Japan's second-largest social-network game operator, Gree has agreed to buy Funzio for a sum of about $210 million in cash in its largest acquisition deal ever.

The acquisition, which is expected to close this month, will allow the company to add games for mobile phones, according to a statement from Tokyo- based Gree. The company will fund the purchase of Funzio through bank loans, according to the company.

Funzio, a San Francisco-based mobile game developer has developed popular games for mobile phones like Crime City. Gree, which was founded by billionaire Yoshikazu Tanaka, is aiming to expand overseas as it faces a slow growth in the domestic market due to factors like imposition of self-regulation in the country.

Gree will gain access to several games including "Kingdom Age" and other software developers though the acquisition. The statement from the company also pointed out that Gree had a total of 190 million users as of December. It also said that there have been more than 20 million downloads of Funzio's games through social networks including Facebook and Google.

Gree rose as much as 2.9 percent to 2,158 yen and were trading at 2,155 yen at the time of reporting this morning.