Indian stock markets on Tuesday opened on a flat note with BSE Sensex registering a rise of nearly 40 points in morning trade at 35,394.77.Nifty, on the other hand, dipped marginally on Tuesday at 10,621.45 over its previous close on Monday at 10,628.60. On Monday, Indian shares rose about 1 per cent in volatile trading, led by gains in index heavyweights HDFC Bank Ltd and consumer goods giants Hindustan Unilever Ltd and ITC Ltd.The benchmark BSE Sensex ended 1.07 per cent higher at 35,354.08, while Nifty climbed 0.97 per cent higher to 10,628.60.Hindustan Unilever jumped nearly 4 per cent. ITC advanced 1.8 per cent.The domestic markets yesterday opened in green with Sensex registering an increase of over 130 points, at 35,118.09 in morning trade. It crossed over 150 points shortly after opening on Monday. Nifty, on the other hand, rose by around 41 points at 10,568.30 as compared to its last closing at 10526.75 on Thursday.