This invention relates to new multi-component catalyst systems for the polycondensation of polyesters. More particularly, this invention pertains to novel multi-component, germanium based catalyst systems for the polycondensation of PET (polyethylene terephthalate) used in the manufacture of bottles, fibre or film. A multi-component catalyst system for the polycondensation of a polyester comprising the element germanium and one or more catalyst enhancers selected from the group of elements consisting of aluminium, silicon, molybdenum, manganese, lithium and combinations thereof, said elements being in the form of compounds, acids, bases, salts, compositions, oxides or organic complexes.