Sept 9 (Reuters) - "Fortnite" users will no longer be able to use Apple Inc's sign-in system to log in to the game as early as Friday, the video game maker said.

Apple and Epic Games have been in a legal battle since August, when the maker of the popular video game launched its own in-app payment system.

Apple's App Store requires developers to use Apple's payment system and pay a 30% commission.

The iPhone maker on Thursday filed counter claims against Epic, asking for lost App Store fees and other damages, and seeking an order to stop the game maker from operating its own in-app payment system.

(Reporting by Munsif Vengattil in Bengaluru; Editing by Shounak Dasgupta)