The Sensex opened with a negative gap of 550 points at 12,713, and soon slipped to a low of 12,558. The index is now down 616 points at 12,647.
Jaiprakash Associates and Bharti Airtel have tumbled around 8% each to Rs 125 and Rs 710, respectively.
HDFC and Reliance Communications have slumped over 6% each to Rs 2,010 and Rs 333, respectively.
DLF and Ranbaxy have shed 6.4% each at Rs 383 and Rs 355, respectively.
Satyam, ICICI Bank, BHEL and Sterlite have dropped nearly 6% each to Rs 329, Rs 528, Rs 1,528 and Rs 414, respectively.
Tata Steel, Reliance Infrastructure and Infosys have slipped around 5.5% each to Rs 448, Rs 784 and Rs 1,490, respectively.
All index stocks are in negative territory with losses in excess of 2% each.