Countryside Properties is one of Space & Time's largest accounts, out of total billings of 拢55m.
The agency's managing director, Peter Jones, confirmed that he would be re-pitching for the account.
He added: "We have had this business for four years and, given the changes happening in the marketplace, it is totally expected of any self-respecting company to review its marketing costs."
The agency recently picked up the 拢10m Westbury Homes account from Basingstoke-based agency, Tri-Direct.