We analyze an interaction between a firm’s choice of organizational structure and competition in the product-market. Two organizational structures are considered, namely a centralized-organization, whereby formal authority is retained by a principal, and a decentralized-organization, whereby formal authority is delegated to an agent. We show that the choice of organizational structure hinges on a trade-off between operating-profit and managerial effort. The principal may prefer to choose an organizational structure that generates lower operating-profit to motivate the agent to work hard. The choice of organizational structure may also determine whether the rival is active in the market or forced to exit the market.