Electronic marketplaces, or e-commerce portals, bring together many online suppliers and buyers. Each individual participant can potentially use his own format to represent the products in his product catalog, and mapping between them becomes non-trivial. Complicated products require knowledge-intensive descriptions, or ontologies, and catalog integration shifts to integration of product ontologies. The industrial experience analyzed in the paper shows that in some cases the marketplaces require syntactic-level integration of product ontologies, in which the integration rules are created and updated (semi)automatically. Ontology integration tools that satisfy these requirements have not yet been developed, and accordingly we sketch a framework for automated ontology integration that is able to fulfill these requirements.