The present invention relates to a process for preparing a solid catalyst component suitable for producing polyethylene and its copolymers, said process comprising the steps of: (a) contacting a dehydrated support having hydroxyl groups with a magnesium compound having the general formula MgR1R2; (b) contacting the product obtained in step (a) with modifying compounds (A) and/or (B) and/or (C), wherein: (A) is at least one oxygen and/or nitrogen comprising organic compound; (B) is a compound having the general formula R11f(R12O)gSiXh, (C) is a compound having the general formula (R13O)4M, and (c) contacting the product obtained in step (b) with a titanium halide compound having the general formula TiX4, wherein Ti is a titanium atom and X is a halide atom, wherein an organometallic compound is added either before step (a) and/or after step (c). The invention also relates to a solid catalyst component obtainable by said process. The invention further relates to a process for producing polyethylene and its copolymers in the presence of the solid catalyst component and a co-catalyst.