Wall Street lower on Greece; European shares turn negative

Stocks fell on Friday, ending four weeks of back-to-back gains, as political instability resurfaced in Europe and investors braced for a confidence vote in Greece after US markets close.

The Dow Jones industrial average dropped 61.23 points, or 0.51 percent, to 11,983.24. The Standard & Poor's 500 Index lost 7.92 points, or 0.63 percent, to 1,253.23. The Nasdaq Composite Index fell 11.82 points, or 0.44 percent, to 2,686.15.

European shares fell with Italian banks among the biggest losers as the country's bond yields hit euro lifetime highs after embattled Italy refused financial support from the International Monetary Fund.

The FTSEurofirst 300 index of top European shares fell 0.9 percent to a provisional close of 981.33 points. The index fell 3.6 percent over the week, its first weekly loss in six weeks.

The Nikkei share average rose nearly 2% today, as Greece appeared ready to abandon a proposed referendum that threatened a plan to contain Europe's debt crisis, but the benchmark still logged a weekly loss in a week plagued by concerns about Europe.

The Nikkei average added 1.9 percent to finish the week at 8,801.40, bringing its weekly loss to 2.8 percent. The broader Topix index gained 1.8 percent to 752.02, falling 2.5 percent for the week.