External business processes (choreography models) are currently disconnected from internal processes (workflow models), which leads to synchronisation and verification problems. Connecting these by directly mapping internal to external processes requires a quadratic amount of mappings; an intermediate ontology reduces the amount of necessary mappings but is not trivial to construct due to the variety in workflow meta-models. We introduce our multi meta-model process ontology ( m3po), which is based on various existing reference models and languages from the workflow and choreography domain. The m3po ontology relates workflow models to choreography models and allows choreography extraction from internal workflow models. An initial validation is given by translating an IBM Websphere MQ Workflow model into the m3po ontology and subsequently extracting an Abstract BPEL model from the ontology.