Abstract: The present invention relates to a process to control the molecular weight distribution of polyethylene and to reduce the smoke quantity during the formation of polyethylene, wherein the process for preparing polyethylene having narrow molecular weight distribution, comprising the following steps: a) continuously polymerizing ethylene by subjecting ethylene stream, hydrogen, solvent, Ziegler-Natta catalyst comprising titanium, co-catalyst, external electron donor selected from alkoxysilane compound into the reactor to produce polymer slurry; b) removing residue reaction gas from the polymer slurry stream obtained from a) and c) separating polymer stream in b) from the solvent.