Metadata portals offer access to Open Data, which is increasingly published on the basis of RDF vocabularies and ontologies. Individual datasets include URIs and descriptions of licenses under which the datasets are published. Licenses can be defined by attributes of the types permission, requirement and prohibition. This paper focuses on the problem of relicensing datasets that include multiple other open datasets published under different licenses. If combined datasets are republished, a chosen license must comply with the original licenses of each dataset. The approach is based on mapping licenses to deontic interpretations and combining them using an OR-composite operator. The result of the operator is used to determine matching licenses from a Knowledge Base containing license information. The approach is evaluated based on the Creative Commons License Compatibility Chart.