BNP Paribas’ affiliate, BICICI, said on its website that the closure was temporary.
It said that the “judicial and regulatory confusion” over the past few days forced it to close its offices, adding that it was unable to ensure the physical security of its employees.
On Friday the BCEAO warned that banks faced sanctions if they continued to serve members of Gbagbo's regime, including being cut off from the region's clearing system.
The central bank had already cut links with Gbagbo himself, and blocked funding since the international community recognised his rival Alassane Ouattara as the winner of presidential elections in November.
Analysts and diplomats say international sanctions are starting to make Gbagbo struggle to find money to pay civil servants and troops, whose support he depends on.