TOKYO - Olympus said on Tuesday that it was suing 19 current and former executives and board members, including its current president, for almost $50 million over an accounting scheme to hide losses going back more than a decade. But in the latest indication that the Olympus scandal continues to follow a distinctly Japan Inc. approach to corporate governance, the company is letting the discredited president and the implicated board members stay on until later this year. The president, Shuichi Takayama, was a long-time lower-level Olympus executive and board member until last November, when he was promoted to replace Michael C. Woodford, a Briton. Mr. Woodford was fired after blowing the whistle over the $1.7 billion accounting fraud. Olympus said on Tuesday that Mr. Takayama, who has contended he knew nothing of the scheme, was being sued for 500 million yen, or about $6.5 million, on contentions that he failed to meet his fiducuiary duties as a director while the fraud was under way. Olympus shares jumped nearly 30 percent on the announcement Tuesday, as investors bet that by taking legal action against those implicated in the scandal the company could head off a threatened delisting by the Tokyo Stock Exchange. Still, some critics and analysts warned that keeping tainted executives at the helm of Olympus threatened to undermine its turnaround effort by allowing discredited board members to name their successors and subvert meaningful changes in the management and accounting oversight of the company. Olympus, a maker of cameras and medical optical devices called endoscopes, remains in dire need of fresh capital after recently restated accounts showed its shareholder equity at far lower levels than previously disclosed. Olympus on Tuesday defended its move. Olympus has admitted to concealing losses dating back to the 1990s using an elaborate scheme involving offshore funds. The case has cast a harsh spotlight on lax corporate governance in Japan. That admission came after Mr. Woodford, who became president last April and chief executive in August, blew the whistle on fraudulent accounting at the company. He went public with his allegations after being fired in October. Olympus had initially said it fired Mr. Woodford, one of a handful of foreign executives at top Japanese companies, over what it called his aggressive Western management style. But Mr. Woodford disclosed internal documents to show he had been dismissed after he raised questions about irregular payouts related to mergers and acquisitions. Olympus later acknowledged that those payments, made from 2006 through 2008, were part of a scheme to own up to losses on past investments that it had long kept off its balance sheets. The scandal has led to government investigations in Japan, the United States and Britain. And Olympus appointed an outside panel to investigate the matter. Mr. Woodford later made a bid to return to the company with a fresh slate of directors, but he abandoned that effort last week after Japanese institutional investors continued to back Olympus's current management. Meanwhile, Olympus's external panel has sought to identify which of its officials were involved in the scheme. On Tuesday, Olympus said the panel had implicated 19 executives to varying degrees. Based on the panel's findings, Olympus said it was seeking up to 3.6 billion yen, or $47 million, in damages from 19 past and present executives. The brunt of the damages sought will be from the former chairman, Tsuyoshi Kikukawa; the former executive vice president, Hisashi Mori; and the former internal auditor, Hideo Yamada, the company said. A separate third-party investigative panel appointed by Olympus said last month that the three had orchestrated the scheme to mask investment losses. Among current executives, besides Mr. Takayama, the company said it was suing five of eight current internal directors and one of its three current external directors. Those directors would resign at an extraordinary shareholders" meeting scheduled for March or April. The directors not named in Olympus's lawsuit are expected to keep their seats on the board. Mr. Woodford, the ousted president, said Tuesday via e-mail that the entire board had been discredited when it fired him instead of investigating his allegations and that all directors needed to go. "It is completely the wrong basis to revitalize Olympus," Mr. Woodford said. The only way forward is an entirely new board of directors, untainted by the past scandal. Southeastern Asset Management, an American firm that is Olympus's biggest overseas stockholder, has also urged the company to purge its current management.