6. Ecobank Nigeria (₦1.5 trillion)

Established in 1986, Ecobank is a commercial bank. It is a subsidiary of Ecobank Transnational Inc., a leading pan-African banking group with more than 1,150 branches all over Africa. As of December 2011, Ecobank Nigeria controlled total assets valued over N1.5 trillion making it one of the five largest banks in Nigeria.