✔ 最佳答案
Please allow me to answer in English as I don't know Chinese typing.
聯席 = Associate
董事 = Director
A " Director " has all legal liabilities of a company director. You can find his name in the relevant Company's File in the Company registry ( HK Government Dept. ).
An "Associate Director " is only a :Title". He has no legal liability of the company. He cannot sign any legal document in the role as Director of the company.
In another word, "Associate Director" is a title for a senior staff, who ranking in the company is only next to a director. However, he has nothing to do with 董事 in a legal sense.
Hope I have made my explanation understandable