THE rumour mill of the Shanghai Stock Exchange generated its tales as usual, despite last week's release of new rules aimed at controlling the spread of information, according to brokers. A Shanghai broker said: 'The regulations have come out, but rumours are sweeping the trading floor as usual. Today, the focus of attention is that Shanghai Lujiazui Finance and Trade Zone will post a high net asset value.' The Pudong development company, which has A shares listed in Shanghai, is to release today its B shares prospectus, which investors expect will reveal financial information such as net asset value. 'The company's A shares rose three per cent today on the rumour, which can by no means be eradicated in the market,' said the broker yesterday. He speculated the rules came about to address a small group of people who were taking advantage of connections with government officials to profit from the stock market, cashing in on the rumour-turned-news tales. However, he believes the Rules Concerning the Management of Information on the Stock Market - issued jointly by six Shanghai authorities on Thursday - have uses and ought to be enforced without delay. 'To a certain extent, the regulations will serve to shore up control of the spread of information and provide the base for investor protection - although they apparently were vague,' he said. Another broker agreed. 'There are many publications in Shanghai spreading rumours, and there are people making use of the media and salons [discussion forums] to spread false information. Something should be done to stop this.' However, the broker conceded that the 17-point regulations could only be expected to curb the number of irresponsible practices, and not root them right out of the emerging stock market. He said some smaller publications no longer appeared in newspaper stands but were being wrapped up in a new form. 'It's definite that these things can in no way be stamped out.' Both brokers said they were not afraid of releasing information since the issue of the new rules because their opinions were always 'objective'. Yesterday, the Shanghai A stock index edged slightly lower to 690, down eight points from Friday's closing. Shanghai authorities are reportedly investigating the source of rumours about the health of China's paramount leader Deng Xiaoping, which sent the market tumbling early last month.