Royal Bank of Scotland, Barclays and HSBC were the three UK banks among the downgrades, which ranged from one to three notches.
Credit Suisse was the only bank in the group to suffer a three-notch downgrade. Barclays, BNP Paribas, Royal Bank of Canada, Citigroup, Goldman Sachs Group, JPMorgan Chase, Credit Agricole, Morgan Stanley, UBS and Deutsche Bank all had their ratings cut by two notches.
HSBC, Bank of America, Royal Bank of Scotland, and Societe Generale were also cut by one notch.
Lloyds has also seen its credit rating cut in a separate announcement as the bulk of its financial operations are UK based.
Moody’s global banking managing director Greg Bauer says: “All of the banks affected by today’s actions have significant exposure to the volatility and risk of outsized losses inherent to capital markets activities.”
Last month, Moody’s downgraded Santander UK and 16 Spanish banks due to concerns about the banks’ credit-worthiness and the Spanish government’s ability to provide support.
In February, Moody’s warned it may cut the credit ratings of 17 banks and financial services companies, including Barclays and HSBC, due to difficult market conditions.