Fantha Tracks reports that the business name for producing Episode IX is Carbonado Industries (UK) Ltd. The working title of the film will be Black Diamond, they say. (Both terms refer to the same substance.)
The article also contains a short history of the recent production companies and working titles, many of which were uncovered by the same folks when they were with Jedi News.
Episode IX, which will be directed by The Force Awakens’ J.J. Abrams, is due in December 2019. Other reports says that the returning crew also includes visual effects supervisor Roger Guyett and costume designer Michael Kaplan (who also stayed on for The Last Jedi.)