The City boss said: "We are close with Balotelli. Mario is on his way here."
Another of Mancini's targets, Aston Villa's James Milner, is also expected to sign for the north west club.
However, Milner's move may have to wait until after the opening weekend of the Barclays Premier League season.
Mancini said: "We need another two or three days for this situation. We need everyone to be happy."
Balotelli's Inter Milan team-mate Marco Materazzi was quoted on www.gazzetta.it as saying: "I am happy for Mario, but we will be weakened by his departure."
Source: PA
Source: PA