We investigate both quantity and price competition in two differentiated oligopolistic frameworks in which firms are heterogeneous with respect to the ownership structure, i.e. managerial firms compete against entrepreneurial firms, or to the timing decisions, i.e. leaders compete against followers. We show the circumstances under which delegation and sequential strategies, shown to be equivalent under unilateral delegation (Vickers, The Economic Journal, Vol. 95 (1985), pp. 138–147), enable firms to out-perform their rivals and create scope for welfare gains. The different effects of changes in market structure and the degree of product substitutability on firms' profitability and social welfare are discussed.