The impact of post-merger integration on the customer–supplier relationship

•Post-M&A integration actions influence purchase behaviour through their impact on critical customer relationship variables.•Impacts on service performance, customer orientation, account management and product breadth were particularly important.•The role of competitor reaction was also highlighted.•Findings help illuminate precise mechanisms through which M&A affects customers and the merging firms’ market performance.

While the impact of mergers and acquisitions (M&A) on internal stakeholders has generated considerable empirical study, comparatively little academic attention has been paid as to how external stakeholders such as customers are affected by, and respond to, M&A activity. This study adopts case-study methodology to illuminate how the customer–supplier relationship is affected by post-merger integration processes in the business-to-business context, with the aim of increasing our understanding of why customers respond to M&A in the ways that they do. The findings highlight the importance of a set of critical customer relationship variables through which post-M&A integration actions can influence customers' perceptions of the merged organisation and, ultimately, their purchase decisions. We also identify a set of specific individual integration actions that appear to trigger changes in the critical customer relationship variables. Together, the findings contribute to our understanding of the precise mechanisms through which M&A can affect customers' purchase decisions and the combining firms' market-related performance. More broadly, consistent with the stakeholder perspective, they reinforce the need to take account of external as well as internal stakeholders when considering the drivers of M&A outcome. Implications are discussed for future research as well as for B2B service industry executives involved in M&A.