The American-owned drinks giant has signed a letter of intent to acquire the business, and completion should take place by the end of November.
The move is part of Constellation’s plan to expand its South African offering beyond its existing, entry-level brand Kumala and into the premium tier.
As part of the deal, Flagstone viticulturalist and winemaker Bruce Jack will be employed by Constellation. In his new role, Jack will supervise all of Constellation’s viticulture and winemaking in South Africa, including Kumala.
Constellation Europe’s president Troy Christensen said: “The proposed purchase of such a high-profile South African winemaking company and its dynamic portfolio of wines will mean that we have a credible premium-orientated portfolio to spearhead the development of South African wine in the UK and across Europe.
“Flagstone will help to take the South African category to another level of success by providing an incentive for the wine trade to premiumise their wine business and by encouraging more shoppers to trade up to better quality more often.”