(Sharecast News) - Shares in German chemicals maker Bayer surged on Friday after a US appeals court said it was protected under federal law which would limit liability from claims that its Roundup weed killer causes cancer.

The case was brought by David Schaffner, a Pennsylvania landscaper diagnosed with non-Hodgkins lymphoma in 2006, who claimed the Bayer had failed to provide a cancer warning on the label of Roundup.

However, the US Circuit Court of Appeals in Philadelphia ruled that the Federal Insecticide, Fungicide, and Rodenticide Act required nationwide uniformity in pesticide labels, and stopped Pennsylvania from adding a cancer warning.

Bayer settled a large portion of the Roundup litigation for $11bn in 2020, but still faces around 58,000 unresolved claims.

Reporting by Frank Prenesti for Sharecast.com