There seems to be no word in Korean with the same meaning and used in the same wide contexts as "company". "keep someone company" is expressed as 같이 있다 [있어 주다/드리다], and "company" in the sense of accompanying people is 일행 or 동행. For example, - Do you want some company = 누가 같이 있어 주길 원하세요? [or 주길 원해? in plain style]. - Do you want me to keep you company? = 제가 같이 있어 드릴까요? [ 내가 같이 있어 줄까?]. - Do you have company? (like at a restaurant) = 일행이 있으세요? - He seems to be in the company of shady people = 그는 수상한 사람들과 같이 있는 것 같다.