Rancic, 40, whose final episode is set to air on August 10, will continue to co-host the network's "E!'s Live From the Red Carpet" and "Fashion Police", said The Hollywood Reporter.
"For more than a decade, I was fortunate enough to play a role in the success of 'E! News' and will miss my family at the show.
"At the same time, I am excited to not only continue as host of two major franchises on E! but also executive produce the aspirational new show Rich in Faith for Oxygen as well as take my wine and clothing lines to the next level," Rancic said in a statement.