Syngenta Chief Executive Officer Mike Mack has informed the Swiss company's board of his intention to step down, Syngenta said. Mack will be leaving the company at the end of October 2015.

Chief Financial Officer John Ramsay is appointed CEO ad interim until the appointment of a new chief executive.

"I believe that this is an appropriate time for the company to benefit from the perspectives of a new leader," Mack said, calling current market conditions challenging. "I wish John every success in his new role."