By Maya Nikolaeva PARIS (Reuters) - European banks may see the outlook on their credit ratings cut as Standard & Poor's looks at possibly reducing the premium it assigns to banks to reflect changes in the level of state support that banks can expect to get in future crises. In revising the premiums S&P would be anticipating new EU rules which from 2016 will force shareholders, bondholders and some depositors to take a loss or "bail in" to help rescue a failed bank before state support kicks in. The EU's Bank Recovery and Resolution Directive which is due to be voted through the European Parliament in April, states that a government capital injection is possible only when a bank bails in at least 8 percent of total liabilities or 20 percent of risk-weighted assets. "We will review the probability of government support for European banks by end-April ... we will probably just change outlooks (to negative) on the ratings," said Arnaud de Toytot, a managing director at Standard and Poor's told reporters on Thursday, meaning that the rating could be changed in one to two years following the move. Standard and Poor's rating of a bank comprises valuation of finances, such as business position, capital and earnings, risk, funding and liquidity, as well as the assessment of systemic importance, and a cut would raise the bank's cost of borrowing. Fitch Ratings revised down its outlook on Societe Generale in March, citing amendments in its credit models that now take into account lower probability of state-support, if needed, in the next one to two years. Societe Generale had to postpone its bond placement due to the change in the outlook. Societe Generale's stand-alone rating is 'BBB+' with S&P but the evaluation of support it might get from the government in case of crisis adds one notch to the 'A' - level. Those ratings that already have a negative outlook will probably not be influenced by the revision, S&P said. Another rating agency Moody's said in an email to Reuters that the implications for ratings on banks' senior debt remains unclear although recent decisions imply an increasingly negative outlook for European banks' ratings. (Reporting by Maya Nikolaeva; Editing by Greg Mahlich)