Indian stock markets were trading slightly lower Wednesday as declines in oil & gas and IT sector shares outweighed the gains in metal and realty sectors.

The 30-share BSE Sensex fell 0.19 percent or 33.21 points to 17,392.50 and the 50 share NSE Nifty declined 0.16 percent or 8.35 points to 5,279.60.

The markets opened on a positive note due to the positive cues from the Asian markets and the Wall Street overnight on hopes that major central banks would implement further measures to support the global economy.

Markets pared earlier gains and slipped into the negative territory as declines in oil and gas, IT and FMCG sectors weighed. The overall market breadth was positive with 1542 advances against 971 declines.

In oil & gas sector, HPCL declined 1.66 percent and ONGC fell 1.19 percent while heavy-weight Reliance Industries declined 0.65 percent.

Brent crude oil rose 3.43 percent or $6.44 to settle at $100.68 a barrel Tuesday on news that Tehran was considering a bill to block the Strait of Hormuz to oil tankers linked to countries that support sanctions against it.

IT stocks continued to drag the indexes for the third day on demand concerns.TCS declined 0.78 percent and Infosys fell 0.20 percent.

Metal sector shares rallied on higher commodity prices. Jindal Steel surged 3.75 percent and Sterlite Industries gained 3.32 percent while Sesa Goa rose 2.41 percent.

Meanwhile, an HSBC survey Wednesday showed that India's service sector continued to grow in June though at a slightly slower rate than in May. HSBC's services purchasing managers' index (PMI) declined to 54.3 in June from 54.7 in the previous month. However, it has kept above the 50 mark that signifies growth since November.