The Sensex opened marginally weak at 6,443 over its previous close. After dipping to a low of 6,432, the Sensex bounced back into the green to touch a high of 6,468 as most of the counters registered decent gains after a weak start. The Sensex is now up 21 points at 6,466, while the Nifty has added nine points to 1,995.SBI has gained a per cent (Rs 6) to Rs 621, while HDFC Bank is up Rs 5 at Rs 540. ICICI Bank, however, is down a tad at Rs 393.ONGC and HLL are up a rupee each at Rs 877 and Rs 132, respectively. Reliance is down a rupee at Rs 541. Wipro is up a per cent (Rs 6) at Rs 644. Infosys has resumed weak at Rs 2,055 - down Rs 8.Maruti has jumped 1.85% (Rs 8) to Rs 441, Bajaj and Tata Motors are up a per cent each at Rs 1,134 (up Rs 7) and Rs 434 (up Rs 5), respectively.Grasim and Gujarat Ambuja have gained a per cent each to Rs 1,150 (up Rs 7) and Rs 445 (up Rs 3), respectively.Ranbaxy has clocked a per cent gain (Rs 7) to Rs 972. Dr. Reddy's and Cipla are marginally up at Rs 655 and Rs 278, respectively.HPCL has added 1.10% (Rs 4) to Rs 331.