Japanese social game developer DeNA CO., acquires San Francisco-based Ngmoco for $400 million. Ngmoco is a game developer company with products running on Apple’s iPhone. The acquisition is DeNA’s third involvement with a US company over the past 12 months taking, into account the acquisition of Gameview Studios Llc last month. The deal involves cash, shares and warrants, and will be closed on Nov. 9.

According to their statement, the joint effort of DeNA and Ngmoco will create the world’s largest mobile social games platform company. The Tokyo-based company entitled the shareholders and employees $300 million in cash and securities. An additional $100 million will be added if performance goals are met.

“The deal is designed to help DeNA create a unified platform that will allow developers to make games that run on both Apple and Android operating systems, according to the statement. Ngmoco will also help DeNA to make its Mobage Town gaming site into a global service, the statement said.”

Mobile gaming has all but taken over this year, and it’s gaining some heavy interest from big players, namely Facebook, Google and Apple. The trend just keeps growing, and there’s lots of room for global growth. Several Japanese and Chinese game platforms have made their way to the Android Market in particular, launching a host of games from within their own networks.

The Ngmoco acquisition represents yet another way in which the mobile market will ignite a new kind of global expansion, with companies like Dena able to take advantage of the massive and ready US market. Competitor Zynga is expanding across the globe as well, having made a few key acquisitions and opening offices in Europe and China within the past six months.