Fortis Holding, the Brussels-based insurance group, is to take a charge of €362.5m ($504m) in its first half results after losing a case in the Netherlands against one of its former subsidiaries.

The listed rump of the former Belgo-Dutch banking and insurance group that was split up last year had sought to argue that it should not be liable for a claim brought by its former subsidiary, Fortis Bank Nederland (FBN), which is now owned by the Dutch state.