The service metaphor naturally fosters integration and interoperability among distributed applications. In an open system environment, however, real integration among heterogeneous software components is a challenging issue. This paper describes an approach to interoperability between Jini services and Web Services. The approach relies on the use of automatically-generated services named bridges which transparently smooth out the technological gap existing between Jini services and Web Services. Generation and management of bridges is concretely achieved by exploiting functionalities of a service architecture named GOAL. GOAL (General brOkering Architecture Layer) aims at simplifying the development and the management of highly flexible and scalable applications based on Jini services. It offers a design pattern which decouples the design of service functionalities from distribution concerns like security, remote communications, management of partial failures and so forth. The proposed approach is demonstrated through the realization of a system for on-line auctions over the Internet.