Logistics company Gist had handled distribution from Budgens' depot in Wellingborough, Northamptonshire, for the past seven years but Musgrave is moving operations in-house following a strategic review.
The wholesaler is now consulting with 400 staff at the site, all of whom will be eligible to transfer over to Musgrave. The process is set to be completed by the end of this month.
The news follows a pledge by Musgrave earlier this year to plough £33m into providing the "best supply chain in Great Britain, bar none" for Budgens, including £10.5m to double capacity at the Wellingborough depot.
A Musgrave spokeswoman said the move would align Wellingborough with depots in Andover, Thamesmead and South Elmsall, which serve its Londis franchise business. Distribution at those sites is already handled in-house.