European Union anti-trust regulators are investigating whether state-owned ChemChina's buyout of Swiss chemical giant Syngenta could reduce competition in crop protection products.

EU Competition Commissioner Margrethe Vestager said Friday that "we need to carefully assess whether the proposed merger would lead to higher prices or a reduced choice for farmers."

Syngenta said Tuesday that EU regulators examining the proposed $43 billion takeover have "recently requested a large amount of additional information," which would drag the approval process out into early next year.

The Commission says the transaction would take place in an industry that is already quite concentrated. It says part of the problem is that ChemChina already controls Adama, the largest supplier of generic crop protection products in Europe.