Fitch international rating agency downgraded Swiss bank UBS AG over lower government support and put seven large U.S. and European banks on credit watch negative, the agency said on Friday.
The agency cited exposure to the European debt crisis and concern about the business model of purely investment banks for the move.
UBS's long-term issuer default rating fell to A from A+, the agency said in a statement.
Fitch also put on review for potential downgrade to ratings for Barclays Bank Plc, BNP Paribas, Credit Suisse Group AG, Deutsche Bank AG, Societe Generale, Bank of America Corp, Morgan Stanley and Goldman Sachs Group Inc.
The cuts may in most cases be one notch and in some cases two notches, the agency said.