The index was in a red for a whole day due to selling pressure on realty, banking, capital goods and power stocks.
The index moved in a range of 207 points between 15,052 (low) and 15,259 (high).
The Sensex finally ended (provisional) with a loss of 338 points at 15,084.
The markets breadth was negative - out of 2,716 stocks traded, 1,802 declined, 847 advanced and 67 were unchanged today.
The NSE Nifty ended (provisional) with a loss of 77 points at 4,505.