[HK stocks approach six-week high on Alibaba tailwind while Chinese coal producers slump] Hong Kong stocks reached the highest level in almost six weeks, aided by a rally in Alibaba Group Holding, amid speculation on its ties with Chinese regulatory authorities. Coal producers fell after an overnight plunge in the commodity. The Hang Seng Index gained for a fourth day, adding 1.4 per cent to 26,136.02 on Wednesday, the highest since September 10. The tech benchmark appreciated 2.7 per cent as the three biggest constituents advanced by at least 2.1 per cent. Alibaba, the owner of this newspaper, surged 6.7...