This paper presents a new approach for Business Process Integration based on Interaction Protocols. It enables both integration and collaboration of autonomous and distributed business processes modules. We present a semantic formalisation of the interaction protocols notations used in our approach. The semantics and its application are described on the basis of translation rules to Coloured Petri Nets and the benefits of formalisation are shown. The verified and validated interaction protocols specification is exploited afterwards with an intermediate agent called « Integrator Agent » to enact the integration process and to manage it efficiently in all steps of composition and monitoring.