Ranbaxy Laboratories Ltd, India's top drugmaker, said on Thursday its chief financial officer had resigned, the third top official to quit after Japan's Daiichi Sankyo took majority control.

The company, with annual sales of about $1.7 billion, did not give a reason for Omesh Sethi's resignation but said it was effective Jan. 25.

Shares in Ranbaxy, which the market values at about $5 billion, fell as much as 1.7 percent to 554.15 rupees in a subdued Mumbai market.

Sethi's exit comes less than six months after then chief executive Atul Sobti left citing a rift in strategy.

Daiichi had bought the holdings of Chairman and CEO Malvinder Singh and his family in 2008 and later made an open offer, in a deal valued at $5.4 billion, giving the Japanese No.3 drugmaker a launch pad to expand its generic offerings.

Singh stepped down from the company in 2009.