I would try registering a component implementing javax.transaction.Synchronization with org.jboss.seam.transaction.Transaction.instance().registerSynchronization()
You have to figure out the life cycle of this component. Maybe an event scoped component that register itself at @Create time.
You also need <transaction:ejb-transaction/> in components.xml for the callback method to be invoked.
However, note that such event get raised only by the Seam Application Framework, that is the EntityHome or HibernateEntityHome classes.
Thanks for the response. This solution worked for me.
I just added action for seam event in component.xml.