The plants are located at Aberystwyth, Bangor, Newtown and Wrexham.
All existing operations, assets and staff at each of the four plants have been transferred to the new owner.
Tudor Griffiths, managing director of the Shropshire-based Tudor Griffiths Group said: “We are very enthusiastic about the prospects for these four plants and the benefits they will bring to our Group’s portfolio.
“The purchase greatly enhances our existing readymix operations within the area.”
The four batching plants add to the existing Tudor Griffiths network of eight readymix outlets meaning virtually any location within the whole of North & Mid Wales, Cheshire and North Shropshire is within 20 miles of a TG Concrete Plant.