Ronaldo is poised to travel to Italy to undergo a medical with AC Milan after the Serie A club made a six million-euro (4 million-pound) offer for the Brazilian striker, Spanish media reported on Thursday.
Daily El Mundo said that Ronaldo would sign an 18-month contract with Milan who would offer him the chance to end his career at the club if he lives up to expectations.
Marca's Web page said Italian intermediary Ernesto Bronzetti, who has been involved in the negotiations, had said the two clubs had reached an agreement.
The three-times World Player of the Year had been tipped to leave Real Madrid ever since coach Fabio Capello made it clear the 30-year-old did not feature in his plans.
Ronaldo has been a long-time target for AC Milan who made a reported bid of between 15 and 18 million euros for the striker in the close season.
A transfer to Milan would represent a return to familiar territory for Ronaldo, who played for Inter Milan between 1997 and 2002.