Mumbai: Anxiety over the outcome of the Bihar polls, coupled with upcoming U.S. jobs data, dented investors' sentiments in the Indian equity markets and plunged a barometer index by 109 points during the mid-afternoon session on Thursday.

Both the bellwether indices of the Indian equity markets opened in the negative territory in sync with European and Asian markets. Lackluster quarterly results and absence of any major positive triggers eroded investors' confidence.

On Thursday, the wider 50-scrip Nifty of the National Stock Exchange (NSE) was trading in the red. It was lower by 42 points or 0.52 percent at 7,998.50 points.

The barometer 30-scrip sensitive index (Sensex) of the S&P Bombay Stock Exchange (BSE) opened at 26,557.80 points, was trading at 26,443.64 points (2.30 p.m.) down 109.28 points or 0.41 percent from the previous day's close at 26,552.92 points.

The Sensex has so far touched a high of 26,557.80 points and a low of 26,373.48 points in the intra-day trade.

Market observers cited that anxiety over Bihar election outcome coupled with upcoming U.S. jobs data and disappointing quarterly results subdued the intra-day trade.

"The weakness emanated from the sell-off in the European markets due to the Volkswagen issue. Domestically, investors were reluctant to chase prices ahead of the crucial jobs data in the U.S. and Bihar election results," Anand James, co-head, technical research desk with Geojit BNP Paribas Financial Services, told IANS.

The U.S. jobs data, to be released on Friday, is expected to give cues on whether the U.S. Fed will raise interest rates in its December meeting.

The U.S. Fed is slated to conduct its Federal Open Market Committee (FOMC) during December.

The FOMC assumes significance as higher interest rates in the U.S. are expected to lead away FPIs (Foreign Portfolio Investors) from emerging markets such as India.

Furthermore, investors avoided taking long positions ahead of the Bihar election verdict which is due on November 8.

Sector-wise, S&P BSE banking index plunged by 237.98 points, healthcare index receded by 207.79 points, capital goods index plummetted by 64.51 points, information technology (IT) index fell by 60.39 points and oil and gas index was lower by 57.36 points.

On the other hand, the S&P BSE fast moving consumer goods (FMCG) index rose by 25.71 points.