Terms of the transaction are not being disclosed.
Gramercy Europe will become an operating business of U.S. real estate money manager Clarion and be rebranded as Clarion Gramercy. Clarion Gramercy will maintain its offices in London, Berlin and Barcelona.
"We are very excited to broaden the investment reach of Clarion Partners into European markets," Clarion Partners CEO David Gilbert said in a statement.
Gramercy Europe CEO Alistair Calvert will continue to lead the Clarion Gramercy business.
Gramercy Europe has $16 billion in assets under management; Clarion Partners has $50 billion in AUM.