THE Hongkong stock market's summer lull is well and truly underway, with no positive news in sight and turnover set to remain low, brokers say. Last week saw the Hang Seng Index fall 145.39 points with turnover drying up to $2.69 billion on Friday. The listing of Tsingtao Brewery, the first of nine mainland companies planning flotations on the Hongkong market, was the source of some light relief on Thursday, dominating trading on its first day. However, brokers say the listing of the second Chinesecompany, Shanghai Petrochemical, is unlikely to have a similar effect given its unpopularity among international brokerage houses. What little activity there was in the market last week was focused on red-chip stocks. One broker suggested mainland interests were behind the buying in an attempt to ensure that the Shanghai Petrochem offer was successful. ''Buying in red chips and the action in the futures market is a result of mainland participation. They are trying to make the market look attractive and make sure it is in a positive frame of mind for the listing,'' said one broker. Brokers have been wary of Shanghai Petrochem since the details of the company were issued in its prospectus two weeks ago. ''Its machinery is 20 years old, it has no competitiveness in international markets, the company's information is not up to standard and few international houses are recommending it, especially in this market environment,'' said one broker with a European house. Meanwhile, brokers said the political concerns which have been holding the market back have not changed, and with little prospect of any breakthrough between Britain and China over Hongkong's future, they expected the market to continue to stagnate. ''We could be in for a further period of inactivity while the political side sorts itself out,'' said James Slade, assistant director with Baring Securities. ''Sentiment is somewhat neutral,'' he said. ''A lot of brokers and fund managers are on holiday at the moment, and there is no news in this market anyway, so the index is probably going to drift for a while,'' said another broker. Analysts said that the Hang Seng Index could come off 300-400 points before institutions take a strong position in the market again.