The Sensex marginally higher at 12,792, and touched a high of 12,805, before slipping into the negative zone to a low of 12,712.The index is now down 20 points at 12,767.ONGC has shed 3% to Rs 822. Dr.Reddy's has advanced 1.4% to Rs 756. NTPC and Tata Steel are up around 1% each at Rs 163 and Rs 442, respectively.