Aggregates group Ennstone says it has found a bidder for the loss-making engineering division of Johnston.

Aggregates group Ennstone has said that it has found a buyer willing to pay up to £30m for the engineering division of aggregates group Johnston.

Ennstone is in the process of acquiring the Johnston Group for £48.3m and wants to sell the loss-making engineering arm to reduce Johnston’s debts.

Ennstone’s plans to acquire Johnston's quarryies are in danger of being scuppered by a shareholder revolt at an extraordinary general meeting being held this Friday. North Atlantic Value, which owns 6.7% of Ennstone, has said that the acquisition exposes the company to unacceptable risks and could affect its value.

NAV is calling for a non-executive director to be appointed to the board and for a complete strategic review of the group aimed at finding a buyer.