Lawmakers have wrestled over what to do with Fannie and Freddie since the mortgage-finance giants were taken under U.S. control as credit markets collapsed in 2008.
Mayopoulos has led Washington-based Fannie Mae since 2012, and lawmakers have grappled with what to do with the company and smaller rival Freddie Mac throughout his tenure.
In the first half of 2018, $22.5 billion of properties such as office towers and apartment complexes changed hands, up 34 percent from a year earlier, data from brokerage Cushman & Wakefield show.