That means the current agreement will now run to 2016.
Under the new deal, Bell will expand its Athletes Connect program which currently gives athletes access to free mobile phones.
The telecommunications company will also help build a new social media delivery platform for athletes.
The announcement comes just over a month after Air Canada extended its Olympic sponsorship deal to 2016.
The Canadian Olympic Committee made the announcement at the London Games.
Financial details were not revealed.Suggest a correction