The Sensex has slipped into the negative zone and is now down eight points at 13,179.Dr.Reddy's and HDFC have advanced 2% each to Rs 793 and Rs 1,557, respectively.Gujarat Ambuja and Infosys have gained around 1.5% each at Rs 130 and Rs 2,103, respectively.Cipla, ICICI Bank and Hindalco are the other major gainers.Bajaj Auto has slipped over 2% to Rs 2,735. NTPC has dropped 1.5% to Rs 131.Reliance Energy, Tata Steel, BHEL and Maruto are the other major losers. The market breadth is negative - out of 2,579 scrips traded so far, 1,284 have declined, 1,222 have advanced and 73 are unchanged.