A series of new cobalt and nickel complexes LMX2 (M=Co, X=Cl; M=Ni, X=Br) bearing 2, 6-bis(imino)phenoxy ligands were synthesized. The solid-state structures of 1 and 4 have been determined by single-crystal X-ray diffraction study. Treatment of the complexes LMX2 with methylaluminoxane (MAO) leads to active catalysts for oligomerization of ethylene with catalytic activities in the range of 1.2×105–2.1×105 g mol−1 h−1 atm−1 for Ni complexes, and ∼103 g mol−1 h−1 atm−1 for Co complexes. The oligomers were olefins from C4 to C16.