The Sensex opened with a negative gap of 20 points at 9294. The index soon slipped to a low of 9236, and is now down 66 points at 9248.Wipro up 3.5% following its Q3 numbers is the sole gainer among the index stocks.Ranbaxy has slipped 2% to Rs 378.HDFC Bank, ONGC, Reliance Energy, SBI, Larsen & Toubro, Tata Steel, ACC, ITC, Grasim, NTPC, Maruti and Tata Motors are down 1-2% each.