All the sectoral indices closed in the red, with Nifty Realty, Nifty Auto, Nifty IT, Nifty Metal and Nifty Private Bank falling the most. The Sensex settles at 73,709.69, down 143.21 points, or 0.19%, from its previous close of 73,852.90, while the Nifty ends at 22,811.35, down 77.60 points, or 0.34%.