An appeal will be lodged by Statoil after losing a court case over working hours at its Kårstø complex north of Stavanger.
The Karmsund district court, sitting as a labour tribunal, found that the working day should be calculated from the time people pass through the main gate of the facility.
This decision represented a victory for the Norwegian Oil and Petrochemical Workers Union (Nopef) and the Norwegian Petrotechnical Union (NPTF).
Statoil, which argued that working hours should be calculated when employees arrive at their workplace within the complex, believes the judgement breaches established principles.
The appeal will be submitted to the Gulating Court of Appeal for south-west Norway immediately after the New Year.