The Sensex is now down 187 points at 12,937.Wipro has tumbled over 4% to Rs 562. Satyam, Tata Motors, HDFC and TCS have plunged around 3% each to Rs 457, Rs 732, Rs 1,528 and Rs 1,226, respectively.Hero Honda, Maruti and Reliance Communications have shed around 2.7% each to Rs 650, Rs 797 and Rs 415, respectively.Infosys and ICICI Bank are down around 2% each to Rs 2,010 and Rs 859, respectively.Ranbaxy has gained 1.5% at Rs 333. BHEL and Dr.Reddy's have advanced over 1% each to Rs 2,281 and Rs 689, respectively.Out of 2,349 stocks traded so far, 1,658 have declined, 639 have advanced and 52 are unchanged.