Bayer has told U.S. lawmakers it could stop selling the popular Roundup weedkiller unless they can strengthen legal protection against product liability litigation, according to a financial analyst and a person close to the matter. Bayer has paid about $10 billion to settle disputed claims that Roundup, based on the glyphosate herbicide, causes cancer. About 67,000 further cases are pending for which the group has set aside $5.9 billion in legal provisions.