The record 523 million yuan ($85 million) fine may seem big, but Everbright Securities Co's troubles are far from over.

The company is facing claims estimated at 2.7 billion yuan by investors alleged to have been misled by the company's deliberate withholding of information about its 7.2 billion yuan trading mistake.

But lawyers said potential claimants may need more information from the China Securities Regulatory Commission investigation to pin Everbright down.

According to the Securities Law of China, the principal should shoulder responsibility if insider trading incurs any losses. But Liu Mingjun, director of the capital market department of Beijing Celue Law Firm, told Xinhua News Agency that there is a lack of detailed interpretation and regulations in the Securities Law.

In the United States, investors who can prove they suffered a loss as a result of insider trading would bring a civil claim against the broker responsible for it, said Gene Buttrill, capital markets practice partner at the global law firm Jones Day.

So far, the commission has only handed down the penalty with a note saying that investors who felt cheated can seek redress through litigation. It has not disclosed details of its investigation that showed how Everbright stonewalled the stock exchange on Aug 16, allowing itself time to engage in insider trading to cover its potential losses.

Following Everbright's former president Xu Haoming's resignation on Aug 22, Yang Chizhong, assistant executive, and Mei Jian, secretary of the board of directors, resigned on Saturday. Xu and Yang, together with Shen Shiguang, general manager of the accounting department, and Yang Jianbo, general manager of the strategic department, were fined by the commission and banned from any work involving the stock exchange.

Buttrill of Jones Day said insider trading cases in the US carry both criminal and civil penalties. "For serious cases, jail sentences are often appropriate," he added.

The share price of Everbright Securities plummeted 8.54 percent to close at 9.21 yuan on Monday, while the benchmark Shanghai Composite Index remained basically unchanged from the last trading day, closing at 2,098.45 points.

Media reports have said a programmer at Everbright changed the stock brokerage's internal order-placing system it had developed to cover up a malfunction before the commission's investigative team arrived on site in an attempt to put all the blame on the outside supplier of the trading system.

The allegation was supported by a company source who was quoted as saying on condition of anonymity that the "fat finger" which caused the trading error was actually two software bugs, one in the trading system provided by the outside provider and the other in Everbright's own order taking system. The commission's investigation team was back in Shanghai last week after the initial three-day investigation starting from Aug 19 after they discovered the alleged tinkering.

Everbright spent about 100,000 yuan on the supplier's trading system. Other trading system providers charge about 1 million yuan. Everbright chose the supplier because the provider was willing to program the system to Everbright's specifications and requests, the source said.

He added the strategic investment department, from where the mistaken buy order was issued, is likely to be merged into other departments or the whole team will be dismantled.

The department mistakenly sent huge buy orders valued at 23.4 billion yuan on Aug 16. Of this, a total of 7.27 billion yuan was transacted. The big buy order was widely attributed to having lifted the index 5.96 percent in three minutes.

The commission banned the company from proprietary trading for three months and suspended approval for new Everbright services.

Everbright's net profit was around 1 billion yuan last year. Interim results show that it made a net profit of 811 million yuan in the first half of this year.