The Alliance of Critical Syngenta Shareholders said: "We were also left with a sense that Syngenta’s previously announced share buyback would not occur if the divestitures did not proceed as those divestitures were necessary to fund the share buyback."
Syngenta declined to comment.
In September Syngenta announced plans to divest the seed units.
Monsanto has withdrawn a $46.5 billion takeover bid, which Syngenta had rejected. China National Chemical Corp have also had a bid rejected.
However, a possible Dow and DuPont merger my make it more likely that Monsanto re-approaches Syngenta, as its rivals get bigger and the company feels the need to grow to compete.