Treatment of the mixed amidinate-amido-lithium, [PhN(CH₂)₃NC(Ph)NSiMe₃]₂Li₄·2Et₂O, with group IV metal chlorides yields the corresponding compounds 3–5. Their structures were confirmed by X-ray diffraction analysis, showing a distorted octahedral geometry. The catalytic behaviors of compounds 3–5 were investigated in the presence of MAO as a co-catalyst. Compounds 3 and 4 showed high activities for ethylene polymerization.