Banks and investment banks whose health is crucial to the global financial system should operate under a unified regulatory framework with "appropriate requirements for capital and liquidity", according to Tim Geithner, president of the Federal Reserve Bank of New York.

Writing in today's Financial Times, Mr Geithner, a key US policymaker throughout the credit crisis and one of the main architects of the rescue of Bear Stearns, says the US Federal Reserve should play a "central role" in the new framework, working closely with supervisors in the US and around the world.