Kaka, Brazil's 2007 World Footballer of the Year, completed his transfer from Italian Serie A side AC Milan to Spain's Real Madrid late on Monday, both clubs said.
The 27-year-old signed a six year contract with the Spanish giants for a reported fee of 65 million euros.
While both clubs refused to confirm the fee, it could be the second biggest ever transfer, only next to that of French great Zinedine Zidane, who cost Real Madrid 75 million euros in 2001.
Real chairman Florentino Perez has established a 200 million euro budget for players, hoping to overtake arch rival Barcelona next season.
Kaka, who is in Brazil for their 2010 World Cup qualifier with Paraguay, has been at AC Milan since arriving from Sao Paolo in 2003, scoring 70 goals in Serie A and 23 in the UEFA Champions League.
He has won the 2007 Champions League, the 2004 league title, two European Super Cups and the world club championship in 2007.
(Xinhua News Agency June 9, 2009)
