Dairy Crest will pick up Arla's Express Dairies business, which includes depots in Nottingham and Liverpool, for £33m.
Arla decided to dump the milk delivery business because of falling profits and a 14 per cent drop in the home delivery market's share of liquid milk sales since 2000.
The move sees Dairy Crest become the largest doorstep milk supplier in Britain, and some believe the deal may save the country's remaining 9,500 milkmen from oblivion.
The group said it was confident of at least stopping the rot. It said it "has the industry-leading business model for doorstep and middle ground, which has delivered good profits and cash in recent years".
There were others in the dairy industry who also believed their was a future in the milkman, despite ruthless competition from cheaper, plastic cartons now available in all supermarkets and convenience stores.
Jim Begg, director general of trade association Dairy UK, told DairyReporter.com: "The market has been declining by around 10 per cent per year, but less so more recently. I detect almost a new interest in the whole concept of doorstep deliveries."
Dairy Crest shares have soared to their highest price for more than two years over the last couple of months. They stood at 550p midday Tuesday.
For more on this story, see DairyReporter's more in-depth article on the future of the British milkman. Dairy Crest deal offers hope for the British milkman