The project has already involved the construction of the skyscraper headquarters of Italy’s biggest bank UniCredit by Argentine architect Cesar Pelli.
“Porta Nuova is one of the most prestigious urban renovation projects in Europe,” real estate giant Hines Italia and Qatar Holding said in a statement.
Texas-based Hines’ Italian arm leads the project.
“Land is Italy’s most important natural resources, and we are confident it can be a strategic engine for development and economic growth,” said Manfredi Catella, chief executive of Hines Italia.
“The agreement is a fundamental signal for the Italian economic system and the international capital market,” he was quoted as saying.
Italy’s property market has plummeted in recent years, with the number of sales falling by more than a quarter in 2012 compared to the year before.
Qatar Holding last year bought a luxury resort on the Italian island of Sardinia with one of the country’s most beautiful stretches of coastline.