A two-stage cascade polymerization process for the production of multimodal polyethylene film resins with improved bubble stability is provided. The process comprises polymerizing ethylene or a mixture of ethylene and a C4-8 α-olefin in two reactors arranged in series using a mixed single-site catalyst comprised of a bridged and a non-bridged indenoindolyl transition metal complex to form a multimodal polyethylene resin comprised of a lower molecular weight, higher density component and a higher molecular weight, lower density component.