Ranbaxy Laboratories Ltd, India's largest pharmaceutical company, announced today that its chief executive officer and managing director Atul Sobti has resigned.

Sobti, who had taken charge a year ago, is reported to have had major differences with the management of Daiichi Sankyo, which announced plans for a friendly acquisition of the Indian pahrma firm in June 2008 (See: Japan's Daiichi Sankyo to acquire majority stake in Ranbaxy)

Arun Sawhney, who is currently president of Ranbaxy's global pharmaceutical business, will take over as managing director, the company said in a statement.

Sobti's resignation takes effect from 19 August. Sawhney will take over as managing director from 20 August, the company said, but did not announce a replacement for the chief executive position.

Sobti decided it was the ''right time to step down and was on happy terms with the rest of the board,'' said Masaya Tamae, a spokesman for Daiichi Sankyo Co. The Tokyo-based company bought a 64 per cent stake in Ranbaxy in 2008. Daiichi thus controls the company, with two seats on the seven-member board.

Under Sobti's tenure, Ranbaxy recovered from its first net loss in eight years. The company loses a manager with experience working in Japanese-linked companies including Hero Honda Motors Ltd, 26 percent owned by Tokyo-based Honda Motor Co.