Mirroring weakness in global markets, the Sensex opened with a marginal gap of 18 points at 14,345. Some buying in early trades saw the index rebound into the positive zone and touch a high of 14,390.The index, however, could not hold gains for long and slipped back into the negative zone. The index drifted lower as the day progressed and any attempt for a pull-back was met with stronger selling pressure.Heavy selling towards the end saw the index tumble to a low of 14,174 - down 216 points from the day's high. The Sensex finally ended with a loss of 145 points at 14,218.