TV’s missing-persons report goes beyond Laurence Fishburne

Prime-time stars — they’re dropping like corpses on “CSI.”

Word leaked late Tuesday that Laurence Fishburne will leave CBS’ “CSI: Crime Scene Investigation” after just 2½ seasons as Dr. Raymond Langston.

CBS hasn’t picked a replacement yet, but with Ashton Kutcher substituting for Charlie Sheen on “Two and a Half Men,” CBS will start the 2011-12 season with new leads on at least two of its signature series.

Meanwhile, the exit of Christopher Meloni as a detective on NBC’s “Law & Order: SVU” has thrown that show into disarray, with Mariska Hargitay signed on for a reduced role and executives in an 11th-hour scramble to make a deal with costar Ice-T. And Lisa Edelstein, who plays Hugh Laurie’s boss Cuddy on Fox’s medical drama “House,” is also jumping ship; like Meloni, she reportedly couldn’t come to terms on a new contract.

In Fishburne’s case, it’s unclear why he’s leaving his role as the pathologist who replaced Gil Grissom (William Petersen) as the show’s focal character.

“Not sure why he chose not to return but he did,” Alan Nierob, Fishburne’s publicist, wrote in an email. CBS declined to comment.

A breakdown in contract talks would seem a likely culprit. At one time, “CSI” was TV’s No. 1 show — a peak of 26.6 million viewers watched during the 2004-05 season. But the 2010-11 season was the least-watched ever, with an average of just 13.7 million total viewers, according to the Nielsen Co. Many “CSI” fans were vocal about preferring the edgy, sarcastic Petersen to the more enigmatic Fishburne.

As a drama entering its 12th season, “CSI” is saddled with growing costs — the cast and crew typically earn raises as a show continues — and due to falling ratings the series is earning much less in advertising revenue than it previously did. So the producers have less room to accommodate a pricey star such as the Oscar-nominated Fishburne.

Although the news came suddenly, CBS seemed to be preparing for a possible Fishburne departure. The writers have been toiling away on story lines for next season that do not feature his character, according to a writers’ representative who spoke on condition of anonymity. The network also last month announced it would downgrade “CSI” from its traditional Thursday showcase.

“The fact that the show was sent to Wednesdays at 10 makes me think that there was knowledge of [Fishburne’s] imminent departure,” said ShariAnne Brill, a longtime media analyst.

Even so, the network has no time for a long casting process: Filming is scheduled to begin for “CSI’s” 12th season next month.

scott.collins@latimes.com