AC Milan have denied reports that they have started negotiations to sell Ronaldo to Brazilian outfit Flamengo.
Ronaldo made 14 appearances for Milan last season
The club issued a statement after Flamengo vice president Kleber Leite told Italian media he had been given permission to speak to the player.
"AC Milan denies that it started a negotiation with Flamengo for the transfer of Ronaldo," said the club.
"It denies also having authorised the Brazilian team for an eventual deal with the soccer player."
Ronaldo signed for AC Milan in January 2007 from Spanish giants Real Madrid.
But the three-time world player of the year has struggled to impress Milan coach Carlo Ancelotti and has also suffered a series of injuries.
The 31-year-old has made just one appearance for the European champions this season.
"We have made contact with the player and we are certain he can launch his career again here," Leite told Italian paper Gazzetta dello Sport.
Ronaldo is in Brazil receiving treatment for a shin injury, but Leite claimed it would not hinder the transfer.
The striker's contract finishes in June 2008, but Milan will be hoping to get back some of the £5m they paid Real for the striker's services.
Flamengo are keen to upstage Sao Paulo, who secured a six-month loan for Inter Milan's Brazilian international Adriano last week.