Indeed the word is "companero", but its not as formal as comrade which also exists as "camarada", in this context its actually more like partner (in a professio

Indeed the word is "companero", but its not as formal as comrade which also exists as "camarada", in this context its actually more like partner (in a professional sense) but not as informal as brother or pal in english. Peron put that word en vogue around here.