Andrew Kay, managing director of the McLaren Vale-based producer, said the fit between Gonzalez Byass and Wirra Wirra seemed a natural one.
“As an independent producer we place great emphasis on our history, sense of place and family," he said.
“Gonzalez Byass shares like-minded philosophies and we believe our range of super-premium Australian wines will complement its offering.
“We have invested significantly in grape and wine quality over the past few years and the results are being seen in the glass.
"Now is the time for us to move to the next phase of our brand development in the UK.”
GBUK managing director Martin Skelton added: “This is a fantastic development for our company.
“We have been very successful at developing our own premium wine and sherry business in recent years, as well as building a portfolio of high quality agency brands including Quinta do Noval, Jackson Estate, Matarromera and Fillaboa.”