We consider a large original equipment manufacturer (OEM) who relies on a contract manufacturer (CM) to produce her product. In addition to the OEM's product, the CM also produces for a smaller OEM. Both the larger OEM and the CM can purchase the component from the supplier, but their purchase prices may differ and remain unknown to each other. The main question we address is whether the larger OEM should retain component procurement by purchasing components from the supplier and reselling to the CM (buy–sell), or outsource component procurement by letting the CM purchase directly from the supplier (turnkey). We show that, under buy–sell, the larger OEM's optimal strategy is to resell components at the highest possible component purchase price of the CM (i.e., the street price). By comparing buy–sell and turnkey, we find that a CM with low component price is better off under turnkey, even though under buy–sell he receives more profits through the products sold to the smaller OEM. Furthermore, the larger OEM's preference between buy–sell and turnkey depends on her component price, the volatility of the CM's component price and substitutability between the two products.