Seven agencies have been added to the new roster. They join the seven that were on the previous roster, which was compiled in 2000.
The new agencies are BLM Media, Carat, Experience, MediaCom, MindShare, Rise Communications and Universal McCann.
The seven agencies that have been reappointed to the COI roster are Manning Gottlieb OMD, Mediaedge:cia, Starcom, Naked Communications, PHD, ZenithOptimedia and Ingram.
COI claimed the enlarged roster would give government departments greater choice. Jeremy Found, COI's head of media, said: "The new roster gives us access to a range of agencies, from the largest through to the specialist communications planning agencies, to suit the diverse range of government campaigns."
Communications planning assignments are usually allocated by COI following a pitch. Often, COI will pair a media agency with a creative agency from its roster.
COI finalised its media buying arrangements last week when it appointed Carat to handle its cinema buying business. Carat also handles television buying for COI, while MediaCom manages press buying and Starcom radio buying.
The government body also revamped its creative and direct marketing rosters to reflect changes in the agency landscape.