The addition grows Portland’s office in Doha to 20 members of staff, who provide services in corporate, government advisory, global impact, and content and brand practices.
Portland has had a presence in Qatar since 2014 and the country is one of its most important regional hubs, with several Qatari clients.
As part of the acquisition, Patrick Forbes, founder of Forbes Associates, has joined Portland as a partner in its corporate practice.
"I founded Forbes Associates in Qatar almost 11 years ago and I am incredibly proud of what the agency achieved," Forbes said. "I have always said that I would not sell the business unless the right partner came along."
Portland managing partner Steve Morris added: "Together, we will bring our clients in the Middle East unrivalled local experience combined with a global reach. I can already see that this is happening through the work that is coming out of our office in Doha since the acquisition. It is certainly an exciting time for Portland in this market."
Portland supports clients in more than 85 countries through offices in London, Doha, Washington DC, New York and Nairobi. The business has a global headcount of 250 consultants.