A process for the preparation of a catalyst comprising at least one support, optionally at least one metal from group VIII of the periodic classification of the elements and at least tungsten, said process being characterized in that the tungsten is introduced onto the support, in an organic solvent A, in the form of at least one mononuclear precursor compound based on W, in its monomeric or dimeric form, having at least one W═O or W—OR bond or at least one W═S or W—SR bond where [R═CxHy where x≧1 and (x−1)≦y≦(2x+1) or R═Si(OR′)3 or R═Si(R′)3 where R′═Cx′Hy′ where x′≧1 and (x′−1)≦y′≦(2x′+1)].