Method and system for interconnecting electronic marketplaces

Agreement information created between a participant and another participant of the same or another electronic marketplace center is held in an agreement DB. On the basis of the agreement information, interconnection processing between electronic marketplaces is controlled such that a service system can transfer business data to another service system of another electronic marketplace center, the service system requests business processing to the another service system of the another electronic marketplace center, respond to a request from the another service system of the another electronic marketplace center, or the service system can be provided to the another electronic marketplace center.