rating agency       
noun [ C ]  finance & economics uk/ˈreɪ.tɪŋ ˌeɪ.dʒən.si/ us/ˈreɪ.t̬ɪŋ ˌeɪ.dʒən.si/ (also ratings agency, credit rating agency, credit ratings agency)
 (还贷信用)评级机构
an organization that gives ratings (= scores) to people, companies, or countries according to how safe it is to lend money to them
  Rating agencies are important players in the financial markets. 评级机构是金融市场的重要角色。