In a statement, Aegis said ICUC "provides people-powered, strategic direction to some of the world's most socially engaged brands including Chevron, Intel and Starbucks."
Terms of the deal were not disclosed, but Aegis said ICUC had gross assets of $1.4 million.
Aegis said the immediate benefit of the acquisition would be to integrate ICUC's community management and social media expertise to enhance iProspect's social media services.
The deal comes as Aegis has entered active negotiations to sell its Synovate marketing and media research division to Paris-based Ipsos. That potential deal has also sparked renewed speculation that a slimmed down Aegis Group might itself go into play, most likely as a merger with Paris-based Havas, because the two agency holding companies share a common top shareholder, French financier Vincent Bollore.