SOME CHINA watchers actually call it reading the tea leaves, trying to predict and analyse shifts in the mainland's leadership. For Kremlinologists put out of work by the fall of the Soviet Union, China is one of the few places where they can still practice their craft. Shanghai, China's financial centre, prides itself on the creation of an open and stable business environment for foreign investors. Twice in the past 10 months, however, Shanghai has shuffled its top leadership, causing some foreign investors to wonder about the possibility of policy changes. Changes to Shanghai's recipe for success are unlikely, analysts say. But more transparency in announcing changes in the city's leadership would go a long way towards reassuring investors. Xinhua news agency announced in a terse report on Tuesday that Shanghai's party chief Huang Ju had stepped down to 'transfer to a central government job'. It did not describe the job. Analysts have tipped Mr Huang as a candidate for the party's powerful seven-member standing committee, to be announced early next month. Shanghai mayor Chen Liangyu would replace Mr Huang as party secretary, Xinhua said. But will Mr Chen, a capable technocrat, remain mayor? A local government spokeswoman declined to comment when asked if she had a new boss. Then an official called back. Watch the news on Shanghai's satellite television station at 8pm, he said. The news report referred to Mr Chen as both mayor and party secretary - question answered. Sinologists point out that Mr Huang himself held both posts for a brief period in 1994-1995 before he resigned as mayor to concentrate on the party secretary job. The day after the announcement, Shanghai Daily ran this tantalising tidbit: 'Mr Chen will continue to act as mayor until a replacement is named.' It did not say when a replacement would be named, or who that might be. Shanghai's two main newspapers ran identical reports on the changes accompanied by the same photograph of Mr Huang and Mr Chen shaking hands. No editorials accompanied the stories. Mr Chen has served as mayor for less than a year but he toiled as a vice-mayor for more than five years. Shanghai's previous mayor Xu Kuangdi shocked the foreign business community by suddenly resigning last December. The former professor, well-liked for his ability and fluent English, became party chief of the Chinese Academy of Engineering in Beijing. A recent newspaper report said he would help oversee the reform of the nation's railway system, including partial privatisation. No reason was ever given for Mr Xu's move so rumours flew: a personal rift with party secretary Mr Huang, the need to improve his party standing before promotion, the whiff of other problems. Now, it looks like Shanghai is getting ready to replace another respected mayor. Mr Huang was mayor from 1991 to 1995 but never achieved the popularity Mr Xu enjoyed among foreign executives. People who have met Mr Huang describe him as shrewd and smooth with a reputation for following the party line. Mr Huang becomes one of several Shanghai officials to vault to the central government, a group which includes President Jiang Zemin and Premier Zhu Rongji. At a briefing for journalists in May to mark his reappointment as party secretary, the 64-year-old Mr Huang played to the audience by joking about his age and reeling off the ages of his colleagues to show his impressive memory. But he left the meeting without straying from the script, answering a single question, or lingering to take tea with reporters as officials had promised. In his first meeting with Hong Kong media since taking office as mayor, Mr Chen spoke easily for 1.5 hours, frequently asking his subordinates to provide information or clarify details. But he did not take any questions either. In his annual meet-the-press gathering, former mayor Mr Xu answered questions directly and revealed personal information like his favourite Web sites - Yahoo! and Eastday.com, set up by Shanghai media. There are obvious contrasts in the styles of Shanghai's last three mayors but diplomats say all were capable officials who made the development of the city their top priority. Shanghai's future mayors will face big challenges. The city has aspirations to become an international financial centre but strict government controls on capital flows make that difficult. Shanghai wants to become a regional aviation hub but will have to improve transport links to the new Pudong International Airport and catch up to other Asian cities. The city aims to topple Beijing as the art and culture capital of China but local authorities keep a tight grip on artistic expression. Shanghai must balance replacing dilapidated housing with protecting historic buildings. It must tackle traffic congestion while raising incomes so more people can afford to buy cars. The city needs to boost the economy while controlling the pollution that results from uncontrolled development. And Shanghai needs to become an international city while preserving the characteristics that make it unique.