Challenges facing central banks included "how to ensure that banks' liquidity insurance remains appropriate as technological change increases the risk of larger and faster deposit runs, of the kind seen this spring in the U.S.," the BoE's executive director for markets, Andrew Hauser, said.

The sudden collapse of U.S. lender Silicon Valley Bank in March caught regulators by surprise as depositors rushed to empty their accounts using online banking services.

In a speech made at a conference organised by King's College London, Hauser said central banks also needed to judge where their balance sheets should settle after expanding hugely since over 15 years of emergency bond-buying.

A third challenge was how to ensure the stability of the financial system as a whole - including non-bank market finance such as hedge funds - in the face of increasingly frequency systemic liquidity shocks.

(Reporting by David Milliken; Writing by William Schomberg)