NEW DELHI: The top 10 most valued companies on the 30-share Sensex saw their combined market valuation plummet by Rs 84,209 crore last week, with ONGC and RIL taking the biggest hit in an overall weak stock market. On a weekly basis, the Sensex lost 1,190.48 points, or 4.51 per cent, to 25,201.90. This is the fourth straight weekly plunge for the index. The market valuation of ONGC shrank Rs 15,357.1 crore to Rs 1,93,011.86 crore. RIL’s market capitalisation tumbled Rs 11,527.8 crore to Rs 2,70,579.56 crore, while that of HDFC fell Rs 9,229.71 crore to Rs 1,80,038.45 crore. The market cap of ITC narrowed Rs 8,905.99 crore to Rs 2,53,901.04 crore while Infosys lost Rs 8,475.72 crore to Rs 2,46,645.92 crore. HDFC Bank saw an erosion of Rs 7,739.77 crore at Rs 2,50,623.13 crore and CIL took a hit of Rs 6,726.92 crore to its m-cap at Rs 2,19,019.94 crore. The market capitalisation of Sun Pharma was down by Rs 6,352.99 crore at Rs 2,06,604.59 crore as HUL lost Rs 5,741.39 crore to Rs 1,79,675.61 crore. Similarly, TCS saw a dip of Rs 4,152.51 crore in m-cap at Rs 4,99,367.90 crore. In terms of ranking, TCS took the lead, followed by RIL, ITC, HDFC Bank, Infosys, CIL, Sun Pharma, ONGC, HDFC and HUL.