The firm was found guilty of breaching the Health and Safety at Work etc Act, but two company directors and the project manager were acquitted.
Michael Adamson, 26, was killed in August 2005 when he came into contact with a live conductor in a cable on which he was working.
Mr Adamson, a qualified electrician, was working at the JJB Sports Centre and Retail Outlet, which was under construction at the Gallagher Retail Park in Dundee when the incident occurred.
The Dundee Sheriff Court heard that, despite being labelled 'not in use', the cable he was working on was live.
HSE principal inspector Jim Skilling said Mr Adamson was not provided with the necessary test equipment to prove the cable was dead, nor the means to securely isolate the circuit.
Mr Skilling, commenting after the case, said: "The industry's complacency in accepting dangerous practices is startling.
"Michael Adamson's death could have been prevented had his employer ensured that safe working practices were being carried out in accordance with the company's own written procedures. Managers and supervisors in this industry must take active steps to ensure that their electricians work safely."