Online game publisher Nexon Corp. announced that its worldwide revenues jumped up to ₩703.6 billion ($561.5M) in 2009, a 56 percent increase over 2008's revenues of ₩450.8 billion ($359.7M).

The South Korean-based firm also revealed that its North American publishing arm, Nexon America, posted a 31 percent growth in revenues to ₩57 billion ($45.5M) in 2009 over ₩43 billion ($34.3M) the previous year. For the first time in the company's history, non-Korean contributions made up the majority of Nexon's global revenue.

Nexon attributed the dramatic revenue increases to the popularity of Dungeon & Fighter, which has brought in over 200 million registered users and enjoyed a maximum concurrency of 2.4 million players from China, Japan, and South Korea. The company intends to launch the free-to-play MMORPG in North America as Dungeon Fighter Online on June 9th.

Its other free-to-play online titles like Maple Story and KartRider also contributed to the revenue growth. MapleStory has attracted some 95 million worldwide registered users (over six million in North America online), while KartRider has more than 200 million registered players around the world.

Nexon America's revenues are also off to a good start for 2010, as it's already grown more than 28 percent in the first quarter of this year compared to same period in 2009. The North American division points out that it's preparing to launch two titles: Vindictus (known as Mabinogi Heroes elsewhere) later this year and Dragon Nest in 2011.

"Nexon has perfected the free-to-play model worldwide and has applied it as a winning formula to very outstanding games," says Nexon America CEO Daniel Kim. "Here at home, we have been able to fend off the tough times and continue growing our revenues while adding more and more players to our games."

The CEO adds, "Going forward, Vindictus, Dragon Nest, and Dungeon Fighter Online represent the next generation of free to play games that should appeal directly to gamers in North American."