Benchmark equity indices Sensex and Nifty declined on Monday due to profit-taking by investors after a record-breaking rally in the last week and a largely weak trend in Asian markets. Snapping its three-day rally, the 30-share BSE Sensex declined 168.66 points or 0.24 per cent to settle at 71,315.09. During the day, it fell 341.46 points or 0.47 per cent to 71,142.29. The Nifty fell by 38 points or 0.18 per cent to 21,418.65.