Indian equity benchmarks BSE Sensex and NSE Nifty50 are likely to start Tuesday's session in the red, halting a four-day winning streak. Global markets weakened after data showing a slowing US manufacturing sector fuelled concerns about an economic slowdown around the world. Singapore Exchange Nifty futures — an early indicator of the Nifty index — declined as much as 87.5 points or 0.5 percent to 17,305.5 ahead of the opening bell on Dalal Street. Investors awaited more of corporate earnings from India Inc, a day after cigarettes-to-hotels conglomerate ITC and food delivery company Zomato reported their quarterly numbers.