Mumbai: Erasing early gains, the Bombay Stock Exchange benchmark Sensex today plummeted by over 286 points as investors booked profit following mixed bag of quarterly earnings and weak European cues. The Sensex, which had gained 61.67 points at open, rolled down to close lower by 286.62 points to 20,589.09 on mixed corporate results, wherein DLF Ltd and Bharti Airtel profits declined, while Ranbaxy's profits doubled. Similarly, the broad-based National Stock Exchange index Nifty lost 81.45 points to 6,194.25, after rising to 6,296.55 in early trade. The stocks of realty, refinery and IT sectors led the fall. While Asian stocks led by Japan and Hong Kong were in better form, a weak opening in European stock markets this afternoon influenced the trading sentiment. A fall in food inflation to 12.30 per cent for the week ended October 30, from 12.85 per cent in the previous week, also failed to check the downtrend. In the 30-BSE index components, 18 stocks closed lower while 12 ended in the positive zone. Investors were booking profits in select stocks at their existing higher levels as the benchmark jumped 19 per cent this year and scaled to an all-time high on November 5. The heaviest-weighted on the Sensex, Reliance Industries fell by Rs 20.40 to Rs 1,082.05 and second heaviest Infosys Technologies by Rs 27.75 to Rs 3,055.15. The duo, together, carry nearly 23 per cent weightage. The realty sector index suffered the most by losing 3.17 per cent to 3,673.16 as DLF, the biggest developer, lost the most in more than a week after its second-quarter profit decreased 4.5 per cent from a year earlier on higher costs. The stock fell 4.4 per cent to Rs 346.45. All the sectoral indices, including smallcap and midcap were in the red as selling pressure spread over a wide-front.