Shares of Ranbaxy rose 3.8 percent to 566.75 rupees in Mumbai trading, for the biggest gain since Nov. 1.

The Food and Drug Administration said today that it approved Ranbaxy’s copy on Nov. 26. Ranbaxy will have exclusive rights to sell the generic drug for six months, according to a report from PharmAsia News on Nov. 27.

Krishnan Ramalingam, a spokesman for Gurgaon, India-based Ranbaxy, declined to comment.

“This is a significant positive development,” Vikas Sonawale, an analyst at Religare Securities who has a “buy” rating on the stock, wrote in a note to investors on Nov. 27. The drug could have sales of $252 million over six months, Sonawale wrote.

Religare Securities’ parent Religare Enterprises Ltd. is controlled by the billionaire brothers Malvinder and Shivinder Singh, who sold their family’s 35 percent stake in Ranbaxy to Tokyo-based Daiichi Sankyo Co. in 2008.

Sales of Aricept, the world’s top-selling Alzheimer’s disease medicine, rose 6.3 percent to 322.8 billion yen ($3.8 billion) in the year ended March 31, Eisai said in May.

Ranbaxy, 64 percent owned by Daiichi Sankyo, received tentative FDA approval for generic Aricept in September.

Source: www.bloomberg.com