Softbank Corp., Japan's third-largest mobile phone operator, is mulling possible investments in software or mobile phone content companies in India and Southeast Asia, Chief Executive Officer Masayoshi Son said Thursday.

"We just partner — we invest 20 percent, 30 percent," Son said at a briefing at the Mobile Asia Congress industry conference in Hong Kong. "We'd like to bring social games and others into Japan" from China.

The company owns stakes in the parent of China's Alibaba.com Ltd. and Yahoo Inc. of the U.S., and invested about ¥13.7 billion in 24 companies in Asia in the year that ended March 31, according to the Tokyo-based carrier's Web site. Softbank spent ¥35.5 billion on investments in Japan in the same period.