Sensex, Nifty on Monday started trade on choppy notes, erasing early gains. The benchmark BSE Sensex, at 9:21 AM, was up by 49.29 points to trade at 34,905.67 while Nifty was at 10,607.00. Pharma and auto stocks witnessed weaknesses, the shares were down by 0.8 per cent. Sun Pharma, Maruti Suzuki India and Cipla - trading around 1-2 per cent lower - were among the top losers on the 50-scrip Nifty index.