The 28-year-old insisted he was fully fit despite concerns about his lifestyle and attitude in Spain.

"I have always lived a regular life and I will continue like that. I am in good physical condition," he said.

"Every player dreams of playing for Milan. It is a special emotion and I hope to bring happiness to the fans."

Thousands of fans turned up at the stadium to welcome Ronaldinho to the club, with the San Siro nearly half full.

"I already feel at home here," he added, speaking in Portuguese.

"It was a beautiful period (at Barcelona), we won important trophies but after recent disappointments we decided together to go our separate ways.

"Here I can go back to being happy and to reaching new personal and team objectives."

City had reportedly bid £25.5m for the player, but AC Milan are believed to have paid considerably less for him.

Ronaldinho helped Barcelona win back-to-back Spanish league titles (2004-05, 2005-06) and the Champions League in 2006, but failed to cement a regular place in the starting XI last season because of injury and fitness problems.