TiCl4 immobilization on different compositions of mixed support of MgCl2 center dot A xEB and poly(methyl acrylate-co-1-octene) (PMO; synthesized through ARGET ATRP) resulted in the formation of solid catalysts having variation in incorporation of titanium. The effect of mixed support composition onto the titanium immobilization, catalyst morphology and performance for ethylene polymerizations has been evaluated. The polyethylenes synthesized showed broad to bimodal MWD in GPC and DSC where the broadness was found to be dependent upon the ratio of mixed support MgCl2 center dot A xEB/PMO. The morphological features of PE as elucidated using SEM lead to postulation of polymer formation mechanism.