SHANGHAI, Aug 17 (Reuters) - China Evergrande Group chairman Hui Ka Yan will step 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. (Reporting by Andrew Galbraith and Clare Jim; Editing by Clarence Fernandez) Our Standards: The Thomson Reuters Trust Principles.