Sensex touch down by 580 pts

The BSE benchmark Sensex tumbled by 587 points in the first half of trade on Wednesday, dipping below the 15,500-mark at mid-session on heavy selling ahead of monthly expiry in the derivatives segment and global growth jitters. 

The 30-share barometer, which opened 220 points lower, was down by 586.73 points at 15,478.69 at 1230 hours, led by banking, refinery and IT stocks.

The wide-based National stock Exchange Nifty index was also down by 171.40 points at 4,640.95 at 1230 hours.

Brokers said a fresh bout of selling by funds and retail investors, cashing in on the brief recovery of the equity markets on Tuesday amid a weak trend in global markets, weighed down the trading sentiment.

In addition, they said, expiry of monthly derivative contracts later this week and fresh concerns about the health of the global economy after a downward revision of the US growth rate in the third quarter of 2011 dampened investors' mood.

Meanwhile, Asian stocks fell to their lowest levels in more than six weeks as US equity futures and oil prices dropped on concerns that global economic growth will falter amid the rapidly deteriorating situation in the euro zone.