Toshiba Corp. has uncovered 10 new cases of accounting problems, including at a U.S. unit, prompting it to miss a regulator's deadline for submission of its fiscal 2014 earnings release.

The industrial group obtained permission from the securities regulator to postpone the report due Monday until Sept. 7. President Masashi Muromachi, who took charge after three of his predecessors left following a July third-party report on accounting practices at the company, had said he might quit if the new deadline was missed.

The second delay of earnings, initially due in May, comes after internal and external probes of the industrial group's accounting led to the resignations and caused at least ¥145 billion in writedowns. Toshiba said Monday it discovered irregularities in percent-of-completion accounting related to a U.S. hydro-power unit's construction project.

"One week delay is not such a big deal, but that's another week of uncertainty," said Hideki Yasuda, an analyst at Ace Research Institute in Tokyo. "They need to report as soon as possible."

Toshiba said in August it expected a net loss for the past year without providing a specific number as costs related to the scandal wiped out profit from its businesses, which span nuclear reactors, computer memory chips and laptop computers. The company has revamped its board, apologized to investors and appointed a special committee to try to win back trust and prevent further irregularities at the 140-year-old pillar of Japan Inc.

The company has lost a quarter of its market value this year.

Toshiba on Aug. 18 forecast operating income of ¥170 billion for the year ended March 2015 and pretax profit of ¥140 billion. The company had scrapped its earnings forecasts in May and announced an investigation of accounting irregularities that was subsequently expanded to cover the entire company.

The company, which has built up holdings in more than 300 affiliates, partners and customers, has said it will sell some of them off to raise cash.

Toshiba will sell its stake in Topcon Corp. and expects to book a gain of between ¥30 billion and ¥40 billion, it said separately Monday. The company has submitted the financial results to its auditor, it said in a separate statement.

Muromachi also apologized to shareholders at a briefing Monday night in Tokyo. Toshiba said Westinghouse was not the U.S. unit being probed.

Toshiba's third-party report released July 21 detailed practices that led to overstatement of profits, linking them to former Presidents Hisao Tanaka, Norio Sasaki and Atsutoshi Nishida. Muromachi's name wasn't mentioned.

Toshiba also announced board changes this month, increasing the number of independent directors to seven from four. No charges have been filed against Toshiba or its executives.

"The company has completely lost investor trust, since no one had expected things to be this bad," said Yasuaki Kogure, chief investment officer at SBI Asset Management Co. "We still don't know whether the new management will change the company and how, and what it will consider as an achievable profit margin."