First Milk has given itself a massive financial shot in the arm by cashing in more than a third of its shares in Robert Wiseman.

The co-op sold 4.17 million Wiseman shares last week for £18.8m, netting an £8m profit for the farmer-owned company. It now owns a 10% stake in the milk processor. The funds would be used to invest in its cheese brands and processing facilities such as Campbeltown, as well as to reduce First Milk's external borrowings, said a spokesman.

Earlier this month, new First Milk chairman Bill Mustoe wrote in the members' newsletter of the urgent need for investment in the cheese side. "The main thing we must focus on is the lack of profitability in our cheese business. This needs to be addressed quickly."

First Milk had no plans to dispose of any of its remaining shareholding in Wiseman, said chief executive Peter Humphreys.