From E. C. Talbot-Booth, Merchant Ships 1949-1950 (New York: McGraw Hill and London: Sampson Low, 1949):
Rio de Janeiro - Service to most Brazilian ports plus the United States and Europe. Managed by Pereira Carneiro. Steamship owners since 1907, controlled by Cia Carbonífera Rio Grandense. The flag was blue with a white diagonal stripe, upper hoist to lower fly, inscribed in red letters CCN.