Authorities in Beijing have removed Zhou Daojiong as head of the China Securities Regulatory Commission (CSRC) and installed conservative securities expert Zhou Zhengqing in his place, mainland traders say. There are unconfirmed rumours the authorities are planning to remove Shanghai exchange general manager Yang Xianghai and Shenzhen general manager Zhuang Xinyi as part of the reshuffle. The move is the most serious indication to date of Beijing's desire to rein in the overheated stock markets after an increase in stamp duty on transactions earlier this week failed to halt speculative activity. Analysts said Mr Zhou Daojiong's departure from the regulatory body at a time when the markets were smashing turnover and price records signified the urgency with which Beijing wanted to stem the buying frenzy. Mr Zhou Zhengqing is currently director of the State Council Securities Committee, the country's securities policy-making body, and a State Council deputy secretary-general. He has a ministerial rank, while the job as chief regulator is of a vice-ministerial level. Mr Zhou Daojiong took over the CSRC helm from Liu Hongru in 1995. 'This is probably the first time the CSRC will be headed by someone with ministerial rank, and signifies Beijing's determination to rein in the runaway Shanghai and Shenzhen markets,' a Shanghai trader said. A Beijing source said economic tsar Zhu Rongji was behind the reshuffle, as he wanted someone who was cautious but familiar with the workings of the markets to deal with the problems at the two exchanges. Mr Zhou Zhengqing, 62, worked previously with Mr Zhu when the vice-premier was also head of the central People's Bank of China. 'He is generally known as a cautious, conservative and steady guy. Mr Zhu probably appreciates these qualities in him,' a Shanghai trader said. Despite repeated warnings to brokerages, listed companies and exchanges to tighten supervision and regulation, market irregularities remain rampant. Prices of the two markets have gone up by about 50 per cent since January, as investors believed Beijing would not take drastic action to dampen the bull run in the run-up to the Hong Kong handover and the 15th Chinese Communist Party congress in autumn.