The invention concerns a new catalyst containing (a) a zeolite carrier, (b) a metal from group VIII and (c) an additional metal selected from tin, germanium and lead, forming an alloy with the metal of group VIII, said additional metal being introduced as organic compound.The catalyst can be used, in particular, in hydrocarbon hydrocracking reactions.The figure of the accompanying drawing illustrates the conversion of n-heptane in the presence of a catalyst containing palladium and tin. Curve (A) illustrates this conversion at different temperatures, curves (B) and (C) giving the results after ageing of the catalyst.