The brewery, which was founded in 1992 and employs 150 people, had revealed in April that it was exploring a sale or merger as a way of attracting new investment.
National law firm Freeths advised Breal Capital on the acquisition.
Freeths’ restructuring partner, John Jeffreys, said: “We are extremely pleased to have supported our client Breal Capital in this acquisition which represents an important addition to its existing portfolio.
“The future of this well-loved brewery has been secured with Breal’s support and we wish them every success.”
A spokesman for Black Sheep Brewery told the BBC: “This marks the next chapter in the history of Black Sheep as we look to grow the business in a sustainable way.
“Our team will continue to produce great beers from our landmark brewery in Masham.”
The award-winning brewery was founded by Paul Theakston to champion independent brewing following the sale of T&R Theakstons to a national brewer.
In 2003 Simon Theakston and his brothers led a buy back, bringing the brewery back into family control.
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