A catalyst that comprises at least one binder and at least one crystallized material with hierarchized and organized porosity in the fields of microporosity and mesoporosity is described, whereby said crystallized material consists of at least two elementary spherical particles, each of said particles comprising a mesostructured silicon-oxide-based matrix that has a mesopore diameter of between 1.5 and 30 nm and that has microporous and crystallized walls with a thickness of between 1 and 60 nm, whereby said elementary spherical particles have a maximum diameter of 200 microns. Said catalyst is used in a process for oligomerization of an olefinic feedstock that contains hydrocarbon molecules that have 2 to 12 carbon atoms per molecule.