Yoshikazu Tanaka, Japan\'s youngest billionaire, is considering an overseas listing of the Gree Inc. social-networking company he founded amid the busiest year for US Internet-related initial public offerings since 2000. \"Numerous Japanese companies have listed overseas after doing so on the Tokyo Stock Exchange,\" 34-year-old Tanaka, owner of the nation\'s second-largest networking service, said in an interview in Tokyo on Monday. \"We would like to consider such an option as well.\" Such a move would allow Gree to join LinkedIn Corp. and China\'s Renren Inc. among companies capitalising on the growing investor appetite for social-media stocks. The number of internet-related filings for IPOs in the US has climbed to the highest in 11 years, according to data compiled by Bloomberg, including Zynga Inc. and Groupon Inc. \"Before Gree considers an international expansion, they should strengthen their business structure,\" Yusuke Tsunoda, an analyst at Tokai Tokyo Securities Co., said yesterday. \"They should also focus on the domestic smartphone market before an international expansion.\" Article continues below More than 50 Internet-related companies have filed for IPOs in the US this year, the most since 164 companies in the industry announced plans for initial offerings there during all of 2000, data compiled by Bloomberg show. Raising profile An overseas listing would help Gree raise its profile outside Japan, and the social-networking site operator isn\'t in need of funding, Tanaka said. The Tokyo-based company, which in April agreed to buy California-based OpenFeint Inc. for $104 million (Dh382 million), may continue to pursue acquisitions as it seeks to expand beyond Japan, he said. Gree slid 0.6 per cent to 1,728 yen (Dh78) in mid-morning on the Tokyo Stock Exchange, valuing the company at $4.9 billion. The shares have gained 67 per cent this year, compared with a 2.7 per cent decline in the benchmark Nikkei 225 Stock Average. Tanaka set up Gree in 2004 as a social networking service. Two years later, KDDI Corp., Japan\'s second-largest mobile-phone operator, decided to invest in Gree to expand its game business. KDDI owns seven per cent of Gree shares, while Tanaka controls 48.9 per cent, according to Bloomberg data. Gree now has 25 million user accounts. It posted a profit of 4.7 billion yen in the year ended March on revenue of 16.37 billion yen, according to Bloomberg data. \"If the Japanese market shrinks, we would need to be a global company, or our business would shrink,\" said Tanaka, whose wealth was estimated at $2.2 billion according to Forbes magazine\'s latest list of billionaires. He aims to boost user numbers to a billion from the 100 million now when combined with OpenFeint.