The Hong Kong stock exchange has revealed it investigated nearly 8,000 cases of suspicious share-price movements last year. However, no action has so far been taken in any of the cases, Hong Kong Exchanges and Clearing (HKEx) confirmed yesterday. The exchange also confirmed that last year only two companies were publicly censured for improperly disclosing price-sensitive information in 1998 and 1999 respectively. The figures were revealed after Democratic Party legislator Martin Lee asked the Government to find ways of strengthening information disclosure rules. In a written reply, Secretary for Financial Services Stephen Ip said that last year the exchange had made about 7,800 inquiries to listed companies on unusual stock price movements. However he said the investigation found 'such movements arose from many factors and in many cases were not instances of possible selective disclosure.' About 3,000 clarification announcements were made by the relevant companies due to the exchange's inquiries, he said. According to listing rules, any information which might be expected to affect a stock price should be released immediately to ensure market transparency. However, there are frequently unusual price movements in the stock market, which raise fears about possible insider trading. It is thought that some companies' managements leak price-sensitive information selectively before formal announcements are made. Mr Ip said he believed the listing regulations worked well and met the needs of market development. He said the rules should be reviewed and revised from time to time, but that there was no intention of giving them statutory backing. The exchange can only censure or reprimand a company, not send a case to the courts. Mr Ip said it was important to maintain transparency so that investors could have timely access to any information which was likely to have a significant effect on the price of shares. But the listing rules would lose flexibility if they were provided with statutory backing, he said. 'As the existing listing rules are enforced by the exchange, they allow cases to be dealt with more expeditiously than by legal proceedings,' Mr Ip said. He said the exchange and the Securities and Futures Commission were conducting a comprehensive review of the listing rules, including streamlining of disciplinary procedures and ways to enhance sanctions. Separately, legislator Sin Chung-kai said he believed that the regulatory role of HKEx should be shifted to the Securities and Futures Commission because the SFC would be more independent. He said he feared a conflict of interest could evolve for HKEx as both a lister and a regulator.