SHANGHAI B shares, reserved for foreigners, rose for a seventh day in moderate trading, trailing the surging market for A shares. The A-share rise does have some impact on B shares, especially when companies offer both types of share, said Lawrence Ang, an analyst with SBCI Finance Asia. The Credit Lyonnais Shanghai B-share index rose 3.97 points, or 0.48 per cent, to close at 824.30 on turnover valued at US$5.2 million, against $5.31 million on Tuesday. Bloomberg reported that 11 stocks rose, seven fell and 10 were unchanged. The A-share index made another leap, putting on 516.19 points, or 22.39 per cent, to close at 2,822.10. Polyvinyl chloride and caustic soda manufacturer Chlor Alkali was the day's most active stock, gaining 6.4 per cent to 30 cents, with 1.7 million shares traded. ''A lot of securities firms are pushing this stock, essentially because it is so cheap,'' Mr Ang said. Chlor Alkali shares are still trading at a 57 per cent discount to their August 1992 issue price of 70.9 cents. ''The company suffered from poor earnings for a couple of years but now appears to be on the right track,'' he said. Chlor Alkali is still negotiating with German chemical giant Bayer on the possibility of forming a joint venture, a move that has boosted interest in the company, traders said. Hotel stock Jinjiang Tower fell 1.4 per cent to 71 cents, with 165,400 shares traded. Occupancy rates at the hotel have fallen below forecasts in recent months, partly because tourist arrivals from Taiwan have slumped after the murders of a group of Taiwanese visitors earlier this year.