Green’s Dictionary of Slang

(US) someone who identifies with his company and is deferential to the company’s rules and folkways; in union terms, a worker who is seen by his peers as loyal to the employers rather than the union.

1942		B.H. Porter ‘Truck Driver Lingo’ in AS XVII:2 Pt 1 103/1: Company Man. Squealer .
1957		Irving Panken ‘Company Man’ [unpub. lyrics] Oh the company man, the company man, / Look at he, / Earning sixteen-three [W&F].
1969		L. Schecter Jocks 108: Unfortunately it has become too much of a custom to ridicule what is termed ‘the company man’.
2002		R. Sullivan LAbyrinth 203: Perez despised him [and] called him a ‘company man’ .