Aon has acquired RGIT Ethos Health and Safety, the occupational health business of global training provider RGIT Montrose Group.
The buy is part of Aon's push to become a leading specialist occupational health service provider and consultancy.
Aon refused to reveal how much it paid for the company.
All the UK assets, contracts and ongoing business of Ethos Health and Safety, including 42 employees, premises in Oxford and Dorset and Ethos's Medic Agency, have transferred to Aon Occupational Health, which is part of Aon's employee risk solutions division.
The Aberdeen office will undergo a transition period with services being provided both from Ethos's King Street office and Aon's Foresterhill Road site until preparations to relocate to Foresterhill are finished.
Aon acquired Liberty Occupational Health a year ago to create Aon Occupational Health.
Since then, it has also bought the occupational health business of ICI in Teesside and now employs 210 staff in six centres.