Mr Dries had held talks with both Pro Genk and the Flemish nationalists whose figurehead in Genk is the Federal Secretary of State responsible for asylum and migration Zuhal Demir.
The decision to enter into a coalition with Pro Genk rather than N-VA was taken at a meeting of the local branch of the Christian democrat party on Monday evening.
The decision means that the current coalition will continue for another 6 years. As well as the post of Mayor, the Christian democrats will have 6 Aldermen in the new city cabinet and will also be able to appoint the chair of the local council.
Pro Genk will get two Aldermen.