With the outbreak of World War I and the participation of the Ottoman Empire in the war, the Bank's officials of British and French nationality fell in the position of citizens of hostile countries. The Ottomans threatened the Bank with confiscation, and the general manager and his deputy had to leave their posts and the country until the end of the war. The administration was taken over by non-Muslim Ottomans. Berç Keresteciyan was among them. He was deputy general manager and later became general manager of the Bank.