Ibrahimovic is believed to be keen on a move away from Paris Saint-Germain this summer and Raiola met with Milan chief executive Adriano Galliani on Tuesday.
The 33-year-old, who has one year left on his current deal, is the subject of interest from a number of European clubs, with Premier League sides Chelsea, Liverpool and Arsenal reportedly among them.
Former club Milan, where he spent two years until 2012 and scored 28 Serie A goals in 32 appearances. are believed to be willing to offer him a three-year contract.
Ibrahimovic, a national hero in Sweden with over 100 caps and 54 goals, has accumulated some of the biggest transfer fees in the history of the game, with moves between Malmo FF, Ajax, Juventus, Internazionale, Barcelona, Milan and PSG fetching a total of ??133.2m.
Ibrahimovic moved to PSG in 2012 for ??15.7m and has scored 75 goals in Ligue 1 in 88 starts and 15 goals in 22 appearances in the Champions League.