It announced it had bought Arla's Express Dairies Depot operations for £33m this week, including two dairies, 77 small distribution depots and approximately 390 million litres of milk per annum.
The move is expected to generate substantial operational and financial savings by combining both company's declining doorstep business.
It will not mark the end of one of the UK's household names - Express Dairies - as DC is still reviewing the brand name, which is strong in the north of the country. But it heralds Arla's exit from the middle-ground market.
The doorstep sector, which has seen volumes fall from 2.5m litres a day to half a million over the last decade, will now be dominated by Dairy Crest and the farmer co-operative Dairy Farmers of Britain.
Despite the market's sustained decline, both companies have a strong belief that they can turn around the ailing sector.
The deal will marginally strengthen the industry's arm in trading in the competitive middle-ground sector. But the number of sellers into the sector will minimise the impact on prices and consumers.
The deal must now be cleared by competition watchdogs at the OFT, who recently raised questions over Robert Wiseman's attempted purchase of the small liquid milk assets of Scottish Milk Dairies.
But a Dairy Crest spokesman was optimistic the deal would be approved without having to sell off any delivery rounds for competition reasons.
Milk supplies will be transferred over a two-year period in order to reduce the immediate impact on supplying farmers.