The novel half-metallocene zirconium (IV) bearing quinoline-amino-phenolate tridentate ligand (Zrl) was synthesized and characterized by elemental analysis, NMR spectroscopy, and X-ray crystallography. The complex Zrl, upon activation with MAO, proved active in the polymerization of ethylene (26-2015 kg of PE/mol[Zr].h(-1)), yielding high-density polyethylenes with molecular weight varying from 129 to 364 x 10(3) g.mol(-1). Complex Zrl was also tested in the copolymerization of ethylene with 1-hexene affording high molecular weight poly(ethylene-co-l-hexene) with low comonomer incorporation (1.0-1.9%).