Equity benchmark Sensex ended marginally lower after a choppy session on Friday as investors weighed the fiscal impact of the government's economic stimulus. After slumping over 350 points during the day, the 30-share index pared most losses to settle 25.16 points or 0.08 per cent lower at 31,097.73. Similarly, NSE Nifty slipped 5.90 points, or 0.06 per cent, to close at 9,136.85.