S&P Downgrades Greece to Junk; Portugal Also Cut

Europe's debt crisis worsened ominously Tuesday when two financially troubled countries— Greece and Portugal—saw their credit ratings downgraded as markets sold off their debt.

Greece was downgraded to junk status by Standard & Poor's, which lowered Portugal's rating as well. The Portuguese downgrade was a sign the European Union's fears of that the debt crisis would spread beyond Greece—and further undermine the euro currency—might be coming true.

The move triggered a major selloff in in global stocks. European shares fell at their fastest rate in more than two months on Tuesday, while the Dow Jones Industrials plunged over 100 points.

US crude oil futures sank more than 2 percent and the euro fell back near a one-year low against the U.S. dollar. Read more