The couple broke up weeks ago, according to sources, but Cox and Arquette have agreed to stay friends as they work together on the upcoming Scream sequel.
Ironically, they met on the set of the first Scream film in the mid-1990s.
A statement from the couple reads, "We have agreed to a trial separation that dates back for some time. The reason for this separation is to better understand ourselves and the qualities we need in a partner and for our marriage. We remain best friends and responsible parents to our daughter and we still love each other deeply.
"As we go through this process we are determined to use kindness and understanding to get through this together. We are comfortable with the boundaries that we have established for each other during this separation and we hope that our friends, family, fans and the media also show us respect, dignity, understanding and love at this time as well."
The couple has one child together, six-year-old Coco.