FRANKFURT -(Dow Jones)- Media conglomerate Bertelsmann AG said Tuesday that Gerhard Zeiler, the chief executive of its broadcasting unit RTL Group SA (RTL.BT), will leave the company April 18 at his own request. Zeiler, who is also a member of Bertelsmann's executive board, is leaving "by mutual and amicable consent to devote himself to new professional challenges," the company said in a statement. It said RTL will be led by Guillaume de Posch and Anke Schaeferkordt in the future. Zeiler has been CEO of RTL Group since March 2003 and joined Bertelsmann's executive board in 2005. Bertelsmann said Schaeferkordt, who leads RTL's operations in Germany, will take Zeiler's place on the executive board. De Posch is a former chief executive of rival broadcaster ProSiebenSat.1 Media AG (PSM.XE) and was recently appointed to RTL Group's senior management. -By Philipp Grontzki, Dow Jones Newswires; +49 69 29 725 107; philipp.grontzki@dowjones.com