U.S. markets opened lower as Moody\'s Investors Service downgraded credit ratings for six European countries, including Spain and Italy. Moody\'s also put France and Britain on notice that their triple A ratings were in jeopardy. Britain\'s rating was given a negative status. The U.S. Commerce Department said retail sales rose 0.4 percent in January after falling flat in December. Excluding automobiles, sales rose 0.7 percent in the month of January. In early afternoon trading, the Dow Jones industrial average gave up 45.83 points, 0.36 percent, to 12,828.21. The Standard & Poor\'s 500 index shed 6.56 points, or 0.49 percent, to 1,345.21. The Nasdaq composite index dropped 12.27 points, or 0.42 percent, to 2,919.12. The benchmark 10-year treasury note rose 137/32 to yield 1.931 percent. The euro fell to $1.3111 from Monday\'s $1.3187. Against the yen, the dollar rose to 78.45 yen from Monday\'s 77.57 yen. In Tokyo, the Nikkei 225 index rose 0.59 percent, 52.89, to 9,052.07. In London, the FTSE 100 index shed 0.1 percent, 5.83, to 5,899.87.