Insurance services have a prominent role in modem societies. Empirical evaluation of market interactions in insurance is, however, scarce. To fill this gap, two models are proposed. Each captures the main features of either regulated or deregulated markets. Three levels of decisions (reinsurance, sales effort and prices) generate testable predictions on firm behaviour with respect to sales effort choices. Recent evolution of the Portuguese market provides a natural data set for application. Estimation before and after price deregulation reveals a noticeable change in behaviour. Coordination has characterized the interaction under price regulation. Competition between firms has increased after deregulation.