Indian equity benchmarks Sensex and Nifty50 are likely to start Thursday's session on a muted note. At 8:40 am, Nifty futures trading on Singapore Exchange -- an early indicator of NSE's Nifty50 benchmark index in India -- were up five points at 18,258.5, having risen as much as 28 points earlier. Analysts expect volatility in the market to continue ahead of the expiry of monthly derivatives contracts due by the end of the session..