The Tenterden-based business has added 388 acres to its land in Kent, after outbidding a French wine house to secure the lease on sites near Boxley on the North Downs.
This leaves Chapel Down with sites amassing more than 950 acres in total. This latest deal is expected to be confirmed after a legal process on or before October 11.
Frazer Thompson, chief executive, said: “We believe this area of the North Downs offers the finest terroir [soil] in England for sparkling varieties and successive excellent crops and critical acclaim for wines from our Kits Coty vineyard prove it.
“This will be the largest vineyard in England with the potential to produce up to a million bottles of sparkling wine per annum when mature.
“The sites will be planted over the coming years to enable us to grow our business to satisfy the increasing demand for Chapel Down wines over the next 25 years.”
It has not been disclosed how much the deal, announced last week, was worth.