Square Enix USA has increased its stake in UIEvolution to 100%, thereby making the Bellevue, Washington-based developer a wholly-owned subsidary. In December, Square Enix announced a strategic investment of $4 million US in the wireless network specialist and became the company's third largest shareholder. Following continued popularity of its cell phone-based services in Japan, Square Enix has begun its expansion into the North American mobile market last year, by inking an agreement with Verizon Wireless and earlier this year with AT&T Wireless.