Pre-existence of a national trademark
If you have a previous national trademark identical to what you would like to protect, you can claim its pre-existence. This will allow you to preserve your previous rights, even when renouncing the national trademark or failing to renew it.
Sale or concession of a license
You can decide to cede the trademark to third parties by requesting the registration of said transfer in the trademark register of the European Union. As an alternative, you can grant a license for a European Union trademark for individual countries or limited geographical areas. Transfers and licences may be partial, that is, regard only some products or services for which the trademark is registered.