Several e-business frameworks are developed to definestandards for information sharing within and betweencompanies. These frameworks only standardizestructure of messages and aren’t able to definesemantics. It leads to slow and costly dynamicBusiness-to-Business (B2B) integration. The use ofSemantic Web Service (SWS) technologies has beensuggested to enable more dynamic B2B integration ofheterogeneous systems and partners. We present asemantic B2B mediator based on the WSMX –a SWSexecution environment, to tackle heterogeneities inB2B services. We particularly show how WSMX can bemade to support the RosettaNet e-business frameworkand how it can add dynamics to B2B interactions byautomating mediation of heterogeneous messages. Weused a reasoner in interaction with WSMX forautomatic consistency checking of instances in runtime.The benefits of applying SWS technologiesinclude more flexibility in accepting heterogeneity inB2B integrations and easing back-end integrations.This allows introducing more competition into thepurchasing process within e-business frameworks.