An ethylene oligomerization catalyst that oligmerizes ethylene to a series of α-olefins and that has a Schulz-Flory constant of about 0.75 to 0.995 produces a stream of α-olefins. This stream is then added to a vessel containing ethylene and a copolymerization catalyst that copolymerizes ethylene and α-olefins. The resulting branched polyethylene often has good processing properties. The good processing is presumably due to the presence of “long chain branching”. Such polymers are useful for films and other packaging materials, and for molding resins for molding parts such as industrial, automotive or electrical parts.