Domestic equity benchmarks BSE Sensex and NSE Nifty started on a volatile note Wednesday as investors turned jittery on weak domestic and global cues amid continued foreign fund outflow.

After swinging nearly 200 points in the first half hour of the session, the 30-share index was trading 29.49 points, or 0.07%, higher at 39,845.97 at 0945 hours. Similarly, the broader Nifty was quoting 6.60 points, or 0.05%, up at 11,916.90.

In the previous session, the BSE gauge settled 129.98 points, or 0.33%, higher at 39,816.48, and the Nifty rose 44.70 points, or 0.38%, to finish at 11,910.30.

On a net basis, foreign institutional investors sold equities worth Rs 512 crore, while domestic institutional investors purchased shares to the tune of Rs 141.09 crore, provisional data available with stock exchanges showed Tuesday.

Top gainers in the Sensex pack in early trade included Yes Bank, IndusInd Bank, Asian Paints, M&M, Axis Bank, NTPC and PowerGrid, rising up to 2.23%.

On the other hand, Vedanta, ONGC, HDFC, Tata Steel, ITC, TCS and HUL fell up to 1.63%.

According to traders, investors were cautious ahead of the Union Budget, scheduled for Friday. Domestic investors followed cues from other Asian equities which remained volatile amid fears of a global economic slowdown amid weakening global manufacturing growth, they said.

Shanghai Composite Index, Hang Seng, Nikkei and Kospi were trading on a negative note in their respective early sessions. Bourses on Wall Street ended higher on Tuesday.

Fall in GST collections, slow progress of monsoon too weighed on market mood here, traders added. On the currency front, the Indian rupee appreciated 13 paise to 68.81 against the US dollar.

Meanwhile, the global oil benchmark Brent crude futures were trading 0.34% higher at 62.61 per barrel, after the Opec bloc of oil producers on Tuesday formally signed a new charter of cooperation with major allies including Russia, one day after thrashing out the document at a marathon meeting.