The Sensex is likely to open lower at the opening bell owing to huge declines in the worldwide indices. The index has support around 10,620 levels below which it could slide to 10,300 levels. In case of upside, the index could face stiff resistance around 10,900 levels.BHEL, Atul Auto, Birtannia, Dr.Reddy's, EIH, Mercator Lines, Omax Auto, NTPC, Sterlite, Swaraj Mazda and Swaraj Engines are scheduled to announce their earnings today.