BNP Paribas expects a higher capital impact and lower return on investment than initially projected for its acquisition of AXA Investment Managers, after the European Central Bank clarified its regulatory stance on such deals.

The French bank last year agreed to buy the asset management arm of French insurer AXA for 5.1 billion euros ($5.79 billion) through its insurance arm BNP Paribas Cardif in a move that would create a European asset-management giant and bulk up its investment-management operations.