The 30-share index resumed higher at 20,510.31 and hovered in a range of 20,584.22 and 20,485.74 before quoting at 20416.63 at 1145 hours, a gain of 74.33 points or 0.36 per cent from its last close.
The NSE Nifty moved up by 18.70 points or 0.31 per cent to 6060.10 at 1145 hours.
Foreign institutional investors continued buying shares with purchases of a net Rs 333.50 crore yesterday, according to provisional data from the stock exchanges.
IT shares firmed up due to depreciation in the value of the rupee against the dollar. In the foreign exchange market, the Indian rupee edged lower to 63.52 against the dollar and was quoted at 63.49 at 1015 hours.
Most Asian stock markets rose for the second day in early trade. Key indices in China, Japan, Taiwan and South Korea rose between 0.45 per cent and 1.66 per cent while indices in Singapore, Hong Kong and Indonesia shed 0.06 per cent to 0.68 per cent.
US stocks gained yesterday, with the Dow Jones Industrial Average extending its record rise, as investors awaited retailer earnings reports to gauge the strength of consumer demand and the likelihood of cuts to monetary stimulus.