Standard & Poor's will begin to release its updated credit ratings for banks from late November, following publication yesterday of its revised criteria for rating banks.S&P will release revised ratings on the 30 largest global banks first.  Subsequent bank ratings will be released in more regionally focused groups, with nearly all rating actions being finalised by mid-December. There is no exact release date available yet on revised ratings for banks in Australia and New Zealand.Yesterday, S&P published its latest Banking Industry Country Risk Assessments (BICRAs) for 86 countries, using updated criteria.As expected, and in line with an earlier draft, S&P cut the country rating for both Australia and New Zealand by one notch. Under the BICRA rating, S&P now scores Australia in group two and New Zealand in group three.Canada and Switzerland are the only two countries in group one. Chile, Denmark, South Korea, the United Kingdom and the United States all made group three, as did the market pariah of the moment, Italy.The country assessments serve as an anchor for individual bank credit ratings, which can be notched up or down, and take into account S&P's relative strength ratings of a bank's business position, capital and earnings, risk position and liquidity.Australian banks may be trusting that the improving profile of their liabilities (less wholesale debt, more longer term debt, rising deposits and an abundance of liquid assets) will help maintain their AA ratings from S&P. However, this may not flow through to the Australian banks' New Zealand subsidiaries.