  A three band model containing the essential physics of transition metal
oxides with partially filled t_2g shells is solved in the single-site dynamical
mean field approximation, using the full rotationally invariant Slater-Kanamori
interactions. We compute the metal-Mott insulator phase diagram in the space of
chemical potential and interaction strength, determine the response of the
different phases to perturbations which break the orbital symmetry, and
establish the regimes in which an orbital selective Mott phase occurs. The
results are compared to data on titanates, ruthenates, vanadates and C_60.
