User-centric services bring additional constraints to the problem of automated service composition. While in business-centric settings the services are orchestrated in order to accomplish a specific business task, user-centric service composition should allow the user to decide and control which tasks are executed and how. This requires the ability not only to automatically compose different, often unrelated, services on the fly, but also to generate a flexible interaction protocol that allows the user to control and coordinate composition execution. In this paper we present a novel automated composition approach that aims to support user-centric service provisioning. Specifically, we associate the service to so-called service objects and provide a declarative notation to express composition requirements in terms of the evolution of those objects. On top of these objects we also define the user control activities and constraints. Using the automated planning techniques, our approach generates a service composition that orchestrates services in a way it is requested by the user.