Syngenta shares fell more than 9% on Monday after the European Commission triggered doubts about Chinese state-owned chemical company ChemChina’s $43 billion bid for the Swiss pesticides and seeds group, Reuters reports. The companies met with the EU antitrust authority a week ago in a bid to allay competition concerns about China’s largest-ever foreign investment. They had until Oct. 21 to do so. Commission spokesman Ricardo Cardoso said in an email that the companies had not offered any concessions. This means either the Commission will clear the deal unconditionally by an Oct. 28 deadline or open a full investigation, a process that can take up to five months.