EXCLUSIVE

Gabriel Aubry was officially told today what we already reported ... he will NOT face criminal charges for the Thanksgiving Day fight with Halle Berry's fiance.

Instead, the L.A. City Attorney's Office has decided to hold an informal hearing with Gabriel to discuss his brawl with Olivier Martinez.

TMZ broke the story ... Halle, Olivier and Gabriel's attorneys all agreed to settle the matter and avoid a messy criminal trial.

As we told you, investigators believe Gabriel was actually the aggressor ... despite getting his face bruised and bloodied during the the fight.

Gabriel could end up getting anger management classes after the City Attorney hearing -- or simply told not to do this again.

No date's been set for the hearing.