This paper studies the development of institutional structures for prudential and business conduct supervision of financial services over the past decade for 98 high and middle income countries. It identifies possible drivers of changes in these supervisory structures using a panel ordered probit analysis. The results show that (i) countries advancing to a higher stage of economic development tend to integrate their financial sector supervisory structure. Similarly, improvements in overall public governance drive countries to adopting more integrated supervisory arrangements. (ii) Greater independence of the central bank could entail less integration of prudential supervision, but not necessarily of business conduct. (iii) Small open economies opt for more integrated structures of financial sector supervision, especially on the prudential side. (iv) Financial deepening makes countries integrate supervision progressively more, however, greater development of the non-bank financial system including capital markets and the insurance industry makes countries opt for less integrated prudential supervision but not business conduct supervision structures. (v) The lobbying power of concentrated and highly profitable banking sectors acts as a significant negative force against business conduct integration. (vi) Countries with banking sectors that have been more exposed to aggregate liquidity risk, due to their high share of external funding, tend to integrate more their prudential supervision. Finally, (vii) a country that has experienced past financial crises is more likely to integrate its supervisory structure for financial services.