A2 Corporation is taking direct control of the marketing and sales of its products in Britain and Europe.
The speciality milk products company announced the change at its annual shareholders meeting on Tuesday.
The move means A2 will buy the Muller Wiseman Dairies' (MWD) 50% shareholding in the British business for what it calls a nominal amount, while MWD will supply product to the company on a cost-plus basis.
A2 will invest $5 million over the 2014 financial year into the British business, where its products are sold in five of the major chains, including Tescos and Waitrose.
A2 managing director Geoffrey Babidge said the re-shape aimed to drive growth at a faster pace.
"Where we sit 10 months after launch is that we'd like to be a little bit further progressed with slightly broader distribution than we have at this point in time," he said.
"This change in the structure of the joint venture will enable us to put additional resources to focus on achieving that increased depth and distribution."
A2 had appointed experienced sales people in Britain to build on the growth already achieved, Mr Babidge said.
The company also planned to launch into the North American market but Mr Babidge would not give a timeframe for that.