The BSE-30 share barometer Sensex resumed higher at 19,997.38 and firmed up further to 20,086.43 points on renewed buying as market regulator Sebi allowed overseas entities to invest in government securities without any auction mechanism.
Higher advices from global markets coupled with gain in rupee value against the dollar also boosted the market sentiment.
However, it trimmed its earlier gains and was quoted at 19,945.98 points at 1030 hours, still showing a gain of 213.22 points or 1.08 per cent from last weekend's level.
Meanwhile, foreign institutional investors (FIIs) sold shares worth net Rs 98 crore on last Friday, as per provisional data from stock exchange.
Asian stocks rose in early trade after Lawrence Summers withdrew from the race to be the next Federal Reserve chairman, paving the way for Janet Yellen, who some investors say may favour a slower reduction in US stimulus.
Key benchmark indices in Taiwan, Hong Kong, Singapore, South Korea and Indonesia rose by 0.56 to 1.82 per cent while China's Shanghai Composite fell by 0.24 per cent.