Tokyo: Toshiba shares plunged Wednesday as fears grow about the future of one of Japan's best-known firms, hit by massive losses and accounting fraud allegations at its US nuclear unit.
The Tokyo-listed stock dropped as much as 13.62 per cent at one point, with concerns that the embattled company's shares could be delisted from the bourse.
Toshiba ended the day at 189.5 yen ($1.65), down 12.22 per cent, as the benchmark Nikkei 225 index slipped 0.16 per cent.
The vast conglomerate - which has about 188,000 employees globally and annual revenue topping 5.6 trillion yen - won regulators' approval Tuesday to delay releasing its October-December earnings for another month.
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.
"The designation hit sentiment... as the bourse called (Toshiba's) internal management into question," Toshihiko Matsuno, chief strategist at SMBC Friend Securities, told AFP.
Toshikazu Horiuchi, a broker at IwaiCosmo Securities, added: "Toshiba is turning into a speculative stock. It's now just a money game."
Japanese financial regulators have given Toshiba until April 11 to publish its fourth-quarter results, which were originally due in mid-February.
Toshiba shares have been hammered this year, losing more than half their value since late December when it first warned of multi-billion-dollar losses at Westinghouse.
The probe was started after a whistleblower complained that one or more Westinghouse executives exerted "inappropriate pressure" on its accounts.
It's "hard to determine the potential bottom for the company's balance sheet given the numerous lingering uncertainties", Credit Suisse analyst Hideyuki Maekawa told Bloomberg News.
The crisis comes less than two years after Toshiba's reputation was badly damaged by separate revelations that top company executives had pressured underlings to cover up weak results for years after the 2008 global financial meltdown.
Toshiba has previously warned it was on track to report a net loss of 390 billion yen in the fiscal year to March, as it faced a writedown topping 700 billion yen at Westinghouse.
The company once touted its overseas nuclear business as a future growth driver, filling a hole left after the 2011 Fukushima crisis slammed the brakes on new atomic projects in Japan.
But cost overruns have hit Westinghouse's finances hard.
Toshiba is now dramatically reducing its nuclear ambitions overseas and plans to stop building new atomic power plants, but said it will keep making related equipment.
The cash-strapped company has sold off a number of assets, including a medical devices unit and most of its home appliance business. Its prized memory chip business is now on the block.