This pdf is an interesting piece of work of the International Competition Network (ICN) with an overview of arguments why regulation of banks occurs and what the role of the competition authorities should be. A tiny bit outsiders perspective, as one tends to see more often when non-industry supervisors take a bite in the banking cake, but generally quite good.
The ICN is a supranational coordination body, exclusively for competition regulators. What the BIS is to central banks, the ICN is to competition authorities. ICN started in 2002.