Allan was director of communications for News Corp.-owned BSkyB after serving the Blair government and built the agency with BSkyB as a flagship client.
Portland counts blue chips like Coca-Cola and McDonald’s, as well as tech heavyweights Google U.K. and Facebook among its diverse client roster.
Omnicom will have PC working closely with its Brussels-based European political PR unit, g+ Europe. Allan said the two firms have collaborated over many years and “have a great deal in common.”
The firm will fall under OMC’s Diversified Agency Services unit, which includes its major PR operations like Ketchum and Fleishman-Hillard.
The U.K. press reported last year that Allan was talking with Publicis. The firm's 2010 revenues were placed in the £6-7M range. Allan reportedly turned down the top communications job in Blair's government in 2005 so that he would not have to dismantle Portland.
Based in London, the firm has operations in New York and Nairobi.