Proximo Spirits has announced a majority stake acquisition in Proper No. Twelve Irish Whiskey, which was co-founded by MMA superstar Conor McGregor.

McGregor will retain an interest in Proper No. Twelve, and will remain actively engaged in the promotion of the brand, according to a release from the company, along with the other co-founders.

“I founded Proper No. Twelve less than three years ago and today it has become a shining star in the spirits industry,” McGregor says. “This agreement is exciting for my partners and me, and the potential is limitless! Our vision is for Proper No. Twelve to continue its incredible growth worldwide and to keep bringing new consumers to the now-reinvigorated Irish whiskey market.”

Proximo previously owned a 49% stake in the brand. In obtaining a majority share, the company reportedly paid $600 million to McGregor and his two co-founders, his manager and business partner Audie Attar, and spirits industry entrepreneur Ken Austin

The brand has grown dramatically in a short time. Its Instagram, @properwhiskey, is among the most followed social media accounts in the spirits industry.

“Conor McGregor, Proximo and our partners have taken the spirits world by storm,” says Mike Keyes, president and CEO of Proximo. “When we launched, the Irish whiskey market was dominated by one brand. Now, Proper No. Twelve has disrupted the category and has become a leading brand in the industry. We are thrilled with what we and our partners have achieved in growing Proper No. Twelve to this point, and we look forward to continued success together. This agreement also demonstrates Proximo’s commitment to expand its presence in the fastest-growing segments of the spirits industry.”

The brand has shipped more than 500,000 nine-liter cases (over six million bottles) in eight distinct international markets in the first two and a half years of business, the company says, with additional territories on the horizon.

“Conor and I started to dream about building our own brands and companies from the beginning of our journey together, which was roughly a decade ago. We brought that dream to reality,” says Attar, CEO of Paradigm Sports, and co-founder of the brand. “We could not be prouder of our team and the success we’ve all built together. We are excited for the next phase of this incredible brand: making Proper No. Twelve the leading Irish whiskey in the world.”