Comcast Corp struck a deal to buy a majority stake in NBC Universal from General Electric Co, creating a media superpower that would control not just how TV shows and movies are made, but how they are delivered to the home.

The deal has been discussed for months and brought to light deep divisions within the media business over its future, with some lauding Comcast Chief Executive Officer Brian Roberts as a visionary and others calling it the most foolhardy acquisition since AOL bought Time Warner Inc in 2001.

In a world where the Internet has disrupted traditional media, Comcast -- the largest U.S. cable service provider -- wants NBC Universal so it can have programing it can deliver to audiences however they may want it, whether through TV sets, personal computers, or mobile devices.

Critics, including some of Comcast's own shareholders, suggest there is too little overlap between the businesses to draw out meaningful savings, and that competition regulators are bound to burden it with restrictions.

Moreover, big media deals rarely work, they add, pointing to Time Warner Inc's breakup for example. Once the world's biggest media company, Time Warner has spun off Time Warner Cable Inc and will soon do the same with AOL.

There's no question that you really have a great little test tube here because you have one large company that said this is absolutely not the thing to, said veteran media dealmaker Barry Diller, CEO of IAC/InterActive Corp.

And you have another company that said it's exactly the thing to do, he told the Reuters Media Summit. So it's going to be an interesting comparison over time.

The deal calls for Comcast to contribute $6.5 billion in cash, its own cable TV networks and other assets in return for a 51 percent stake in NBC Universal, which owns TV networks, a movie studio, theme parks and local TV stations. GE will keep a 49 percent stake.

The companies said in a statement on Thursday that NBC Universal's businesses have been valued at $30 billion. The Comcast businesses that will be part of the deal -- including E!, Versus, the Golf Channel and 10 regional sports networks -- are valued at $7.25 billion

GE cleared the way for the deal by securing Vivendi SA's agreement to sell the company its 20 percent stake in NBC Universal for $5.8 billion.

For GE, the deal allows it to concentrate on its industrial business, and could be the first step in a full break with NBC Universal, ending a relationship that stretches back to the dawn of television. Included in the terms of the transaction is a provision that allows GE to begin an exit from the joint venture after 3 1/2 years.

As part of the deal, NBCU will borrow about $9.1 billion from third-party lenders and distribute the cash to GE. Current NBC Universal Chief Executive Jeff Zucker will lead the new venture.

(Reporting by Paul Thomasch and Yinka Adegoke, editing by Tiffany Wu and Lisa Von Ahn)