S&P places 15 euro countries on watch for downgrade

Standard & Poor's placed ratings of 15 euro zone countries on watch with negative outlook on Monday, hinting that nations' ratings depend on the outcome of a summit of European Union leaders on December 9.

"The S&P move is yet another signal that euro area countries must take decisive action to deal with the crisis or else the problems will spread from Greece and others with the most acute fiscal problems to the rest of the euro zone," said Phillip Swagel, a professor of economics at the University of Maryland's School of Public Policy.