There is provided a process for producing an organopolysiloxane A comprising at least one (meth)acrylate group, said process comprising the following steps: a) the following are reacted at a temperature of between 50 and 140° C., optionally between 70 and 130° C.: at least one organopolysiloxane B comprising at least one epoxy group, with acrylic acid or methacrylic acid or a mixture of the two, in the presence of a catalyst C which is a complex of iron in the oxidation state (III), of formula (1) below: [Fe(L1)3]  (1) in which the symbols L1, which may be identical or different, represent a ligand chosen from the group made up of: a β-dicarbonylato anion or the enolate anion of a β-dicarbonyl compound, a carboxylate anion and an alkoxide anion, and of at least one solvent, and b) the product obtained, which is said organopolysiloxane A or a mixture containing predominantly said organopolysiloxane A, is isolated.