Standard & Poors has cut Greece's credit rating another two levels, putting Greek government bonds deeper into “junk” status.

S&P said Wednesday that it regards a possible restructuring of Greece's debt by the European Union as a selective default and says the likelihood of a future default is high.

Last week's second international bailout for Greece includes a voluntary bond swap by private investors — trading in their Greek government bonds for ones with lower interest rates or lower face value to help Greece emerge from debt. S&P calls this a negative development for investors.

Two other rating agencies — Moody's and Fitch's — have also rated Greek bonds as junk.

The EU and IMF approved another $157 billion bailout for Greece after last year's $160 billion loan failed to bring about any major improvements to the Greek economy.