Towngas of Hong Kong is in talks to invest US$100 million initially in a coal gastification joint venture in Shanxi province as the compnay mulls diversification in the Mainland, The Standard reported. Shanxi is a major coal-producing province and has an abundance of reserves.   Towngas is following in the footsteps of two Hong Kong-listed companies, electricity supplier Enerchina and piped gas distributor Xinao Gas. These companies plan to take majority stakes in three coal mining companies in Inner Mongolia, Yunnan and Heilongjiang, to pave the way for coal gasification projects, wrote The Standard.   Macquarie Research said in a June report that another two projects are to be finalized this year. "In 2005, the profit contribution from China grew by 82 percent to HK$240 million, representing around 6 percent of profit. The company now has over three million gas customers in China compared with around 1.6 million in Hong Kong. By 2008, we expect China to account for 15 percent to 20 percent of the bottom line," said analyst Rohan Dalziell of Macquarie Research to the paper.