  We discuss orientational order in two dimensions in the context of systems
with competing isotropic interactions at different scales. We consider an
extension of the Brazovskii model for stripe phases including explicitly
quartic terms with nematic symmetry in the energy. We show that leading
fluctuations of the mean field nematic solution drive the isotropic-nematic
transition into the Kosterlitz-Thouless universality class, i.e. these systems
have a thermodynamic phase with orientational quasi-long-range order.
