You can't stop Ryan Seacrest, you can only hope to contain him.

Comcast Entertainment Group has inked a new multi-year agreement that will expand the American Idol host's television and new media business across the rest of the E! parent company's family of networks via his Ryan Seacrest Productions.

The deal will keep Seacrest on E! Entertainment Television into 2012, as he'll continue to serve as managing editor and anchor of E! News Live and as executive producer and host of the network's live red carpet specials. 

"Ryan is not only a spectacular broadcaster and producer but he is also the ideal ambassador for the E! brand," said Comcast Entertainment Group CEO Ted Harbert. "It is a personal and professional thrill to be the beneficiary of Ryan's incredible work ethic, flawless on-air skills and fantastic instincts as a producer."

While Seacrest's previous deal with Comcast Entertainment Group -- which he inked in January 2006 -- only applied to E! and The Style Network, the new pact also encompasses the company's G4, Versus, Golf Channel, Exercise TV, FEARnet, Comcast Sportsnet and PBS Kids Sprout networks. 

In addition, it also includes a new advertising relationship between E! and Seacrest's radio properties, such as American Top 40 and On-Air with Ryan Seacrest.

"Comcast Entertainment Group is the perfect engine to help drive Ryan Seacrest Productions to the next level in its evolution," said Seacrest.

"My experience with E! has been a perfect fit from the very start, and I am thrilled to continue working with them on the air, as well as developing and producing programming across all Comcast networks."

Ryan Seacrest Productions currently produces E!'s Keeping Up with the Kardashians and Denise Richards: It's Complicated for E!, as well as the upcoming Bromance for MTV and Momma's Boy for NBC.