Darren Bent insisted he had to leave Aston Villa after too many "slaps in the face".
Brighton defender Greg Halford has agreed to extend his loan deal from Nottingham Forest until the New Year.
The 35-year-old Hungary international was released by Albion at the end of last season after his contract expired, bringing an end to his second spell with the club.
Gera had also played at The Hawthorns between 2004 and 2008, before linking up with Fulham for the next three years.
He revealed earlier in the summer that he had received a number of offers from the Championship to extend his time in England, but he has now decided to return to Hungary.
Gera played for Ferencvaros earier in his career, turning out for the cub from 2000 to 2004.