Dexia bank Dexia group, the world's largest city bank, was formed by the merger of Luxembourg international bank, French public bank and Belgian Credit Cooperation Bank in 1996. It is a multinational group with strong financial resources and is listed on the Paris Stock Exchange, Brussels Stock Exchange and Luxembourg stock exchange. Dexia bank's long-term debt is obtained by standard & Poor's "AA" and Moody's investment "aa2" credit rating.