This thesis presents an in-depth case study of a Malaysian public utility company expected by the government to transform itself into a self-financing, efficient and profitable organisation during corporatisation. As profitability became increasingly important, attempts to enhance profitability were made through imposing new accounting rules and recruiting new accounting graduates. In spite of these attempts, the finding reveals that accounting changes were enacted, but over time became separated from, or loosely coupled with, other intraorganisational concerns. An explanatory case study method, using mainly semistructured interviews and document reviews, was adopted. The framework for understanding the process of implementing accounting change, the context in which change unfolded and the emerging consequences of change is based on the combined insights of New Institutional Sociology (Meyer and Rowan, 1977) and Old Institutional Economics (Bums and Scapens, 2000). As sensitising devices, these institutional theories are useful, but alone are not able to fully incorporate the idiosyncrasies of the case findings. Subsequently, the research aims to develop a theoretical framework to understand the processes through which accounting systems can become loosely coupled by incorporating the insights drawn from the two institutional theories as well as the idiosyncrasies of the case. In this framework loose coupling is conceptualised as an evolutionary process shaped by existing internal institutions, the beliefs and norms in the environment, and the interests and power of organisational actors. Issues of the intertwined relationship between efficiency and institutional pressures, the balancing act between public service and profitability concerns, and the inter-play of resistance, trust and power are included. The theoretical framework enriches our understanding of why the role of accounting took its present form and why accounting change was enacted, but continued to (re )embed the existing public service values and norms within the case organisation. It is able to capture the complexity of the ongoing process of accounting change during which the ingrained public service values and practices remained stable in spite of corporatisation.