Benchmark indices extended their losing streak to the sixth straight session on Friday, with the Sensex declining 135 points in choppy trade amid mixed global markets, unabated foreign fund outflows, and rising crude oil prices.

The BSE benchmark declined 135.37 points or 0.26 per cent to settle at 51,360.42. During the day, the benchmark faced volatility and tanked 574.57 points or 1.11 per cent to its one-year low of 50,921.22.

The NSE Nifty went lower by 67.10 points or 0.44 per cent to end at 15,293.50.

From the Sensex pack, Titan, Wipro, Dr Reddy's, Asian Paints, Sun Pharma, PowerGrid, Larsen & Toubro, UltraTech Cement, Maruti, TCS and Hindustan Unilever were the biggest laggards.

On the other hand, Bajaj Finance, Bajaj Finserv, Reliance Industries and ICICI Bank were among the gainers.

In Asia, markets in Tokyo and Seoul ended lower, while Hong Kong and Shanghai posted gains.

European markets were trading in the green in mid-session deals.

Stock exchanges in the US ended sharply lower on Thursday.

"The dominant theme impacting equity markets globally is the synchronised global monetary tightening and the consequent fears of economic slowdown," said V K Vijayakumar, Chief Investment Strategist at Geojit Financial Services.

Meanwhile, international oil benchmark Brent crude jumped 0.96 per cent to USD 120.96 per barrel.

Foreign institutional investors (FIIs) remained net sellers in the capital market, as they sold shares worth Rs 3,257.65 crore on Thursday, as per exchange data.