So basically, if I were to say something like 'That guy working on behalf of organization x, has said that he would relay information within 3 working days', what would be a word or term for 'that guy working in/for organization x'?
At first I thought the term 'party' would be appropriate, but when looking up it's definition, it's defined only for political parties (and frat boy parties xD). Furthermore, there seems to be many terms to describe those working in the same organization as one's own, the most formal I can think of being colleague, but none that seem to describe those working as part of another organization that one's own organization is collaborating with.