Some bargain buying by investors at lower levels helped.
The BSE Sensex was trading at 27,543.18, up 30.92 points, or 0.11 per cent, from its previous close of 27,512.26 at 1233 hours. It opened higher at 27,635.25 and went on to touch a high of 27,791.10.
The 50-share Nifty too moved up 9.85 points, or 0.12 per cent, to 8,359.30 at 1233 hours.
Brokers, however, said the disruption in Parliament by the Opposition has clouded the outlook for stocks.
On the other hand, Tata Steel fell 3.59 per cent followed by Vedanta and Hindalco.