Josef Ackermann, Deutsche Bank AG chief executive, said regulations that safeguard financial stability should be globalized, according to Thomson Financial News.

'The nationalistic approach (to regulation) is just too narrow ... the crisis has clearly revealed, not caused, this fundamental flaw,' he said, referring to the drought in credit markets sparked by bad mortgage debts in the U.S.

Speaking at a conference here on financial market regulation hosted by the London School of Economics and Deutsche Bank, Ackermann also acknowledged the importance of transparency to restore confidence in markets -- but he said there must be limits. 'The question is how far you will go ... so much is now in the open and it's not always in the interests of shareholders,' he said.

Meanwhile, accounting standards and practices should also be harmonized for complex financial instruments, Ackermann said. The differences between U.S. GAAP and IFRS regulations are significant, he added.

Ackermann also said a move away from fair-value accounting 'right now', as has been suggested in some quarters, would be damaging because investors would fear banks had something to hide.