May 16 (Bloomberg) -- Greece is considering taking legal action against U.S. investment banks that might have contributed to the countryâs debt crisis, Prime Minister George Papandreou said. âI wouldnât rule out that this may be a recourse,â Papandreou said, in response to questions about the role of U.S. banks in the crisis, in an interview on CNNâs âFareed Zakaria GPS.â The program, scheduled for broadcast today, was taped on May 13. Neither Papandreou nor Zakaria mentioned any banks by name. U.S. stocks fell and the euro slumped on concern that Europe wouldnât be able to contain the debt crisis stemming from Greece. The Standard & Poorâs 500 Index declined 1.9 percent May 14, while the euro fell below $1.24 for the first time since November 2008. Papandreou said the decision on whether to go after U.S. banks will be made after a Greek parliamentary investigation into the cause of the crisis. âGreece will look into the past and see how things went,â Papandreou said. âThere are similar investigations going on in other countries and in the United States. This is where I think, yes, the financial sector, I hear the words fraud and lack of transparency. So yes, yes, there is great responsibility here.â Speculators In the days leading up to the May 10 announcement of a loan package worth almost $1 trillion to halt the spread of Greeceâs fiscal woes, European Union regulators were examining whether speculators manipulated the prices of bonds and equities and contributed to the crisis. The Committee of European Securities Regulators said on May 7 it was investigating âexceptional volatilityâ in the markets and would work with other regulators, including the U.S. Securities and Exchange Commission, as part of a coordinated clampdown. European Central Bank President Jean-Claude Trichet said May 6 that he was concerned about speculation in bond markets using credit default swaps. âBy first buying the CDS and then trying to affect market sentiment by going short on the underlying bond, investors can make large profits,â he said. Credit-default swaps are derivatives that pay the buyer face value if a borrower -- a country or a company -- defaults. In exchange, the swap seller gets the underlying securities or the cash equivalent. Traders in naked credit-default swaps buy insurance on bonds they donât own. In the CNN interview, Papandreou said many in the international community have engaged in âGreek bashingâ and find it easy âto scapegoat Greece.â He said Greeks âare a hard-working people. We are a proud people.â âWe have made our mistakes,â Papandreou said. âWe are living up to this responsibility. But at the same time, give us a chance. Weâll show you.â http://www.bloomberg.com/apps/news?pid=20601087&sid=aDxF1YfeViEc&pos=1 He is not naming Goldman Sachs, or....?