But if payouts reach 20 billion euros - a possible scenario according to analysts - the German pharmaceuticals company is in danger of losing its "Baa1" investment rating.

Claimants say that their cancer was caused by glyphosate, an ingredient in Roundup, and are demanding million-dollar compensation payments from Bayer, although some researchers contest this finding.

The World Health Organization in 2015 classified glyphosate as "probably carcinogenic to humans", but the U.S. Environmental Protection Agency in September 2017 concluded a decades-long assessment of glyphosate risks and found the chemical was not likely carcinogenic to humans.

In the United States alone there are 11,200 lawsuits pending against Monsanto, which Bayer bought last year for $63 billion, and litigation setbacks have sent Bayer shares plunging in recent months.

Moody's said that settlements involving payments totalling 20 billion euros made from 2020 until 2022 would lead to a leverage ratio above Bayer's current "Baa1" rating.

But if Bayer agreed to make the settlement payments by 2021 its leverage would increase to almost 4.0x which would even stretch even a hypothetical "Baa2" rating.

(Reporting by Tassilo Hummel, editing by Louise Heavens)