The high cost of producing a long-running series was being blamed for the departure of Laurence Fishburne from CBS's Csi Crime Scene Investigation. Fishburne's exit after just 2 1/2 seasons was announced on Wednesday, but CBS has declined to comment on his departure and Fishburne's publicist, Alan Nierob told the Los Angeles Times that he was "not sure why he chose not to return but he did." The Times noted that while ratings for the onetime No. 1 television show have fallen, thereby reducing the rate CBS can charge advertisers, production costs have risen. "The cast and crew typically earn raises as a show continues," the Times observed, "so the producers have less room to accommodate a pricey star such as the Oscar-nominated Fishburne." Somewhat surprisingly, the network has not announced a replacement for the actor despite the fact that the series is due to start production on a new series in July.