Rovio could move ahead with an initial public offering (IPO) next month in a move that would see the Angry Birds maker valued at $2 billion. According to Bloomberg, which claims to have spoken with "familiar with the matter," the Finnish company will look to raise around $400 million from a local market listing. It's thought proceeds from the IPO will help finance the production of the second Angry Birds movie -- the first made $350 million at the box office on a budget of $73 million -- and the development of new game titles. This isn't the first time an IPO has been rumored. Back in June, news outlet The Information claimed the company was mulling over its options, and then Rovio itself fuelled the fire by confirming "a stock exchange listing at some point in the future could be possible." At the same time, it was also being reported that Chinese internet giant Tencent wanted to purchase the Nordic outfit for around $3 billion.