"Opportunities exist in both businesses to streamline supply chains and enhance our competitiveness. It gives us the ability to optimise how we process milk solids and get the most value from our supply of milk," he said.
Dairyworks will operate as a stand-alone business under the Synlait umbrella, with its chief executive Tim Carter, reporting to Clement.
The company was established in 2001 in South Canterbury and is one of the larger companies operating in New Zealand's everyday dairy category.
Dairyworks is now based in Christchurch, where it supplies New Zealand with almost half of its cheese, a quarter of the country's butter, as well as milk powder and the Deep South icecream.
It owns the cheese and butter consumer brands Dairyworks, Rolling Meadow and Alpine which are supplied to supermarkets in New Zealand and Australia.
A2 Milk is Synlait's second biggest shareholder after Bright Dairy, with 17.4 per cent.
Dairyworks was established in 2001.