A process for the preparation of ethylene polymers comprising polymerizing ethylene, optionally with one or more ±-olefin comonomers, in the presence of: (i) a solid catalyst component comprising titanium, magnesium, halogen and optionally an internal electron-donor compound, (ii) an aluminum alkyl compound, and (iii) an antistatic compound selected among the hydroxyesters with at least two free hydroxyl groups, wherein the weight ratio of aluminum alkyl compound to solid catalyst component is higher than 0.80 and the weight ratio of antistatic compound to aluminum alkyl compound is higher than 0.10.