New York: In a major blow to the already- struggling banking sector in a weak global economic scenario, rating agency major S&P has downgraded as many as 15 large banks globally, including some big American names like Bank of America, Citigroup and Goldman Sachs.
Standard and Poor's has also cut ratings for US-based banking giants like JP Morgan, Morgan Stanley, Wells Fargo, while some European banking titans like Barclays, HSBC, Lloyds Banking Group, RBS (Royal Bank of Scotland) and Rabobank have also been downgraded.
In a major rating action review of as many as 37 banks globally, S&P has incidentally upgraded two Chinese banks -- Bank of China and China Construction Bank. The review did not include any Indian banks.
At the same time, the rating agency giant has kept its ratings unchanged for a handful of big European names like BNP Paribas, Credit Agricole and Deutsche Bank.
Another agency Moody's has also hinted at possible rating downgrades for some European banks.
A credit rating is generally considered as a tool to measure an entity's creditworthiness. The downgrade would make it costlier for the banks to access funds, while their funding needs for day-to-day activities in the overnight debt market could also become more expensive.
On its part, S&P said that the ratings have been reviewed to apply its new ratings criteria for the banks, which it had finalised earlier this month.
The new rating methodology is said to be aimed at a greater focus on the ability of banks to handle the market and economic uncertainties and the likelihood of any support from the government for troubled financial institutions.

The changes have been made in the rating criteria after criticism of various agencies, including S&P, about their alleged inability in foreseeing the financial crisis of 2008 by not truly reflecting the inherent investment risks in their various rating actions at that time.
S&P first proposed the changes in its rating criteria in January, and had later said that the ratings would be reviewed to apply the new methodology in the last quarter of 2012.
Experts said that the first set of bank ratings from S&P, as per the new methodology, indicated towards a fundamental shift in the global banking landscape towards Asia.
Though financial titans of the US and Europe have been downgraded, S&P has upgraded two Chinese banks.     

The banks whose ratings were left unchanged also included Commerzbank, Industrial and Commercial Bank of China, ING Groep, Societe Generale, Banco Santander.
At the same time, S&P has downgraded the outlook for two European giants, Credit Suisse and Deutsche Bank, to 'negative', although their credit ratings have been retained.
Another rating agency major Moody's has also hinted at a possible downgrade of its ratings for some European banks.     

Moody's would soon review ratings for BNP Paribas SA and Societe Generale SA (France's biggest lenders), UniCredit SpA (Italy's largest), Spain's Banco Santander SA, and Swiss giants Credit Suisse AG and UBS AG.
Earlier in September, Moody's had downgraded some US banks, such as Bank of America, Citigroup and Wells Fargo.
Bank of America, as also its Merrill Lynch unit, have been downgraded by S&P to 'A-', from 'A' earlier.
The ratings for each of Goldman Sachs, Citigroup and Morgan Stanley were also cut to 'A-'. At the same time, JP Morgan Chase was downgraded to 'A' from 'A+', while Wells Fargo and Bank of New York Mellon Corp were cut from 'AA-' to 'A+'.