New York (CNN Business) Disney's $71 billion deal to buy most of 21st Century Fox will take effect on Wednesday, March 20, the companies said Tuesday morning.

It will be an epochal event in the entertainment business — the merging of two movie studios and the end of Fox as we all knew it.

Staffers at the 20th Century Fox studio are bracing for layoffs and other big changes.

Disney DIS is picking up the studio, a controlling stake in Hulu, a suite of entertainment channels like FX and Nat Geo, and other assets.

21st Century Fox FOX The remaining parts ofwill be spun off into a new company simply known as Fox. It will include the Fox broadcast network, Fox News and Fox Sports.

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