Snapping a two-day rally, the Sensex at the Bombay Stock Exchange declined 110 points, or 0.6 percent, to 18,682, on profit-booking by investors, amid largely subdued Asian and European markets, on Friday. The Sensex had gained 215 points in last two trading sessions. The Nifty at the National Stock Exchange fell 34 points, or 0.6 percent, to 5,684.