By 14:35, Sensex plunged by 12 points at 19,485, and the Nifty down 7 points at 5,889 levels.
On the global front, Japan's Nikkei share average fell on Friday as investors pared exposure to exporters and banks while awaiting the weekend G20 meeting.
A deepening recession in the euro zone also dragged down shares, and sentiment deteriorated in late trade on news that a conservative, former finance ministry bureaucrat is the leading candidate to head the Japanese central bank.
The Nikkei closed down 1.2 percent at 11,173.83 after falling as much as 2.1 percent.
Back home, BSE Realty and Oil & Gas indices have plunged by almost 2% followed by counters like Consumer Durable, Metal, Healthcare, IT, Power and PSU, all slumping by almost 1% each. Apart from FMCG, all the major BSE sectoral indices are trading in negative zone.
Index heavyweight Reliance Inds has dropped by over 2%. According to reports, TCS today surpassed Reliance Industries to become the country's most valued company as the IT major's market capitalisation soared to over Rs 2.83 lakh crore on the back of a spurt in its share price.
Dr Reddy’s Lab is the top Sensex loser, down over 3%. Bank of America-Merrill Lynch downgraded its rating on Dr Reddy's Laboratories Ltd to "neutral" from "buy", saying "a slight" increase in core profit estimates was being offset by a fading US drug pipeline and moderating growth.
Metal shares like Tata Steel, JSPL and Hindalco have fallen between 1-2%.
Auto shares like Bajaj Auto, Maruti Suzuki and Hero Moto have declined between 0.4-2%. Tata Motors is trading marginally in green.
Other notable losers include CIL, Infosys, Cipla, HUL and TCS.
Among other shares, LIC Housing Finance is trading lower by 3% at Rs 244, extending its Thursday’s 6% fall, on reporting disappointing set of numbers for the third quarter ended December 31, 2012 (Q3).
Meanwhile, BSE Midcap index plunged by 0.20% whereas BSE Smallcap index is down 0.98%.
The market breadth in BSE ended unhealthy with 1,766 shares declining and 946 shares advancing.