Abstract: Process for fixed-bed reforming of a hydrocarbon-based feedstock comprising n-paraffinic, naphthenic and aromatic hydrocarbons, at a temperature of between 400 and 700° C., a pressure of between 0.1 and 4 MPa, and a mass flow of feedstock treated per unit mass of catalyst and per hour of between 0.1 and 10 h?1, by bringing said feedstock into contact with a catalyst comprising platinum, a promoter metal selected from the group consisting of rhenium and iridium, a halogen selected from the group consisting of fluorine, chlorine, bromine and iodine, and a porous alumina support in the form of an extrudate characterized by a length “l” of between 1 and 10 mm, a section comprising four lobes, the largest diameter “D” of the cross section of said extrudate being between 1 and 3 mm.