The present invention relates to a method for producing an aqueous suspension concentrate formulation and novel suspension concentrate formulations of the compound of formula I.The method comprises: a) providing an aqueous slurry of coarse particles of the compound of the formula I, where the compound of the formula I is at least partially present in its crystalline form B, which, in an X-ray powder diffractogram at 25° C. and Cu-Kα radiation, shows at least three, preferably at least four, in particular at least 5 or at least 7 or at least 9 or all of the following reflexes, given as 2θ values: 8.0±0.2°, 9.5±0.2°, 10.7±0.2°, 11.0±0.2°, 11.2±0.2°, 11.7±0.2°, 14.2±0.2°, 15.6±0.2°, 16.5±0.2°, 17.7±0.2°, 21.5±0.2°;b) comminuting the coarse particles in the slurry of the compound of formula I, which is at least partially present in its form B, in the presence of the at least one surfactant.