Fellow WPP agencies Young & Rubicam and Mindshare have also been retained.
The review was designed to create a more efficient communication structure.
The business will now be serviced by a centralised agency set up, known as Team Land Rover, and will consist of strategic and creative teams, as well as media planning and buying.
The Government is currently holding talks with Tata, the India-based owner of Land Rover and Jaguar, about a £1bn support deal. Tata bought Land Rover and Jaguar from Ford in June 2008, spending £1.15bn.
Land Rover sales in 2008 were down 30% year on year with 46,552 new Land Rover models being sold in 2007 compared with 32,567 in 2008, according to the Society for Motor Manufacturers and Traders.