New and existing contract extensions with Canadian energy giant Nexen Petroleum
Under the terms of the new deal, Orion will provide manpower services for Nexen Petroleum UK's Golden Eagle project, comprising the Golden Eagle and Peregrine North Sea reservoirs located 43 miles from Aberdeen.
The Golden Eagle development is projected to produce up to 70,000 barrels of oil a day.
Orion has also agreed a three-year extension of an existing recruitment contract for Aberdeen, London and offshore installations.
Both contracts will be worth £20 million a year until 2017.
Steve Greig, associate director of Orion Group, said: "These deals amount to £20million per year and will have an immediate impact on Orion Group with our focus on the opportunities which will arise over the next five years.
"We have had a dedicated team working with Nexen to ensure its expectations are not only met, but exceeded, and were confident that the relationship will bring mutual rewards and successes.
"We were pleased that our reputation for quality and high levels of support helped us to secure these deals.
"Being appointed to work with Nexen as a global business partner underlines Orion's strength and ability to attract some of the worlds finest energy specialists and it is encouraging to be in position to provide some 140 workers to the sector over the coming years."
Inverness-based Orion Group was established in 1987 by the group's current chairman Alan Savage, and now employs more than 340 staff across eight UK and 19 worldwide offices.
Orion's clients include Shell Expro, Nexen, Technip, BP International, Talisman, ExxonMobil, Total, and Wood Group PSN.