MUFG Bank, Ltd. (株式会社三菱UFJ銀行, Kabushiki Gaisha Mitsubishi Yūefujē Ginkō) is the largest bank in Japan. It was established on January 1, 2006, following the merger of the Bank of Tokyo-Mitsubishi, Ltd. and UFJ Bank Ltd. MUFG is one of the three so-called Japanese "megabanks" (along with SMBC and Mizuho). The bank serves as the core retail, corporate, and investment banking arm of the Mitsubishi UFJ Financial Group. Its traditional client base is made up of Japanese corporates, but overseas corporate lending increased 35% in the nine months to December 31, 2011. The bank has steadily increased its tier 1 capital ratios from 7.76% in 2009 to 13.04% as reported in February 2012, and its credit ratings have been unaffected by developments in Europe. Standard & Poor's assigned BTMU's most recent series of senior unsecured bonds an A-plus rating (as at February 2012). As of June 23, 2019, Mitsubishi UFJ Financial Group / MUFG Bank was ranked by as the largest bank in Japan and the fourth largest in the world. The bank's head office is in Marunouchi, Chiyoda, Tokyo, and it has 772 other offices in Japan and 76 offices overseas.