Enterprise application integration (EAI) is one of the most current topics in information technology today. Applying Service Oriented Architecture (SOA) is a fair headway in EAI, but involving the productive enterprise systems (ES) into such integration scenarios still raises a lot of open issues: the data representation probably differs in participating ESs, which indicates the need for detection of semantically related concepts between them, the appropriate services of the SOA architecture must be found to the right place of the chain of the collaborative business process and the composed process containing semantic services must be prepared for the process run-time, etc. In this paper we present an approach which extends SOA standards by attaching semantic metainformation to the services of ESs. The main part of our work is the adaptation of the services from legacy systems into our semantically enriched SOA environment. The focus is set on automatic finding of semantic related pairs between global schema concepts and the concepts of services. Furthermore a method for generation of transformation rules between the service's data schema and our semantic global schema is also introduced.