Mumbai: The BSE benchmark Sensex fell by almost 52 points in opening trade on Thursday, extending its three-day losing streak on weak cues from Asian peers amid fears that the euro zone debt crisis will worsen.

The 30-share Sensex, which has lost nearly 340 points over the past three sessions, fell by another 51.77 points, or 0.30 percent, to 17,413.08 in opening trade on Thursday, with metal, oil and gas, auto and banking stocks leading the fall.

In a similar fashion, the wide-based National Stock Exchange Nifty index shed 17.85 points, or 0.34 percent, to 5,240.60.

Brokers said a weakening trend on other Asian bourses amid worries over the debt crisis in the euro zone dampened the trading sentiment at home, accelerating selling by foreign funds and other participants.

In the Asian region, Hong Kong's Hang Seng index was down by 2.42 percent in early trade on Thursday, while Japan's stock market was closed for a national holiday. The Dow Jones Industrial Average in the US closed 1.53 per cent higher in Wednesday's trade.