a polyethylene composition , in particular suitable for the preparation of films , and a process for preparing the same are described . the polyethylene composition of the invention comprises from 50 to 89 % by weight of a first polyethylene component comprising at least one multimodal polyethylene including a plurality of ethylene polymer fractions having distinct molecular weights and comonomer contents , at least one of said plurality of ethylene polymer fractions being prepared by the use of a single site catalyst , and from 50 to 11 % by weight of a second polyethylene component comprising a low or medium density polyethylene .