The BSE Sensex today rose by nearly 100 points in early trade on the back of strong rally in Infosys as market cheered N R Narayana Murthy's return as the company's executive chairman.The 30-share index, which had tanked 455 points in the previous session after GDP fell to decade's low, rose to 19,860 points.The National Stock Exchange Nifty gained 25 points, to trade at 6,011.00 points.