Mumbai, Sept. 16 -- Indian stock markets opened on a muted note on Tuesday as investors adopted a cautious stance, closely tracking the resumption of Indo-US trade negotiations and awaiting the US Federal Reserve's policy outcome later this week.

At the opening bell, the Nifty 50 index stood at 25,073.60, up 4.40 points or 0.02 per cent, while the BSE Sensex opened at 81,851.84 with gains of 66.10 points or 0.08 per cent.

Experts noted that the indices were in "wait and watch" mode, with sentiment subdued ahead of crucial international and domestic developments.

Banking and market expert Ajay Bagga told ANI, "Indian markets are watching as a US trade delegation arrived last night for a day-long negotiation which will set the tone for r...