Abstract. [Context and motivation] Ever-growing systems’ complexity and novel requirements engineering approaches such as reuse or globalization imply that requirements are produced by different stakeholders and written in possibly different languages. [Question/ problem] In this context, checking consistency so that requirements specifications are amenable to formal analysis is a challenge. Current techniques either fail to consider the requirement set as a whole, missing certain inconsistency types or are unable to take heterogeneous (i.e. expressed in different languages) specifications into account. [Principal ideas/ results] We propose to use model composition to address this problem in a staged approach. First, heterogeneous requirements are translated in model fragments which are instances of a common metamodel. Then, these fragments are merged in one unique model. On such a model inconsistencies such as under-specifications can be incrementally detected and formal analy...