Bayer AG, the German drug and chemical company that owns the herbicide Roundup, denied rumors first published by Bloomberg News that it had proposed paying between $6 billion and $8 billion to settle more than 18,000 claims that allege its product causes cancer. In an email to Reuters, the company clarified its position on a potential payout sum. “Such a statement is pure fiction,” chief mediator Kenneth Feinberg said. “Compensation has not even been discussed in the global mediation discussions.” Feinberg has successfully negotiated settlements for the victims of the Sept. 11 terror attacks and Bernie Madoff , as well as overseeing the BP oil spill fund. A group representing the claimants had originally asked for more than $10 billion to drop the lawsuits already in progress and to settle claims brought by anyone who has not yet been diagnosed. Shares in Bayer surged more than 11 percent on Friday in Frankfurt on news of a potential settlement, though still fall short of their price 14 months ago when Bayer bought Roundup for $63 billion from Monsanto.

Editor’s note: This item was updated to reflect mediator Kenneth Feinberg’s response to Reuters.