OMD will be responsible for overall media strategy on corporate campaigns, such as its sponsorship of the Euro 2008 football tournament, as well as the buying.
OMD won the account after a pitch against the incumbent Vizeum and ZenithOptimedia. The account will be run out of Germany by a unit called K360 Media, which has been created specifically for Kia.
Nikki Mendonca, the president of OMD in the EMEA region, said: "We look forward to leveraging new opportunities such as Kia's sports marketing where we help to maximise their involvement in Euro 2008."
The move follows the recent appointment of Initiative in the US to handle Kia's local planning and buying alongside the Hyundai brand.
Separately, Kia is holding a creative pitch to find a pan-European agency to develop a campaign for its C'eed hatchback model.