UPDATE 2-Pfizer may make counter bid for Ranbaxy - report

(Adds Pfizer no comment)

MUMBAI, June 13 (Reuters) - Pfizer Inc (PFE.N: Quote, Profile, Research, Stock Buzz) may bid for Ranbaxy Laboratories Ltd (RANB.BO: Quote, Profile, Research, Stock Buzz), countering a $4.6 billion offer by Japan's Daiichi Sankyo Co Ltd (4568.T: Quote, Profile, Research, Stock Buzz) for the Indian generic drug maker, the Business Standard newspaper said.

Ranbaxy's shares jumped more than 4 percent on the report while Daiichi Sankyo's shares dropped 2 percent.

Pfizer, the world's largest drug maker, may bid for the about 65 percent of Ranbaxy held by institutions and public shareholders, the newspaper reported on Friday, citing unidentified sources familiar with the development.

Daiichi Sankyo struck a deal on Wednesday worth up to $4.6 billion to take control of Ranbaxy, with the two companies seeking to become a pharmaceuticals powerhouse that sells both branded drugs and generics.

Japan's third-biggest drugmaker agreed to acquire 34.8 percent from Ranbaxy's founding Singh family and then make an open offer for up to an additional 20 percent in line with Indian regulations.

The newspaper said Pfizer held talks with the Ranbaxy founders for a possible acquisition a year earlier and may now offer to buy out the stake held by lenders and other investors.

"That is speculation," a Ranbaxy spokesman said. "We have a binding contract with Daiichi. It is a final contract."

On Thursday, when asked in Tokyo what he would do if another bidder appeared at a higher price, Ranbaxy Chief Executive Malvinder Singh said, "This is a firm and binding agreement between the two sides."