The deal sees Miller Homes acquire 19 live sites containing around 3,500 plots and a further five strategic sites.
The acquisition will see Miller enter the South West for the first time and expand its business in the Midlands and South regions.
Under previous owner Blackstone, St Modwen turned over £368m in latest published results for year-end 2022, making a pre-tax profit of just £5.3m, while Miller Homes, owned by US investor Apollo, achieved just over £1bn revenue generating a pre-tax profit of £162m.
Miller will continue to operate the business under the St. Modwen Homes brand, and will establish a new regional office in the South West of England.
Miller Homes CEO, Stewart Lynes, said: “We are committed to growth and playing an important part in addressing the housing shortage. We were attracted to the quality and location of St. Modwen Homes’ land, helping us grow and expand to new areas.
“Through operating St. Modwen Homes under its brand, we can continue to deliver choice to the market, while maintaining our commitments to quality, sustainability and the customer experience.”
The deal is subject to regulatory approval and is expected to close in the first quarter of 2025.