One senior banker said: "This is yet another example of the ratings agencies pandering to the populist mood rather than giving markets and investors anything which is informed, useful or timely."
Moody's assault on the banks came two days after it slashed sovereign ratings on European nations, including putting Britain's AAA credit rating on negative outlook.
The agency blamed "disrupted markets and a deteriorating, uncertain economic outlook" for its bank review. Moody's added that investment banks in particular were facing headwinds such as "more fragile funding conditions, wider credit spreads, increased regulatory burdens and more difficult operating conditions", which would diminish long-term profits and growth.
Morgan Stanley of the US and two Swiss banks, UBS and Credit Suisse, could be knocked three notches lower on Moody's creditworthiness scale. Goldman Sachs could be downgraded by two notches.
Moody's managing director of European banks, Johannes Wassenberg, denied that the agency was part of the problem, saying it was providing "transparency" to the market.
- Independent