The star will still play the Caped Crusader and produce and wants to bring “focus, passion and the very best performance I can give.”
Affleck said on Monday he would not direct superhero project The Batman (working title) as he wanted to prioritise his performance.
Warner Bros said it stood by Affleck and it is understood the decision was mutual.
“There are certain characters who hold a special place in the hearts of millions,” Affleck said in a statement on Monday. “Performing this role demands focus, passion and the very best performance I can give. It has become clear that I cannot do both jobs to the level they require.
“Together with the studio, I have decided to find a partner in a director who will collaborate with me on this massive film. I am still in this, and we are making it, but we are currently looking for a director. I remain extremely committed to this project, and look forward to bringing this to life for fans around the world.”
Studio and star will now search for a new director. The film remains undated however it is a key part of the DC Entertainment pipeline.
Pre-production had been scheduled for the summer, although there has been talk of problems with the script that Affleck is writing with Geoff Johns.
The star directed crime noir Live By Night that opened recently but has only managed $10.3m at the box office after six weekends.
Affleck will next be seen as Batman in the November 17 release of Justice League. His first appearance in the role was in last year’s Batman v Superman: Dawn Of Justice.
Variety broke the story.