US stocks opened higher on Friday,with the imminent market debut of Mark Zuckerberg's Facebook helping to lift battered investor sentiment. Still,major indexes were on track to close their worst week of 2012,pressured largely by the ongoing situation in Europe. Facebook raised about $16 billion in one of the biggest initial public offerings in U.S. history,pricing its offering at $38 a share on Thursday. Shares are expected to begin trading around 11 a.m. (1500 GMT). The Dow Jones industrial average was up 23.54 points,or 0.19 percent,at 12,466.03. The Standard & Poor's 500 Index was up 2.74 points,or 0.21 percent,at 1,307.60. The Nasdaq Composite Index was up 7.68 points,or 0.27 percent,at 2,821.37.
