Red-Hot M&A Target Comes With a Little Legal Problem in the U.S.

For months now, Swiss seed maker Syngenta AG has been publicly courted by the likes of Monsanto Co. and China National Chemical Corp., part of a historic consolidation wave sweeping the agri-chemicals business.

But lurking behind any deal are lawsuits against Syngenta in which U.S. farmers and grain handlers are claiming losses of up to $6 billion. The suits in federal and state courts accuse Syngenta, the world’s third-largest seed company, of putting growers at risk by selling a genetically modified corn seed, engineered to fend off insects, without first obtaining Chinese import approval. Officials there rejected the grain in 2013, pushing down its price and crimping sales for farmers, plaintiffs say.