Requirements engineering is a key activity on any software development project. In Software Product Line development, this activity is even more important since requirements may encompass commonality and variability. Furthermore, a requirement specification usually is composed by more than one model. In this context it is necessary to specify the requirements variability in the different models of a Software Product Line requirements specification. In order to solve this issue, this paper proposes a multimodel approach for specifying the requirements for the products of a Software Product Line. This multimodel is used in a model-driven development process in order to obtain the requirements of a single product by applying model transformations. This solution increases the flexibility allowing developers to add more views depending on the domain and to obtain the product requirements by using model-transformations, whereas improves the productivity. The feasibility of the approach is illustrated through a running example.