SHENZHEN B shares were mixed on light trade, with activity concentrated on the two ports, Chiwan Wharf and Shekou Port. The Shenzhen CLSA B index rose 1.4 per cent to 780.72 points on trade worth HK$2 million after the market was closed on Wednesday. Shekou Port and Chiwan Wharf are favourites with foreign investors due to southern China's booming foreign trade. Shekou gained 11.8 per cent to $4.70, while Chiwan Wharf rose 0.3 per cent to $3.51 in light trade. Both companies are expected to benefit from an increase in fertiliser imports, as Chinese output falls short of demand. Southern Glass was the next most active stock, down slightly by 0.4 per cent to $4.53. Few fund managers are willing to invest in Shenzhen because of its low trade volumes. The CLSA Shenzhen A-30 index fell 0.24 per cent to 1,086.95 points.