A copolymer with high chemical homogeneity, consisting of (A) 50 to 30% by weight of ethylene, (B) 50 to 70% by weight of C4- to C24-hydrocarbyl ester of (meth)acrylic acid, (C) 0 to 5% by weight of (meth)acrylic acid and (D) 0 to 10% by weight of copolymerizable monomers, obtainable by polymerizing a mixture of 80 to 60% by weight of ethylene, 20 to 40% by weight of (meth)acrylic acid and 0 to 10% by weight of copolymerizable monomers in a backmixing, continuous polymerization apparatus, and subsequently polymer-analogously esterifying the resulting copolymer with C4- to C24-hydrocarbinols. The inventive copolymer is suitable for improving the cold flow properties of fuel oils, for lowering the lower mixing temperature of cold flow improver additives into fuel oils, and for improving the filterability of fuel oils comprising cold flow improver additives.