US grain merchant Archer Daniels Midland Co has settled a lawsuit with Syngenta over the seed company's launch of a biotech corn strain that roiled grain exports to China, according to regulatory documents filed on Friday. ADM sued Syngenta four years ago for selling the corn variety known as Agrisure Viptera or MIR 162 before it was approved for import by China, an importer on US grain. China rejected US corn cargoes that contained the unauthorized strain, which caused financial losses for ADM, according to the lawsuit.

China ultimately approved imports of Viptera corn in 2014. ADM and Syngenta reached a confidential settlement over the matter in December, according to an annual report the grain handler filed with the US Securities and Exchange Commission.

Cargill Inc, another major grain handler, and US farmers also sued Syngenta. Last year, Syngenta, now owned by ChemChina, agreed to settle farmers' lawsuits for close to $1.5 billion. The Cargill case is set for trial in September, according to Syngenta.

"Syngenta is continuing to defend against the claims of other exporters, and continues to believe that American farmers should have access to the latest US-approved technologies to help them increase their productivity and crop yield," spokesman Paul Minehart said in an email.

Copyright Reuters, 2018