After witnessing volatility in the opening deals, the index bounced back from its lows and remained firm through the session.

The Sensex rallied sharply towards the closing hours on relentless buying support in techs, auto, pharma and select PSU stocks, and finally notched up 81 points gains to close at 4,275.

The Nifty has also advanced 29 points to 1,358.

Infosys, after a weak-bound trend on Monday, rallied sharply on Tuesday and touched the day's high of Rs 4,240. It, however, pared its gains towards the closing hours and advanced 4% (Rs 169) to Rs 4,197. Over 297,000 shares were traded on the BSE with a turnover of Rs 123 crore (Rs 1,230 million). While Satyam spurted nearly 6% (Rs 13) to Rs 242, HCL Tech ended with a modest gain of Rs 2 at Rs 163.

Reliance edged higher during the mid-afternoon trades and added nearly 2% (Rs 6) to Rs 410. ITC, which traded in and out of the positive zone during the trading hour, closed with a gain of Rs 2 at Rs 793. HLL moved up 2% (Rs 3) to Rs 187.

HPCL plunged 12% (Rs 45) to Rs 345. The oil major registered volumes of more than 92 lakh (9.2 million) on the BSE with a turnover of Rs 323 crore (Rs 3,230 million).

SBI gathered buying momentum in the afternoon trades and raked in 3% gains (Rs 14) to Rs 438. BHEL, too, gained momentum in the mid-afternoon deals and ended 3% higher (Rs 11) at Rs 360. MTNL, however, closed down a per cent at Rs 117.

Ranbaxy clocked 4% gains (Rs 40) to Rs 1,011. Cipla and Glaxo traded with steady gains and added Rs 9 to Rs 1,013 and Rs 2 to Rs 452, respectively. Dr. Reddy's ended with a loss of Rs 6 at Rs 1,141.