The BSE benchmark oscillated between gains and losses in a range-bound session on Wednesday, before finally closing 152.18 points or 0.29 per cent lower at 52,541.39, an over 10-month low.
The index has now lost 2,778.89 points in four days.
Similarly, the broader NSE Nifty declined by 39.95 points or 0.25 per cent to end at 15,692.15.
NTPC was the top laggard in the 30-share Sensex pack, declining 2.02 per cent, followed by Infosys, Reliance Industries, Wipro, HUL, Tech Mahindra, PowerGrid and ITC.
On the other hand, Bajaj Finserv, Bajaj Finance, Tata Steel, Larsen & Toubro, SBI, Asian Paints and M&M were among the gainers, climbing as much as 4.24 per cent.