The Sensex opened with a positive gap of 16 points at 6,695, which turned out to be the high for the day.After drifting into negative zone in early deals, the index continued to be weak right through the session today. After hitting a low of 6,640 in late noon deals, selective buying at lower levels saw the Sensex finally close with a loss of nine points at 6,670.While 18 index scrips declined with a volume of 82 lakh shares totalling Rs 442 crore, 11 advanced with a volume of 1.21 crore shares for 369 crore.Heavyweights largely finished on a weak note. Reliance was down nearly a per cent (Rs 4) at Rs 539. SBI was down Rs 4 at Rs 661. ITC also dropped Rs 4 to Rs 1,313. HLL, however, was a notch higher at Rs 152. Infosys added Rs 15 to Rs 2,184. While Satyam declined more than a per cent (Rs 5) to Rs 416, Wipro lost Rs 5 to Rs 706. Hero Honda declined 1.5% (Rs 9) to Rs 555. Bajaj was down more than a per cent (Rs 11) at Rs 1,067. Maruti and Tata Motors declined marginally today.HPCL slipped 2% (Rs 7) to Rs 363. BHEL dropped over a per cent (Rs 9) to Rs 851. HDFC Bank was down 1.3% (Rs 7) at Rs 562. While Grasim was up 1.4% (Rs 18) at Rs 1,379, Gujarat Ambjua was marginally higher at Rs 447. ACC finished unchanged at Rs 374. Tata Power zoomed over 3% (Rs 12) to Rs 421. Bharti gained 2% (Rs 5) to Rs 220. Dr. Reddy's, Ranbaxy, ICICI Bank and L&T also closed with gains.Select scrips logged sharp gains on news-based buying.Crisil was locked at its 20% upper limit at Rs 680 - a gain of 20% (Rs 113) - after S&P made a conditional offer to hike stake to 51% at Rs 680 per share. The counter clocked an unusally high volume of 48,312 shares as against the 2-week average quantity of 1,170 shares.GlaxoSmithKline Pharma was up 2.5% (Rs 17) at Rs 703 after the company announced its FY04 results and a dividend of Rs 24 per share.Essar Shipping topped the volume chart with over 1.87 crore changing hands today followed by JCT at 85 lakh shares and Bharti Tele with a volume of 69 lakh shares.