It will also give the firm expertise in advising on social and economic regeneration projects, one of IMC Consulting's main strengths.
WYG chief executive John Purvis said: "Though White Young Green has traditionally concentrated on the UK market, we've been looking for the right opportunity to grow abroad.
"IMC Consulting offers strategic advice to high-level institutions such as the European Commission, the World Bank and the Department for International Development."
He added that the acquisition of British-based firm IMC Europe was intended to expand WYG's operations in the UK engineering sector. IMC Europe has an annual turnover of £4m and provides multidisciplinary services to UK government departments.
IMC Consulting has 156 staff at its headquarters in Nottinghamshire and 313 associates located in the UK and overseas. It has other centres in Poland, Turkey, Romania and the CIS. It has an annual turnover of £29m.