A sweeping overhaul of financial supervision across Europe moved closer on Wednesday when the European Commission unveiled new rules it hoped would prevent a repeat of the worst financial crisis in decades.

“We have had a crisis – and we have to learn from this crisis ... This proposal is a first,” said Joaquín Almunia, economic and monetary affairs commissioner. But the publication of the draft legislation, which would create three pan-European Union authorities to develop and enforce common rules on banking, insurance and securities markets, raised fears that the powers of national supervisors could be eroded.