At noon on Monday, the core equity indices i.e., Sensex and Nifty 50 were seen extending losses amidst weaker global cues with the Sensex giving up 58,000-level mark. The Sensex was at 57,943.41 down by 701.41 points or 1.20 per cent, while Nifty was at 17,617.13 down by 189.11 points or 1.06 per cent from the last trading session.