Standard & Poor's reduced its credit ratings on several big banks in the United States and Europe on Tuesday as the result of an overhaul of its ratings criteria.

Banks, including JPMorgan Chase & Co , Bank of America Corp , Citigroup Inc , Wells Fargo & Co , Goldman Sachs Group Inc , Morgan Stanley , Barclays Plc , HSBC Holdings Plc , and UBS AG , had their ratings reduced by one notch each. A notch is one third of a letter rating.

(Reporting by David Henry; editing by Andre Grenon)