IKM Consultants has taken over Poseidon Consulting Services (PCS) after buying 100% of its shares from Siemens in Norway.
Poseidon, which mainly focusses on subsea and pipeline work, has about 150 staff, which will be taken in to IKM's business.
The acquisition includes PCS' UK division, including current contracts and frame agreements.
IKM said: "This will make IKM Consultants one of the three largest companies offering consultancies to the Norwegian oil and gas industry, and will strengthen our position in the market."
Per Oscar Knutsen, managing director of IKM, said: “Size is important in order to meet the demands for quality and scope, and is necessary in requiring frame agreements from the market’s largest participants. These will contribute to interesting job possibilities that will make us attractive for potential consultants."
He said IKM is experiencing increasing demand from other parts of Europe as well as Asia. As a result, it is growing its office in Aberdeen and following its customers into the Asian market.
“There will be much activity in our market for many years to come, and IKM will take part in this increased activity, both in Norway and internationally”, said Arne Vervik, executive vice president in the IKM Group.