Angry Birds developer Rovio announced a US$42 million Series A investment in the company to “facilitate its strategic expansion,” stating that the cash will “transform Rovio’s growth, allowing it to increase its reach internationally, and across markets including mobile, social media and other platforms, and via merchandising and media production and partnerships.” The round was co-led by Accel Partners, the venture capital firm which has backed companies including Facebook, Groupon and AdMob, and Atomico Ventures, the venture capital firm created by Skype co-founder Niklas Zennstrom.

According to Rovio, Angry Birds is played by 40 million active users monthly. It says that 40 percent of new customers on the iOS platform purchase “Angry Birds” virtual goods, while sales of Angry Birds toys have passed 2 million units. The company is planning to offer an “online Angry Birds experience towards summer 2011,” as well as developing Angry Birds games for all major consoles later in the year. It also said it will build its franchises in “merchandising and broadcast media.”

According to a recent Wired report, Rovio has so-far managed to generate more than EUR50 million of revenue from its Angry Birds activities.