A series of novel titanium(IV) complexes with S-bridged biphenol such as 5-tert-butyl-4-hydroxy-2-methyl phenyl sulfide (BHMPS) have been synthesized. These catalytic precursors formulated as [R3Ti (O boolean AND O) TiR3](n) were found to be highly active in polymerization of ethylene at high temperatures and pressures in combination with ethyl aluminium sesquichloride (Et3Al2Cl3) as co-catalyst. The polyethylene yields range from 250-1600 Kg PE/mmole catalyst. The GPC of polymers typically correspond to ultra low molecular weight polyethylene with narrow polydispersities.