Both companies are owned by the Interpublic Group of Companies, although Interpublic is looking to dispose of Brands Hatch Circuits, which is losing money. The £2m account was previously with Total Media.
Brands Hatch Circuits organises motorsports events including the British Touring Car Championship and the British Superbike Championship, as well as owning and running Brands Hatch and managing Silverstone.
Troubles at Brands Hatch Circuits are one of the many contributing factors to Interpublic's plunging share price during 2002, with Octagon Motorsports losing $135.8m (£85.4m) after being profitable in 2001.
When Interpublic announced the name change last week, it claimed it was to eliminate confusion and differentiate the division from other areas of sports marketing in the Octagon Group.
Robert Ditcham, commercial director of Initiative Media, said: "We have worked with Brands Hatch Circuits before and are delighted to have renewed this relationship."
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