The Sensex has erased all its gains and now slipped into red to 15,601 - down three points.Reliance Energy has soared over 2% to Rs 902. Tata Steel has advanced 1.3% to Rs 713, and Ambuja Cements has added 1% to Rs 146.Satyam has shed 1.8% to Rs 423, and TCS has slipped 1.4% to Rs 1,009.Out of 2,594 stocks traded so far, 1,450 have advanced, 1,086 have declined and 58 are unchanged.