Actor had said he would only participate if Greengrass directed.
Greengrass wanted to push the film back a year and a half, moving it to 2012, but the studio was unwilling to wait, according to individuals in the studio camp.
Whether the project gets done now at all hinges on star Matt Damon.
Previously, Damon had said that he would be involved if Greengrass — who directed him in "The Bourne Supremacy" and "The Bourne Ultimatum" — was involved. (The first film in the series, "The Bourne Identity," was directed by Doug Liman.)
Now it’s an open question as to whether Damon will participate.
According to blog The Playlist, Greengrass left the film last week over an issue with who’s writing the script. Citing friends and sources close to the project, the blog said there were two scripts, one by "Ultimatum" co-writer George Nolfi, who is now working with Damon on "The Adjustment Bureau," another by hot scribe Josh Zetumer (Peter Berg‘s "Dune"), who was hired by Universal without consulting Greengrass.
Meanwhile, Greengrass has been tinkering with "Green Zone" on Universal’s dime. The budget on that film, which was going to be a "smaller" film than the "Bourne" pictures, initially was said to be about $100 million, but recent reports put it closer to $150 million.