The US cablenet announced Thursday it had secured over 75% of shares in the London-based broadcaster.
This includes the 39.1% owned by 21st Century Fox, which it will purchase for a consideration of £11.63 billion.
Its bought 672.8 million Sky shares from Fox at £17.28 each.
After it lost to Comcast in the auction for Sky, Fox said it would withdraw from the company.
The £30 billion takeover is expected to be finalised on October 10.