A £150 million fresh milk dairy is being built in Aylesbury in Buckinghamshire, which will provide up to 1,000 construction jobs over the next 18 months.
Arla Foods has appointed Caddick Construction Limited (CCL) and NG Bailey to carry out the work, following a six-month tender process.
NG Bailey will be responsible for the installation of the mechanical and electrical works, as well as wastewater and effluent treatment and recycling.
Jakob Nielsen, project director at Arla, believes the two firms will do an excellent job.
"Throughout the tender process they both demonstrated a good understanding of our building and environmental requirements," he said.
Chief executive officer Peter Lauritzen added: "In addition to it being one of the largest construction projects in the UK, we have ambitions for it to be the world's first zero carbon fresh milk dairy."
Once built, 700 workers at the dairy will process and package up to one billion litres of milk per year.