BRUSSELS (Reuters) - China National Chemical Corp (ChemChina) [CNNCC.UL] has sought antitrust approval for its $43 billion bid for Swiss pesticides and seeds group Syngenta (>> Syngenta AG) from the European Union and a decision is expected by Oct. 28.

State-owned ChemChina filed its request on Sept. 23, the European Commission's website showed on Monday.

The EU competition enforcer can either clear the deal, with or without concessions, or it can open a full investigation if it has serious concerns that ChemChina's takeover of the world's largest pesticides maker could harm customers and rivals.

ChemChina cleared one of the biggest hurdles last month when a U.S. national security panel approved what would be the largest foreign acquisition by a Chinese company.

The deal is one of several in the agrochemicals sector, including the planned $130 billion merger of Dow Chemical (>> Dow Chemical Co) and DuPont (>> E I Du Pont De Nemours And Co), Bayer's (>> Bayer AG) $66 billion bid for Monsanto (>> Monsanto Company) and Potash Corp of Saskatchewan's (>> Potash Corporation of Saskatchewan Inc) proposed merger with Agrium (>> Agrium Inc.).

(Reporting by Foo Yun Chee; editing by David Clarke)