According to sources, exchanges system is not able to handle such a large number of transactions at the closing time.
The 30-share BSE Sensex stabilised in afternoon trade and settled with gains of 42.28 points or 0.10 per cent at 40,487.43.
The US Federal Reserve interest rate decision on Thursday will be a major event that would be keenly tracked by markets globally.
The BSE Sensex settled at 40,445.15, down 334.44 points or 0.82 per cent.
The BSE gauge Sensex moved 103.13 points higher to trade at 40,882.72 in opening deals.
At the closing bell, the 30-share BSE Sensex was lower by 70.70 points or 0.17 per cent at 40,779.59.
BSE Sensex was trading 100.56 points, lower at 40,749.73 at 1149 hours.
The 30-share BSE Sensex was trading higher by 84.17 points at 40,934.46 in n opening deals.
Sectorally, BSE metal index rose the most by 1.66 per cent, followed by bankex and IT indices.
The 30-share BSE Sensex was down 119.42 points or 0.29 per cent to 40,556.03 in early deals.