SHANGHAI, Sept 7 (Reuters) - China Evergrande’s Shenzhen-traded 5.9% May 2023 bond fell more than 20% in afternoon trade on Tuesday, extending falls since a ratings downgrade made the company’s bonds ineligible for use as collateral in repo transactions. A Shenzhen-traded 6.98% January 2023 bond fell more than 15% and the company’s Shanghai-traded 6.98% July 2022 bond fell more than 9%. (Reporting by Andrew Galbraith; Editing by Christian Schmollinger) Our Standards: The Thomson Reuters Trust Principles.