A government-appointed committee said in January that Sweden needed a new super-watchdog for the sector whose assets, at four times the size of economic output, make it one of the biggest in Europe.
"The Riksbank has ... a good capability to shoulder the responsibility for macro-oversight and should therefore take sole responsibility in Sweden," the central bank said in a statement.
The committee had said the central bank should share responsibility with bank regulator the Financial Supervisory Authority and be advised by two independent experts.
The central bank said it would be hard for such a structure to take effective decisions and that any new organisation should be within the central bank with clear decision-making powers.
The FSA has already said it should have the leading role.
Sweden got off lightly in the 2008 global crisis: no banks went bust and the government did not need to directly inject capital into any lenders. But the central bank has been worried that the bank sector is vulnerable to a new crisis, particularly from the Swedish mortgage market.
(Reporting by Simon Johnson; Editing by Ruth Pitchford)