"We've made this move because currently, quite often, a customer's product choice is already made for them before they enter a liquor store," Davidson said. "This is because of producer dominance in the retail channel, which can result in the de-stocking or blocking of some brands and product portfolios. We've experienced this first hand - it's anti-competitive and should be challenged."
He said the acquisition would help "level the playing field" and was similar to another initiative launched by the firm aimed at overcoming "competitive barriers" - its entry into the tap beer market in 2011, which was previously dominated by local brewing giants Lion and DB Breweries.
Lion owns the Liquor King chain of bottle stores.
Independent brews international beer brands such as Carlsberg and Kingfisher under licence, as well as its own Boundary Road beer range, but is best known for pioneering the development of Australasia's RTD market.
Jeremy Livingston, who will be leading The Mill business as chief executive, said the sale agreement brought the possibility of a major face-lift for the firm's stores.
"Part of our future plan is to refurbish the chain so as to lift retail standards and improve the shopping experience," said Livingston. "We are also looking at franchising the store network, which will provide local operators with the opportunity to develop their own stores under a strong national brand. This model will put money back into the store's local community through jobs and local investment, and is similar to many established retail models."
Livingston said The Mill would be run as a standalone business, separate from Independent.
"Essentially, it will be business as usual at The Mill, but over time customers will notice that there are more brands and products available to them," he said.
The Mill is owned by New Plymouth-based Christopher and Nyall Simkin, according to the Companies Office.
Its website says the firm opened its first store in Taranaki in 1993 and the business had been successful as a result of low overheads and reduced prices.