company man

A male worker more loyal to management than to his fellow workers; also, one who informs on fellow employees. For example, He'll never join in a strike; he's a company man. Dating from the 1920s, a period of considerable labor unrest, this term uses company in the sense of "a business concern" and was often applied as a criticism by supporters of labor unions.

The noun has one meaning:

Meaning #1: an employee whose first loyalty is to the company rather than to fellow workers