German pharmaceutical giant Bayer says it will cut 12,000 jobs globally due to issues from its takeover of Monsanto.

Bayer's shares were smashed when a US jury awarded $US289 million ($396 million) in damages to a former school groundskeeper whose terminal cancer was linked to its pesticide product Roundup - a product made by Monsanto.

With thousands of other patients lining up to make similar claims, Bayer says it has to cut one in 10 workers, mostly in Germany, and sell its animal health division for up to 7 billion Euros (AU$11 billion).

It will also sell its Coppertone Sunscreen and Dr Scholl's foot care brands.

Werner Baumann, Chairman of the Board of Management, said these are necessary steps to ensure the business is sustainable.

“We have made very good progress with Bayer's strategic development in recent years,” he said.

“As we now proceed with these measures, we are laying the foundation to sustainably enhance Bayer’s performance and profitability.

“With these measures, we are positioning Bayer optimally for the future as a life science company.”