TOKYO May 25 (Reuters) - DeNA Co said its founder and CEO Tomoko Namba, a rare female top executive in Japanese business, will step down as head of the Internet service firm due to a family health issue but will continue to play an active role in management as a board member and adviser.
Namba, a Harvard MBA holder who built DeNA from an Internet startup in 1999 into a major social gaming company, will be replaced by Isao Moriyasu, now DeNA`s chief operating officer and general manager of its social media business head office.
The move is effective June 25 at the close of the company's annual shareholders meeting.
"Isao Moriyasu has led Mobage, our highly successful core business, since its launch in 2006," Namba said in a statement. "I strongly believe he will be able to act quickly and decisively in this rapidly changing industry, to grow our billion-dollar company while making it truly global."
Under Namba, DeNA has grown its mobile-only social game business Mobage-town into a site of more than 20 million users in Japan, and has been widening its game offerings across multiple platforms including PCs and cellphones.
DeNA is also expanding aggressively in the United States. Last October, the company paid $403 million for ngmoco Inc, a U.S. developer of games for Apple Inc's iPhone and Google Inc's Android phones. (Reporting by Antoni Slodkowski; Editing by Chris Gallagher)