Process for the removal of higher hydrocarbons contained in natural gas further containing sulphur compounds by simultaneous conversion of the hydrocarbons to aromatic compounds and methane in presence of a catalyst comprising a crystalline alumino silicate having in its anhydrous state a formula expressed in terms of mole ratios as follows: xQ:0.01 0.1 M.sub.2/nO:0 0.08 Z.sub.2O.sub.3:SiO.sub.2:0.0001 0.5 Me, wherein: Q is an organic nitrogen compound; Z is aluminum, boron, gallium or mixtures thereof; x is between 0 and 0.5; M is at least one metal cation of valence n or proton; and Me is at least one of the metals, which form a water insoluble sulphide by contact with a sulphur compound being present in the natural gas and/or in a preparation mixture for preparation of the catalyst.