A COI study, due out in November, has shown that different creative and planning approaches are required to communicate with ethnic minorities.
Peter Buchanan, the deputy chief executive of COI, said: "The UK is a diverse multi-cultural society - advertising content and media planning need to reflect this, and must embrace changes that are taking place from one generation to the next."
He explained how the recent census showed the extent of the changing UK demographic, citing how Leicester's Asian population outnumbers its white population.
Patricia Macauley, the black and minority ethnic communications manager for COI, said: "There are a number of niche agencies that specialise in this area that may not be suitable for our mainstream rosters. By setting up the BME-specific roster, we can access a wider range of specialists."
The new roster will be composed of advertising, PR, outreach and partnership marketing specialists. COI is seeking agencies with experience in communicating with communities from Pakistan, Bangladesh, India, Africa, the Caribbean and China.
The announcement follows COI research, published in July, that found mainstream media were more effective at targeting blacks and Asians than specialist TV and radio channels.