The field of variability management deals with the formalization of mandatory, alternative and optional domain concepts in product line engineering. Ontologies in turn, describe domain knowledge in form of predicates, subjects and constraints in various forms. Based on existing ontology mapping approaches, we developed a method to organize a set of modular ontologies using the concepts of variability management (MOVO). This ontology driven variability model can be stepwise adapted to the needs of a business driven one, resulting in a variability model that fits the needs of business and makes modular ontologies reusable in a simple manner. In order to avoid a technological break and to benefit from the opportunities that ontologies offer, the resulting variability model is expressed in an ontology itself. The approach is evaluated by one case study with enterprise architecture ontologies.