Cash-rich Reliance Industries (RIL), whose stock price has been battered over the past year, will consider a share buy back on Friday, the company said, sending its shares up as much as 4% in early trade.

RIL, an energy-focused conglomerate controlled by Mukesh Ambani, country's richest man, saw its share price tumble 35% in 2011, helping drag the benchmark Sensex down 25% for the year, making India one of the worst-performing markets anywhere.

"This was not completely unexpected, as there was a feeling that if the stock was impacted to this extent, the company would move to buy up shares," said Deven Choksey, chief executive officer and managing director of KR Choksey Shares & Securities.

"The shares are very attractive at current levels, and when there is a chance to make 20% return on their capital, RIL doesn't miss that kind of opportunity," he said.

RIL, which has been using cash to make acquisitions and expand beyond its core energy and refining business, is India's most valuable listed company. It's last share buy back was in 2005.

RIL had cash and cash equivalents of Rs 61,490 crore as of the end of September.

The stock has been weighed down by worries about slowing output at the company's offshore gas fields.

Controlling shareholders in RIL own 44.71% of the stock, according to the Bombay Stock Exchange.