Dozens of Petrofac workers have this week transferred over to North Sea operator EnQuest.
A total of 146 staff have moved over from the energy services firm.
It is understood the workers were already contracted to the Heather, Thistle and Magnus platforms, as well as the EnQuest Producer floating production vessel and Northern Producer rig.
EnQuest decided at the end of last year to take them on, with the transition being completed earlier this week.
The firm said the move was good news for staff and improves efficiencies.
A spokesman said: “We looked at our workforce and decided to offer some career development. It was a good idea to in-house some of the skills in the business.
“Many of them were already subcontracted to those facilities.
“It helps efficiency internally and provides opportunities for staff as well.”
A spokeswoman for Petrofac said: “EnQuest decided at the end of 2018 to take these roles in-house and the process concluded yesterday following a safe and smooth transition.”
It comes after EnQuest announced a review of rota patterns for several North Sea assets in February to help streamline the business.