This thesis pursued three objectives: (1) to identify policies and practices which are related to the retention of professionals and managers with critical skills; (2) to document why and how these policies and practices have changed in relation to the business strategy; and (3) to assess whether the organisation's skill supply patterns constitute a strategy, that is, explicit, consistent and coordinated efforts supporting the business strategy. Guided by a contextual theoretical framework and methodology, the researcher undertook a pilot stuay of two Canadian high technology firms, and followed with three case studies of large UK-based high technology organisations with an R&D Division. The findings indicated the importance of hard benefits (compensation) as a necessary condition for recruitment and retention, and the complementary impact of twelve soft benefits (job characteristics and other factors tied to the work, organisational and social environments) with special relevance for retention. Lifetime employment as a policy and as the dominant skills supply pattern proved to be resistant to change. The HRM context (comprising the history of the organisation, managerial and professional cultures, the personnel function, and workforce planning) was found to inhibit skill initiatives, but certain features became less negative over time. In particular, the cumulative effect of recruitment of new skills over several years altered the internal labour market such that many employees supported new ways of doing business. Skills were found to be solidly embedded in the work and social organisation, and high levels of energy were required to modify the organisation-wide skillbase. Both single lever and multiple lever SKISSs were identified. b1iddle managers proved to be potential key actors in obtaining skill advantages for the entire R&D Division. Top management paid attention to skill issues under extreme circumstances such as a shift from the public to private sector, and a change of mission. The thesis leads to a number of policy recommendations and avenues for future research.