This paper reports a Monte Carlo (MC) study of the ordering in a semiflexible liquid crystal model designed to give a crude representation of 4-n-octyl-4’-cyanobiphenyl (PCB). A mechanically stable nematic phase is obtained and the question of its thermodynamic stability is addressed by comparing the free energy to that of the isotropic phase. The free energies are calculated by thermodynamic integration using an efficient configuration biased MC scheme. Pair distribution functions, orientational correlation functions, and conformational properties of the nematic and isotropic phases are contrasted. In the isotropic phase the equation of state is compared with theoretical predictions for systems of convex molecules and chains made up of tangent hard spheres.