The "Belief Models" framework is a very general formal theory of rational belief. It encompasses propositional logic belief sets, but also ranking functions and lower previsions (i.e. lower probabilities). de Cooman (2005) shows that AGM-style expansion and revision operators can be defined in this framework. In this paper I show that "merging operators" -- a kind of general theory of aggregation -- in the style of Konieczny and Pino-Perez (2002) can also be generalised from propositional logic to Belief Models. I will focus on the consequences for aggregating probabilities and lower probabilities.