Abstract: Polymers of melt index between 1 and 20 dg/min, which comprise units (A) derived from ethylene, units (B) derived from an ethylenically unsaturated .alpha.,.beta.-dicarboxylic acid anhydride and, where appropriate, units (C) derived from an alkyl acrylate or methacrylate in which the alkyl group contains from 1 to 12 carbon atoms, characterized in that, per 100 moles, they comprise: from 83 to 99.7 moles of units (A), from 0.29 to 3 moles of units (B), from 0 to 13.6 moles of units (C) and, furthermore, from 0.01 to 0.4 moles of units (D) derived from at least one polyol polyacrylate or polymethacrylate.Their process of preparation consists of copolymerizing a mixture of ethylene, an anhydride of an ethylenically unsaturated .alpha.,.beta.-dicarboxylic acid, at least one polyol polyacrylate or polymethacrylate and, where appropriate, at least one alkyl acrylate or methacrylate, at a temperature of between 140.degree. and 280.degree. C.