Moretti took over the festival in its 25th edition in 2007 and remained at the helm in 2008.
Alberto Barbera, President of Turin's Cinema Museum and Steve Della Casa who is President of the Turin Piedmont Film commission confirmed the news. Both are members of the board of directors of the Northern Italian festival.
'We knew it was short term contract and we hoped, considering his success, he could have stayed another year but he decided to make a film and wants to shoot it in the autumn of 2009 which overlaps with the festival dates.
'We are sad to see him go, and I think he is too, but the experience (of Moretti at the head) helped relaunch the festival. In two years we saw 127% increase in attendees, which was obviously economically helpful but he also gave us renewed visibility. What he gave the festival has been of real value,' Barbera told ScreenDaily.
In a statement Moretti said 'I was happy to have had this opportunity and I dedicated myself to it wholeheartedly. Next year I will make a new film and I can not guarantee the same attention to the work (of the festival)...I am leaving a festival that is unique in the Italian panorama, that can grow as it continues to support good authorial independent cinema.'
No details are available for the new project of the Palm d'Or winner, which Della Casa said is currently being written.
Turin is one of the most active regions for film-making in Italy and boasts a strong film commission, prestigious Cinema Museum and regional film funds.
Moretti was sought out when a strong personality was needed to lead the twenty-five year old event after the festival was seen as threatened in 2006 with the launch of the high-profile, glamorous and well-funded International Rome Film Festival that landed itself between Venice and Turin.
Moretti led two strong editions with support from international figures like Toronto Festival co-director and TIFFG CEO Piers Handling, who presided over the jury in 2007.
With the 2008 edition Moretti attracted reclusive film-maker Roman Polanski to present the retrospective of his work and opened the festival with Oliver Stone
presenting his film W., a picture that was first expected to have its Italian launch in the International Rome Film Festival.
Barbera said they would take their time to find the right match for Turin's 2009 edition.