[en] Nowadays the electronic properties of the rare earth (4f) compounds are clearly better understood than those of the uranium based materials, mainly due to the fact that the 4f states are confined deeply in core of the lanthanide ion and can be treated in most cases as localized. On the contrary the more extended 5f wave functions can participate to the band formation according to the importance of the U-U spacing in the compounds. It will be shown by choosing particular examples in the MT₂X₂ families (M = rare earth or uranium, T = 3d, 4d, 5d transition elements and X = Si or Ge) that Ce and U compounds exhibit certain similarities. One will stress on the influence of the strength of the hybridization of the f states with the valence band states on the electrical and magnetic properties of the ternary compounds which can span all the relevant metallic behaviors including Pauli paramagnetism, mixed valence, spin fluctuation, Kondo state, heavy fermion, local moment magnetism and transition from magnetic ordering to either heavy fermion or mixed valence state