The BSE Sensex on Friday fell over 500 points immediately after RBI's mid-quarter monetary policy review.
The 30-share index was down 2.48 per cent or 512.56 to 20,124.60 at 11.30 am.
In early trade, the index was trading 60 points down from from its three-year highs on Thursday.
Snapping its four-day long rising streak, the 30-share barometer lost by 60.47 points, or 0.29 per cent, to 20,586.17 with metal, banking, consumer durables, IT and FMCG sector stocks succumbing to profit-booking.
The index had climbed 684 points yesterday to an almost three year high.
The wide-based NSE Nifty fell 8.75 points, or 0.14 per cent, to 6,106.80.
Brokers said fresh selling, mostly of profit-booking nature, by participants before the Reserve Bank's mid-quarter monetary policy review today, mainly attributed fall in stock prices.
Besides, a firming trend in the Asian region also supported the upside, they said.
In the Asian region, Japan's Nikkei up by 0.24 points in early trade, Hong Kong's exchange remained closed today.
The US Dow Jones Industrial Average ended 0.26 per cent lower in the previous session.