Syngenta's independent directors will ensure its investment-grade rating-COO
February 12, 2016 at 07:32 AM EST
SINGAPORE, Feb 12 (Reuters) - Independent directors at Syngenta AG will have to approve any significant changes at the Swiss seeds and pesticides group after it is bought by state-owned ChemChina, and they will ensure its investment-grade rating is retained, a senior Syngenta executive said.