Rovio Mobile – developer of the hugely successful Angry Birds game – is to enable operator billing for the app via the launch of its own in-app payments system called Bad Piggy Bank. An initial deal with Finnish carrier Elisa will see customers with the free ad-supported version of Angry Birds able to pay to remove the ads. Other global operator deals will follow. Mobile Entertainment cites Rovio’s Peter Vesterbacka as stating: “The plan is to work with several third party payment providers – the first one is Fortumo.”

Angry Birds has topped the charts of paid-for Apple apps for months in about 60 countries including the United States and Britain, and reached 50 million downloads on Friday (12 months after the game was launched). It aims to reach 100 million downloads by mid-2011. Check out our exclusive profile of Rovio here.