The thesis is concerned with the means by which labour is managed in the young, turbulent and high risk industry of North Sea oil extraction. To explain this, the study had to extend beyond the more usual focus of research attention, the inmediate relationship between employer and employee, to examine the wider commercial relationship between the major oil companies and their contractors from the perspective of both parties. The response of the trade unions is assessed in this broader context. In a relatively short period of time an industrial relations system of considerable complexity has developed. The spreading of financial risk by the operating companies (oil majors) is paralleled in industrial relations by the delegation of responsibility to contractors. As a result, a two tier workforce has developed. The study analyses the processes at work, drawing on a range of interview, observation and archival techniques. Collective bargaining has been widely used to cope with the labour problems posed by these extreme financial and environmental circumstances. It is demonstrated that this has sometimes been imposed upon the contractors and that it operates at both the mUlti-employer, industry level, and at that of the individual company. However, the thesis concludes that this collective bargaining rests more on loose, informal agreements, and trade union lobbying, rather than formal agreements and procedures.