The 30-share index was trading 130.35 points, or 0.33 per cent, lower at 39,626.46.
According to traders, investor sentiment was boosted by initial trends that suggested a win for the ruling NDA.
BSE Sensex rise led by gains in oil and gas, banking and IT stocks, ahead of the general election results.
Stocks that touched 52-week highs include Bajaj Finance, DCB Bank, Federal Bank, HDFC Bank, ICICI Bank, SRF and Titan.
Both the key indices rallied in the last hour of trade after trading on a tepid note through most part of the day.
The BSE gauge Sensex fell 61.88 points to trade at 37,028 in early deals.
The 30-share index was trading 23.96 points, or 0.06 per cent, lower at 37,439.03.