The Bombay Stock Exchange benchmark Sensex today rose by over 160 points, in early trade after on selective buying by funds and retail investors in power and metal stocks. The 30-share index gained 150 points at 17,494 points in the noon trade. The wide-based National Stock Exchange index Nifty also regained 5,200 levels in the first five minutes of trading rising by 43 points to 5,212. Marketmen said buying activity picked up after a firming trend in Asian regions following overnight gains in the US markets. Ending of current month settlement in the derivatives contract also fueled the buying activity, they said.