Realtime Worlds has sold its Project MyWorld to an "anonymous" American company, according to a Develop report.
It's not yet known if the 23 staff who were working on the game will lose their jobs, or if they will continue to work on the project.
Realtime Worlds' other title, APB, is still up for sale. The $100 million game is reported to have 130,000 registered users, spending an average of $28 per month.
Dundee's Realtime Worlds went into administration last month.
The company then re-employed 23 of its staff to enable MyWorld to be completed.