Can Merck sign a tripartite contract?

Of course. According to the relevant information of Merck, Merck can sign a tripartite contract. Third-party contract refers to that after employees enter an enterprise, they do not sign a labor contract with the enterprise, but sign a labor contract with the human resources company outsourced by the enterprise (that is, the third party). Therefore, employees working in enterprises are dispatched, not formal employees of enterprises.