Mumbai, Aug 11 (IANS): The key Indian equity indices -- the BSE Sensex and the NSE Nifty50 -- traded deep in the red during the post-afternoon session on Friday as negative global cues subdued investors' risk-taking appetite.

According to market observers, investors booked profits ahead of quarterly results announcements of major companies like State Bank of India, Bank of Baroda, BPCL, Cipla and Hindalco, among others.

During the post-afternoon session, the Nifty50 of the National Stock Exchange (NSE) traded lower by 75.70 points, or 0.77 per cent, at 9,744.55 points -- sinking below the psychologically important 9,800 points-level.

The 30-scrip Sensitive Index (Sensex) of the BSE, which opened at 31,355.92 points, traded at 31,305.38 points -- down 225.95 points, or 0.72 per cent, from its previous close at 31,531.33 points.

The Sensex has so far touched a high of 31,379.20 points and a low of 31,194.87 points during the intra-day trade.

The BSE market breadth was skewed in favour of bears -- with 1,409 declines and 942 advances.

"Benchmark indices traded lower by 1 per cent, extending falls for the fifth straight session, following a crack in the US stocks during the overnight trade on escalating geopolitical tensions over Korea," Dhruv Desai, Director and Chief Operating Officer of Tradebulls, told IANS.

"Asian stocks also followed the trend and traded lower."