ET has the latest...

ET confirms that after eight seasons, William Petersen is leaving the hit CBS drama "CSI," but sources tell ET this does not signal the end of the series, which continues to be one of the top rated shows on CBS.

The actor, who plays detective Gil Grissom, will exit the show at midseason, with the 10th episode of the upcoming season being his last as a regular cast member.

"For me, it's a really good situation," Petersen tells Entertainment Weekly who first reported the story. "I don't want the audience to think it's NOT... [It isn't] like there's something going on, like 'Petersen's unhappy,' 'cause it's not true. It's quite the contrary. "

Meanwhile, executive producer Carol Mendelsohn tells EW he may just be back. "He will remain throughout the run of the series an executive producer," she says. "He will, whenever CBS asks, come back. I don't think you've seen the last of Gil Grissom."