BEIJING, July 21 (Reuters) - China will issue 750,000 metric tons in sliding tariff rate cotton import quotas to non-state-run firms, according to a document released by state planner the National Development and Reform Commission (NDRC) on Friday.

The document, which calls on eligible traders to apply for a share of the import quota, does not specify when the quotas will be issued. (Reporting by Andrew Hayley; Editing by Jan Harvey)