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.