The Internet has the inherent potential of enabling a global marketplace. However, so far electronic shopping systems have had relatively limited success in supplanting or augmenting traditional physical and catalog shopping. The biggest impediment at the stage of product identification is the necessity to manually evaluate and integrate product information. This issue can be alleviated by modeling product information on a semantic level, which enables vocabularies of heterogeneous electronic product catalogs to be integrated. Adopting a mediator architecture for the construction of distributed federated product catalogs preserves each participating vendor's autonomy. Besides creating added value for customers this enables a variety of new business models for emerging intermediaries