Jan 23 (Reuters) - China Evergrande Group (3333.HK) said on Sunday it had appointed its Energy Vehicle unit"s chairman as an executive director. Evergrande said in a Hong Kong Stock Exchange filing that Siu Shawn, 50, who was chairman of the board of China Evergrande New Energy Vehicle Group Limited (0708.HK), had entered into a service contact for three years. The stock exchange filing said that Lai Lixin and Huang Xiangui had both resigned as executive directors of Evergrande. Lai had resigned as executive director to devote more time to his other duties with the group, while Huang stepped down for health reason, the filing said. Both will remain with the group. Evergrande is the world"s most indebted property company, with more than $300 billion in total liabilities, which include nearly $20 billion of international bonds all deemed to be in default after a run of missed payments late last year.