Real estate giant Re/Max, which comprises over 125,000 agents in more than 110 countries and territories, is searching for a new home for its U.S. media buying and planning services.

“Re/Max engages in this process every few years to remain competitive and ensure it continues to partner with the agency that will deliver maximum results for its vast network,” a brand representative said in a statement.

Carat is the incumbent media agency of record on the account and will be defending in the review, which is expected to conclude by the end of the year, according to a source with direct knowledge of the review. Carat has yet to respond to a request for comment. Centro has also acted as a digital partner and consultancy for the brand for several years, providing services ranging from technical infrastructure (Re/Max’s online properties run on its proprietary software) to programmatic buying. It is unclear at this time how the review might impact Centro’s relationship with the brand.

“Re/Max is currently operating its digital media business on top of Basis, Centro’s software,” said Centro founder and CEO Shawn Riegsecker in a statement. “At the least, I’m confident Centro’s relationship to Re/Max will remain intact via its installation of Basis. Whether or not Centro still provides digital marketing services to Re/Max or [its] new AOR remains to be seen.”

The review is being conducted by Media Sherpas, the consultancy co-created by Nancy Hill following her departure as 4A’s CEO in 2017, along with Zach Rosenberg. This represents the first review conducted by Media Sherpas, which primarily helps brands and agencies navigate the media landscape. Hill declined to comment.

Re/Max recently changed up its creative approach as well, with a Wes Anderson-esque 2018 campaign from agency of record Camp + King marking a stylistic departure from previous campaigns.

Re/Max spent a little over $36 million on measured media last year, down from around $39 million in 2017, according to Kantar Media. 2019’s first quarter total was just under $10 million.