The Sensex slipped into negative territory, after opening 14 points up at 7,765.
The Nifty opened with a gain of 2 points at 2,370.
The Sensex finally plunged by 135 points to close at 7616, following selling pressure in tech, pharma, auto and banking counters.
The Nifty closed at 2,326, down 42 points.
Tech majors Infosys, Wipro, TCS and Satyam declined.
Bharti, Reliance, Satyam, SBI, Bajaj, Cipla, Dr Reddy's, HDFC Bank, ICICI Bank, Maruti and ONGC also declined.
Tata Motors and ITC made gains.