The 22-year-old has spent three seasons in the Inter first team, featuring in successful Coppa Italia, Italian Supercup and Club World Cup campaigns.
Obi joined the Inter youth setup at 14-years-old and was spotted by Jose Mourinho, who drafted him into the senior squad where he went on to make 38 appearances.
However, the Nigerian international only made four appearances for the Nerazzurri last season and has subsequently been loaned to Parma.
Parma coach Roberto Donadoni will be hoping Obi will be a catalyst to his side's campaign as they look to improve on a start which has seen them lose and draw their opening two fixtures.
Previously, in 2011 Parma were sold half of Obi as part of the deal surrounding Nwankwo Obiora but the player remained at Inter before the Italian giants bought him back for 3.2million euros in 2012.