Comcast shares jumped 21% on plans to split.

The tax-free spinoff separates NBCUniversal and Sky from Comcast’s broadband and wireless business, reversing the cable-conglomerate bundling of the past decade.

Comcast retains a 19.9% stake in NBCUniversal for up to a year pending regulatory approval of the split.

Sources: Aol, New York Post, Yahoo! Finance