This paper illustrates a typical pathway towards increasing electronic interaction with external business partners. Based on the case study of ETA SA, a Swiss manufacturer of watch movements and components, it explores current issues in portal-based B2B integration. In order to allow for tighter process integration with distinct customers, ETA conceives a multi-channel architecture which provides electronic services to customers using either direct or portal-based electronic channels. Since a multi-channel approach typically is associated with major integration challenges, the paper outlines and discusses the vision of service-oriented architecture for interorganizational integration.