The Sensex is now down 55 points at 19,923.Maruti has plunged nearly 6% to Rs 1,118, and Mahindra & Mahindra has tumbled 5% to Rs 758.Reliance and ACC have shed 1.7% each at Rs 2,779 and Rs 1,063, respectively.Hindustan Unilever, ITC and TCS are down 1% each at Rs 217, Rs 181 and Rs 1,058, respectively.Reliance Energy has surged 3% to Rs 1,775, and BHEL has gained 2.7% at Rs 2,684.HDFC Bank has advanced 1.4% to Rs 1,662.