The incident occurred in August 2006 when a module was being installed on a platform sub-structure. During the procedure to lift the module into place a worker’s leg became trapped between the module and the jacket.
The man was airlifted to hospital, where he underwent surgery to amputate his leg.
As a result, the case was probed by the Crown Office and Procurator Fiscal Service Heath and Safety division, a Scottish body whose responsibilities include investigating "sudden or suspicious deaths."
Both contractors pleaded guilty when the case was brought to court.
Following the case, HSE Principal Inspector Marc Nunn said: "Mr Murray lost his leg in this avoidable incident that could have easily had far worse consequences. The case demonstrates the importance of adequately planning and assessing the risks, and implementing sensible management controls, for all lifting activities.
"Both Talisman and Scaldis should reasonably have foreseen the potential for the load to move, and taken measures to prevent their personnel being exposed to the hazards of a swinging load."
The Beatrice demonstration project is Scotland’s second largest offshore wind farm after the 180MW Robin Rigg wind farm.