This paper discusses the aggregate production-distribution problem for a manufacturer of plastic products that are produced using injection moulding. For each product, only a single mould is available, but by exchanging moulds between plants, it is possible to produce any product at any plant. This mould sharing offers opportunities for cost savings but complicates the aggregate production-distribution planning. We present mixed integer linear programming formulations for this planning problem, and a matheuristic solution approach based on these models. The main goal of this aggregate planning tool is to quantify the opportunities that mould sharing offers to the plastics manufacturer. Computational experiments based on a real-life dataset confirm that mould sharing can reduce the production-distribution total cost with about 10%, and that the suggested matheuristic is capable of generating solutions that capture most of this significant savings potential. © 2013 Elsevier B.V.