We analyse how union structures that differ in the degree of wage‐setting centralisation affect the pattern of R&D network formation. Within the context of a three‐firm industry, a central union that sets a uniform wage is shown to induce a partial R&D network that includes two firms but excludes the third. In contrast, we find that, under less centralised union structures, firms have incentives to form R&D networks with a larger number of alliances. This result is consistent with the stylised facts for industrialised countries: recent decades have seen an upsurge in R&D alliances along with labour market deregulation towards more flexible wage‐setting institutions.