Four banks slipped from the ranks of 'AA', while the only 'AAA' rated bank in the world also suffered a demotion in a round of revised credit ratings for the banks published yesterday by Standard & Poor's.The new ratings apply to 37 banks from Europe, the United States, Japan and China.Further reviews of S&P's credit ratings are due within two weeks, including those that apply to banks in Australia and New Zealand.Early last month S&P released its revised criteria for rating banks, its Banking Industry Country Risk Assessments. The country assessments serve as an anchor for individual bank credit ratings.With the new criteria in place, S&P eliminated the last remaining AAA bank, shifting Rabobank Nederland to AA from AAA. The AAA rating of Rabobank had been under review in any event for the past two years.BBVA, BNY Mellon, HSBC and Wells Fargo fell from AA- to A+.BNP Paribas, Nordea (of Sweden) and Santander all retained their AA- ratings.Large banks in Japan, Germany and France all retained their credit ratings (whether in the double A or single A range), whereas the US and British banks all saw their ratings fall by one notch (in most cases from A+ to A or from A to A-).Among those cut by one notch were Barclays, Bank of America, Goldman Sachs, JP Morgan, Lloyds Banking Group, Morgan Stanley and Royal Bank of Scotland.Industrial and Commercial Bank of China (the world's largest bank) maintained its A rating. Bank of China, the only other Chinese bank in this first review, fell to A- from A.