The Sensex opened marginally higher (four points) at 6,683, and touched a high of 6,696 in morning deals. Profit-taking at higher levels saw the index drop to a low of 6,641 - an intra-day drop of 55 points - towards the closing bell. The Sensex finally finished the day with a loss of 28 points at 6,651.While 20 index scrips declined with a volume of 1.26 crore totalling Rs 580 crore, 10 advanced with a volume of 39 lakh for Rs 124 crore.Heavyweights finished on a weak note. Reliance declined more than 2% (Rs 12) to Rs 531. Infosys dropped more than a per cent (Rs 29) to Rs 2,088. SBI was also down a per cent (Rs 6) at Rs 650. HLL, however, was up Rs 2 at Rs 146. ITC was marginally higher at Rs 1,314. Cement scrips firmed up after reporting good December shipment numbers. Gujarat Ambuja zoomed 4% (Rs 16) to Rs 424. ACC moved up 3% (Rs 10) to Rs 352, and Grasim was up Rs 14 at Rs 1,341. Hero Honda continued to log gains, and was up nearly 2% (Rs 11) at Rs 611. HPCL gained Rs 5 to Rs 413. ICICI Bank was up Rs 3 at Rs 374. Zee moved up Rs 4 to Rs 176.BHEL was down 2% (Rs 17) to Rs 777. ONGC, Maruti, Reliance Energy, Satyam and Wipro also declined.Dr. Reddy's dropped 2% (Rs 20) to Rs 845. Ranbaxy lost Rs 14 to Rs 1,236.