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owner of a company; head of a company
社主が息子に会社を譲った。
The company head handed over the business to his son.
新聞の社主は新しい方針を表明した。
The newspaper's owner announced a new policy.
社員たちは新しい社主の方針を不安げに待っている。
The employees are anxiously awaiting the new company owner's policy.