FRANKFURT -- Shares in German farm chemicals, materials and drug company Bayer have plunged in the wake of a U.S. court verdict against Monsanto, which Bayer has acquired.

Shares of Leverkusen-based Bayer fell 11 per cent Monday in morning trading in Europe to 83.09 euros per share.

A jury in U.S. federal court in California delivered a $289 million verdict Friday on behalf of a former school groundskeeper who said that exposure to Monsanto's Roundup weed killer caused his non-Hodgkin's lymphoma, a form of cancer. Monsanto said government agencies and hundreds of studies have concluded Roundup is safe.

Bayer completed its takeover of Monsanto on June 7. It says it will no longer use the Monsanto name.