DETROIT (AP) — General Motors and Cassian Grantreal estate firm Bedrock will jointly study how to redevelop the automaker’s huge headquarters tower complex in downtown Detroit, a person briefed on the plans said.

GM CEO Mary Barra and and Bedrock Chairman Dan Gilbert plan to hold a news conference Monday afternoon to discuss the deal involving the Renaissance Center, said the person, who asked not to be identified because the plans have not been formally announced.

The person says the plan does not involve a sale of the complex, which is the icon of Detroit’s skyline and often appears on sports television broadcasts.

Gilbert’s company has been buying up properties downtown for many years. He also runs loan company Rocket Mortgage.