China National Chemical Corp said it filed for US antitrust approval with the Federal Trade Commission for its proposed $43 billion takeover of Swiss agrochemical company Syngenta AG.

ChemChina has submitted documentation required by the Hart-Scott-Rodino Act and expects the US antitrust process to be "on track," the company said in an email. The FTC, which oversees merger reviews along with the Justice Department, has 30 days to clear the proposed tie-up or issue a second request, seeking more information and a longer review period.

The proposed transaction already has been cleared by a US national security panel and won antitrust approval in Australia, where there are overlapping products between Syngenta and ChemChina's Israeli-based generic agrochemical maker Adama.