The Sensex is now down 794 points at 16,670.The NSE Nifty is down 249 points at 4,871.Reliance Energy has tumbled over 12% to Rs 1,723. Reliance Communications has slumped 7.3% to Rs 599.HDFC, Reliance (RIL), SBI and Larsen & Toubro have plunged 6% each to Rs 2,625, Rs 2,274, Rs 2,058 and Rs 3,316, respectively.ONGC and ICICI Bank have dropped over 5.5% each to Rs 940 and Rs 1,007, respectively. NTPC has shed nearly 5% at Rs 193.HDFC Bank has slipped 4.5% to Rs 1,380. Mahindra & Mahindra and Hindustan Unilever have declined around 4% each to Rs 618 and Rs 203, respectively.Tata Steel and Bharti Airtel are down nearly 4% each at Rs 722 and Rs 850, respectively.Satyam has soared 3% to Rs 422, and TCS has rallied 2.5% to Rs 923. Infosys has moved up over 2% to Rs 1,585.