Silane-modified oxidic or siliceous filler with a bead fraction below 75 .mu.m of less than 15 wt. % and a median particle size distribution between of 150 to 500 .mu.m, which is produced by the reaction of at least one microbeaded or microgranular, oxidic or siliceous filler in a compressed gas with at least one silane. The silane-modified oxidic or siliceous fillers are used in rubber compounds.