba said it needed more time to probe claims of misconduct by senior executives at atomic power unit Westinghouse Electric and gauge the impact on its finances.

The Tokyo Stock Exchange has put Toshiba "under supervision" over concerns about its internal management controls, a designation that means the stock is at risk of being delisted -- a major embarrassment for a pillar of corporate Japan.

source: AFP