This paper explores market interaction by oligopolists who may choose different action spaces. It discusses a question of the possibility of equilibrium in oligopoly where some firms control prices and others quantities. More specifically, we consider a two-stage game in which three firms first decide simultaneously whether they take as a control variable price or quantity, and afterwards compete contingent on the chosen types of control variables. By adopting a numerical approach, we show that such mixed oligopolies may emerge as an equilibrium in the two-stage game, depending on the degree of substitutability and complementarity between goods.