The Sensex is now down 84 points at 13,681.Dena Bank has surged nearly 7% to Rs 37, on news that Canara Bank may buy the bank. Meanwhile, Canara Bank was up 1% at Rs 219.There were no major gainers among the index stocks.HDFC and Ranbaxy have slipped 1.3% each to Rs 1,587 and Rs 384, respectively. ACC is down 1% at Rs 877.