However, Bayer shares soared as much as 11% on the news, though they quickly shed most of their gains after Bayer denied reports of the settlement.

Bayer acquired Roundup and other glyphosate-based weedkillers as part of its $63 billion takeover of Monsanto last year. At one point, they were the best performing shares on the DAX.

Bayer shares had lost more than one-third of their value, or roughly 30 billion euros ($34 billion), since last August when a California jury found that Monsanto should have warned customers about the alleged cancer risks from Roundup.

Plenty of legal risk remains for Bayer. The company said this week that the next US. glyphosate lawsuit scheduled to be heard in St. Louis, Missouri, would likely be postponed and the company added on Friday that the following St. Louis case slated for September had been postponed to allow for settlement talks.

Bayer's Chief Executive Werner Baumann last week said the company would consider settling with US plaintiffs only on reasonable terms, and if it "achieves finality of the overall litigation."

He added at the time the group was "constructively engaging" in a court-ordered process with mediator Ken Feinberg on the cases heard in federal court. Most of the pending cases, however, have been filed with US state courts.