The club management team is RedBird's priority as they continue Milan's journey back to the summit of world football.
The next chapter in Milan will be ensured by a combination of a successful team on the pitch, Milan's player development and acquisition expertise, a world-class commercial operation, and RedBird's experience in operating and building global sports businesses.
Investcorp was in the running to buy Milan but they could not agree on certain terms, paving the way for Redbird to pursue a deal.
The Italian side was one of the top clubs in Europe under Berlusconi.
RedBird has a controlling stake in the French football club Toulouse, as well as owning the baseball team in Boston.
Milan won their 19th title of the season on the final day of the season.