The Chiba Bank, Ltd. (株式会社千葉銀行, Kabushiki-gaisha Chiba Ginkō) (TYO: 8331) is the biggest bank in Chiba Prefecture, Japan. Listed on the Nikkei 225, it has branches in Osaka, New York City, London, and Hong Kong. Assets — $106.1 billion (2015). Chiba bank was established in March 1943. In June 1998, Standard & Poor's downgraded Chiba Bank' s credit rating from A-minus to BBB-plus because of negative long-term ratings.