(Adds Evergrande and investor comment, market reaction) HONG KONG/SHANGHAI, Aug 17 (Reuters) - China Evergrande Group chairman Hui Ka Yan has stepped down as chairman of flagship unit Hengda Real Estate Group, a posting on the National Enterprise Credit Information Publicity System showed on Tuesday. Zhao Changlong, previously a company director, will replace Hui as chairman, and will also be general manager. Zhao is also a deputy chairman and general manager at another unit, Evergrande Property Services. Evergrande said the change was “normal” and due to the termination of a plan to gain a listing for Hengda on China’s A-share market by buying an already listed company, and it did not involve any change in management or shareholding structures. It added Zhao had been Hengda’s chairman and general manager before August, 2017. Investors have been concerned about Evergrande’s financial health and the potential systemic financial risk it poses, and there is increasing speculation that Evergrande may head to a restructuring. “My first feeling is (it’s) credit negative as the most influential guy in the company has stepped down,” said Clarence Tam, fixed income portfolio manager at Avenue Asset Management in Hong Kong. An analyst at a rating agency, who declined to be named because the comment is not official, said the personnel change could trigger covenants of Hengda’s debt, and pave way for a restructuring at Evergrande Group. Shares in Evergrande companies slumped on the news. China Evergrande Group slipped around 4%, Evergrande Property Services fell more than 8% and China Evergrande New Energy Vehicle Co dipped 5% in afternoon trade. Evergrande bonds were also hit, with bids on Evergrande’s 6.98% January 2023 bond falling to 57 yuan from above 61 yuan earlier in the day. (Reporting by Andrew Galbraith in Shanghai and Clare Jim in Hong Kong; Editing by Clarence Fernandez and David Evans) Our Standards: The Thomson Reuters Trust Principles.