Olympus said it was preparing to file its July-September earnings by Wednesday, a necessary step for the disgraced 92-year-old firm to remain listed.

The Japanese maker of cameras and endoscopes also said it would hold a briefing on Thursday to explain the results, after admitting to a $1.7 billion (€1.2 billion) scheme to hide investment losses stretching back more than a decade.

The scandal has put the company's future at risk. Even if Olympus meets the earnings deadline, the Tokyo Stock Exchange can still decide to delist Olympus depending on the scale of its past misreportings.

The ousted chief executive who blew the whistle on the scheme, British-born Michael Woodford, arrives in Tokyo this week on a mission to persuade employees and shareholders he is the right person to get the company back on track. But he faces a battle with current management, who want to pick their own successors.

Olympus shares extended gains in heavy trade to hit a six-week high after the news that it was preparing to meet the December 14th deadline.

The stock was trading up 8 per cent at 1,307 yen in early afternoon trade, but the shares are still worth only about half their value before Woodford was ousted on October 14th and began his public campaign to expose the scandal.

Investors will be looking at the overall impact of the accounting restatements on Olympus' balance sheet and whether this will be sufficiently large to put the company under pressure to raise fresh equity.