Monsanto is hosting meetings across Europe this week to woo Syngenta investors, and two Monsanto top executives said in one of these gatherings that only a due diligence assessment of Syngenta’s operations could tell whether there was room for a higher offer than the 449 Swiss francs per share proposed so far, a person with knowledge of the meeting said on Wednesday. Syngenta confirmed it had not granted the suitor access to privileged business data. “Monsanto is a competitor to many aspects of Syngenta’s business.