Mumbai, Sept. 19 -- India's stock markets opened on a weak note on Friday as investors reacted to geopolitical concerns after the United States announced the revocation of sanctions waiver for Iran's Chabahar Port, effective September 29. The move weighed on investor sentiment in early trade.

The Nifty 50 index opened at 25,365.20, down by 58.40 points or 0.23 per cent, while the BSE Sensex started at 82,835.73, registering a decline of 178.23 points or 0.21 per cent.

Market participants attributed the pressure to the Trump administration's fresh decision to withdraw the special waiver that had been granted to India in 2018 for operations at the Chabahar Port in Iran.

According to a statement issued by the US Department of State, opera...