Leading US equity indices were back near their 52-week lows as persistently weak economic data and renewed worries about the credit market weighed on investor sentiment.

The S&P 500 index ended flat at 1,331.34 points and is about 15 per cent below the 52-week high it set in October. The Dow Jones industrial average slipped 0.1 per cent to 12,258.90 points, while the Nasdaq composite fell 0.6 per cent to 2,258.60. The Nasdaq is almost 21 per cent below its 52-week high.