Aug 20 (Reuters) - Australian miner South32 Ltd reported an 80.5% slump in full-year underlying profit on Thursday, as prices and demand for its key products were battered by the Sino-U.S. trade war and the COVID-19 pandemic.

The world's biggest producer of manganese said underlying net profit was $193 million for the year ended June 30, compared with $992 million a year earlier.

It announced a final dividend of 1 cent per share, down from 2.8 cents last year. (Reporting by Shashwat Awasthi and Shruti Sonal in Bengaluru; Editing by Devika Syamnath)